We evaluated the differences between radiologically measured size and pathologic size of renal tumors.
Materials and Methods
The data from 171 patients who underwent radical or partial nephrectomy for a renal tumor at Ajou University Hospital were reviewed. Radiologic tumor size, which was defined as the largest diameter on a computed tomographic scan, was compared with pathologic tumor size, which was defined as the largest diameter on gross pathologic examination.
Mean radiologic size was significantly larger than mean pathologic size for all tumors (p=0.019). When stratified according to radiologic size range, mean radiologic size was significantly larger than mean pathologic size for tumors <4 cm (p=0.003), but there was no significant difference between the sizes for tumors 4-7 cm and >7 cm. When classified according to histologic subtype, mean radiologic size was significantly larger than mean pathologic size only in clear cell renal cell carcinomas (p=0.002). When classified according to tumor location, mean radiologic size was significantly larger than mean pathologic size in endophytic tumors (p=0.043) but not in exophytic tumors. When endophytic tumors were stratified according to radiologic size range, there was a significant difference between the mean radiologic and pathologic sizes for tumors <4 cm (p=0.001) but not for tumors 4-7 cm (p=0.073) and >7 cm (p=0.603).
Our results suggest that in planning a nephron-sparing surgery for renal tumors, especially for endophytic tumors of less than 4 cm, the tumor size measured on a computed tomography scan should be readjusted to get a more precise estimate of the tumor size.
Kidney; Neoplasms; Pathology; Radiology
To evaluate the difference between radiographic size on computed tomography (CT) and the pathologic size of renal tumors using a contemporary cohort.
Materials and Methods
We retrospectively reviewed the records of 521 patients undergoing surgical resection of a renal mass between 2000 and 2007 who had tumor sizes recorded from both preoperative CT imaging and pathologic evaluation of the tumor specimen. Data regarding histologic tumor type were also extracted. The paired student’s t-test was utilized to compare the mean radiographic size as measured on CT with the mean pathologic size, and p values <0.05 were considered statistically significant.
For all patients, the mean radiographic size and mean pathologic size was 4.79 and 4.69 cm, respectively (p = 0.02). Therefore, on average, radiographic size overestimated pathologic size by 1 mm. In patients with a tumor size of 4 to 7 cm, radiographic size overestimated pathologic size by 0.21 cm (p = 0.007). However, no significant difference was noted in patients with a tumor size of <4 cm or >7 cm.
Using a contemporary cohort of patients, we observed a statistically significant overestimation of renal tumor sizes by CT imaging as compared to pathologic assessment. However, the overall difference between radiographic and pathologic tumor size was 1 mm, suggesting that CT provides an accurate modality with which to estimate renal tumor size.
kidney neoplasms/pathology; kidney neoplasms/radiography; retrospective studies; tomography, x-ray computed; nephrectomy/methods
To evaluate the accuracy of radiologic tumor size for making decisions regarding nephron-sparing surgery of localized renal cell carcinomas (RCCs), we compared tumor size measured by a preoperative radiologic modality with that measured in the pathologic specimen.
Materials and Methods
Between January 2003 and December 2007, a total of 186 patients with pT1 or pT2 RCC underwent radical or partial nephrectomy at our institute. We excluded 11 patients who had preoperative arterial embolization (n=9) or positive surgical margins (n=2), and a total of 175 patients were included in this study. Radiologic size was defined as the largest diameter on computed tomography (CT), and pathologic size was defined as the largest diameter of the surgical specimen of the tumor. We retrospectively analyzed the difference between radiologic and pathologic tumor size.
The radiologic and pathologic tumor sizes did not significantly differ (4.98±2.82 cm vs. 4.55±2.70 cm, respectively, p=0.152). In the subgroup analysis, the size difference was statistically significant only for tumor sizes of less than 6 cm. The size difference was largest in tumors of 3 to 4 cm, for which mean the radiologic size was 0.63±1.19 cm larger than the mean pathologic size (p=0.002). Histologic type had no significant influence on the difference between radiologic and pathologic size.
The tumor size of RCCs in preoperative CT seems to correlate well with pathologic tumor size. However, CT imaging may overestimate the size of a tumor in the small mass group (less than 6 cm). These results should be considered when making decisions about nephron-sparing surgery.
Renal cell carcinoma; Nephrectomy; Radiology
We evaluated the safety and accuracy of ultrasonography-guided percutaneous core biopsy collection in patients with renal masses.
Materials and Methods
From June 2008 to August 2012, 30 percutaneous core biopsies of renal masses were performed. The biopsies obtained were small tumors (<4 cm) with ambiguous radiologic findings or that met classic renal biopsy indications. The biopsy results were compared with the final pathological results after definitive surgical treatment. Ultrasonography was performed on the day after biopsy collection to rule out any complications.
The mean age of the patients was 57.7 years, and the mean tumor size was 3.39 cm. Twelve of the lesions were in the left kidney, and 18 were in the right kidney. All but one core biopsy contained sufficient material for histopathological analysis. The biopsy results showed 17 renal cell carcinomas (56.7%), 3 angiomyolipomas (10.0%), 2 oncocytomas (6.7%), 1 adenocarcinoma (3.3%), and 7 benign lesions (23.3%). A total of 18 cases underwent surgery, and the pathological results confirmed the initial biopsy diagnosis for 17 of 18 cases (94.4%). The one (5.9%) inaccurate biopsy result was found to be a urothelial carcinoma of the kidney. No needle tract seeding was found in the pathological specimens or on follow-up imaging. A small perinephric hematoma (1-2 cm) was seen in 5 cases (16.7%), but all patients remained hemodynamically stable.
Ultrasonography-guided renal biopsy is a safe, effective, and accurate method for evaluating small renal masses. This procedure may help in selecting treatment modalities for small renal masses.
Fine-needle biopsy; Kidney
Multilocular cystic renal cell carcinoma (MCRCC) is a recently described variety of renal cell carcinoma with characteristic pathologic and clinical features. The purpose of this study was to analyze the imaging findings of MCRCCs.
Materials and Methods
Ten adult patients with pathologically proven unilateral MCRCC who underwent renal US and CT were included in this study. The radiologic findings were retrospectively evaluated for cystic content, wall, septum, nodularity, calcification and solid portion by three radiologists who established a consensus. Imaging and postnephrectomy pathologic findings were compared.
All patients were adults (six males and four females) and their ages ranged from 33 to 68 years (mean, 46). On US and CT images, all tumors appeared as well-defined multilocular cystic masses composed of serous or complicated fluid. In all patients, unenhanced CT scans revealed hypodense cystic portions, and in four tumors, due to the presence of hemorrhage or gelatinous fluid, some hyperdense areas were also noted. In no tumor was an expansile solid nodule seen in the thin septa, and in only one was there dystrophic calcification in a septum. Small areas of solid portion constituting less than 10% of the entire lesion were found in six of the ten tumors, and these areas were slightly enhanced on enhanced CT scans. In all patients, imaging and pathologic findings correlated closely.
On US and CT images, MCRCC appeared as a well-defined multilocular cystic mass with serous, proteinaceous or hemorrhagic fluid, with no expansile solid nodules in the thin septa, and sometimes with small slightly enhanced solid areas. Where radiologic examinations demonstrate a cystic renal mass of this kind in adult males, MCRCC should be included in the differential diagnosis.
Kidney neoplasms, CT; Kidney neoplasms, US
To assess the clinical reliability of the Bosniak IIF category and to determine the proper radiologic follow-up duration and intervals for category IIF complex renal cysts.
Materials and Methods
We studied 201 patients with category IIF renal cysts from January 1996 to January 2011. Renal cyst progression to category III was defined as an increase in complexity of the cyst in follow-up radiologic studies. We monitored radiologic changes and progression of renal cysts during the follow-up period and analyzed the pathologic results of those patients who were treated surgically.
At a mean follow-up of 20 months, only 14 cases (7%) showed evidence of progression to stage III, with a mean time to progression of 11 months (range, 3 to 65 months). There were no significant differences in age, gender, cyst size, or change in cyst size between the progressive and non-progressive groups. Of 12 cases treated surgically, 10 cases (83.3%) showed renal cell carcinoma with pT1 stage, and there was no recurrence during postoperative follow-up of 23 months. Of the 187 patients without radiologic progression, 23 cases were treated surgically, and all of them showed benign cysts.
The IIF category showed significant clinical reliability by a low rate of radiologic progression and a high rate of malignancy in the radiologic progressive group but a low rate of malignancy in the non-progressive group. Although it is hard to decide on a proper follow-up duration because of the variable time to progression, too frequent follow-up study seems to be unnecessary considering that most malignant cases were of a low stage.
Carcinoma; Cysts; Disease progression; Kidney; Renal cell
Data correlating mode of presentation of renal cell carcinoma (RCC) with pathological prognostic factors is sparse from India. We compared RCC presenting incidentally with those presenting symptomatically with respect to pathological prognostic factors and assessed whether this could serve as a decision making resource for diagnosing small and more favorable tumors.
Materials and Methods:
The data were reviewed for 328 patients operated for renal tumors between January 2000 and October 2008 at our institute. The pathological factors (tumor size, stage, grade, histopathological type) in relation to the mode of presentation were analyzed according to 1997 TNM criteria. Statistical analysis was performed via the chi-square (Fisher exact) and Mann - Whitney U test. The statistical significance level utilized was P < 0.05.
Among the patients assessed, 93 (28.4%) had incidental diagnosis and 235 (71.6%) had symptomatic presentation. Sex and side distribution was not significantly different in the two groups. Mean tumor size was 5.75 ± 2.73 cm in incidentally detected RCC (IRCC) and 9.32 ± 3.70 (P < 0.001) in symptomatic RCC (SRCC). Stage I and II tumors were significantly greater in IRCC than SRCC (p<0.001 and 0.005 respectively) whereas stage III and IV tumors were significantly less in IRCC than SRCC. There was a predominance of higher grade tumors in SRCC, 50% being higher grades (Fuhrman's grade III and IV) in SRCC than 28.1% in IRCC (P = 0.003). There were 4 tumors with collecting duct histology in SRCC and none in IRCC. Sarcomatoid differentiation was present in 14 and 1 patient in SRCC and IRCC respectively.
Incidental detection of renal carcinoma as compared to symptomatic tumors is lower in India as compared to western world. Incidental tumors have significantly favorable pathological prognostic factors. Our results might form a basis for further studies on how to pick RCC at an earlier stage.
Incidental; pathology; symptomatic
The purpose of this study is to set guidelines for the management of renal angiomyolipoma (AML), clinical prognosis according to tumor size, in association with tuberous sclerosis complex (TSC), multiplicity, radiographic finding, and treatment modality.
Materials and Methods
Between March 1998 and October 2008, 129 out of 254 patients with AML who underwent surgical intervention or angioembolization were enrolled. Diagnosis of AML was determined by the presence of a low attenuated component on CT imaging or by pathological confirmation. Indications of treatment were intractable pain, hematuria, suspicion of malignancy, large tumor size, spontaneous rupture, and radiographically equivocal tumors in which a differential diagnosis was needed to rule out malignancy. Parameters including age, sex, tumor size, multiplicity, radiographic characteristics, association with TSC, and treatment modality were reviewed.
Age at presentation was 50.6 years and mean tumor size was 3.5 cm. Presentation symptoms were flank pain, hematuria, spontaneous rupture, and fatigue. 97 (75.2%) patients were incidentally discovered. 100 (77.5%) were females. 68 (52.7%) underwent nephron-sparing surgery (NSS), 35 (27.1%) radical nephrectomy, and 26 (20.2%) angioembolization. TSC was accompanied in 12 (9.3%) patients. No patient developed renal function impairment during the mean follow-up period of 64.8 months. Patients with TSC presented at a younger age, along with larger, bilateral, and multiple lesions.
Significant differences in clinical manifestations and treatment outcomes were noted in respect to tumor characteristics, association with TSC, and treatment modality. Considering the benign nature of AML, these parameters ought to be considered when deciding upon active surveillance or prophylactic intervention.
Angiomyolipoma; tuberous sclerosis; kidney
Patients undergoing serial cross sectional abdominal imaging to evaluate abdominal symptomatology may develop a renal tumor during their follow up of an unrelated disease process. Evaluation of such patients provides an opportunity to further define the radiographic inception, natural history and growth patterns of renal tumors.
Materials and Methods:
A review of two institutions’ renal tumor databases was performed for patients who developed an enhancing renal tumor with a prior normal cross sectional radiographic examination of the kidneys. Variables evaluated included: age, gender, tumor size at presentation, calculated tumor growth rate from negative scan to radiographic presentation and pathology in patients undergoing definitive treatment.
We identified 36 patients with an average age of 65 yrs (range 44-82). Mean tumor size on presentation was 2.3 cm (range 1.0 -5.0). Presumed absolute growth rate based on timing of initial negative imaging study and tumor diameter at presentation was significantly greater compared to observed absolute growth rate following tumor detection (0.71cm/yr versus 0.039 cm/yr), p =0.028. No difference was noted between presumed and observed tumor growth based on absolute change in tumor volume (1.44cm3/yr versus 5.37cm3/yr), p=0.203. Presumed relative growth rates based on tumor diameter (665%/yr versus 23%/yr) and volume (1397%/yr versus 169%/yr) were significantly greater compared to observed relative growth rates, p=0.005 and p=0.013 respectively.
The presumed growth rate of the tumors was significantly greater than the observed growth rate suggesting that tumor growth rates do not follow a linear patter throughout their development and progression.
renal tumors; active surveillance; natural history
Solid pancreatic tumors such as pancreatic ductal adenocarcinoma (PDAC), solid pseudopapillary tumor (SPT), and pancreatic endocrine tumor (PET) may occasionally manifest as cystic lesions. In this study, we have put together our accumulated experience with cystic manifestations of various solid tumors of the pancreas.
From 2000 to 2006, 376 patients with pancreatic solid tumor resections were reviewed. Ten (2.66%) of these tumors appeared on radiological imaging studies as cystic lesions. We performed a retrospective review of medical records and pathologic findings of these 10 cases.
Of the ten cases in which solid tumors of the pancreas manifested as cystic lesions, six were PDAC with cystic degeneration, two were SPT undergone complete cystic change, one was cystic PET, and one was a cystic schwannoma. The mean tumor size of the cystic portion in PDAC was 7.3 cm, and three patients were diagnosed as 'pseudocyst' with or without cancer. Two SPT were found incidentally in young women and were diagnosed as other cystic neoplasms. One cystic endocrine tumor was preoperatively suspected as intraductal papillary mucinous neoplasm or mucinous cystic neoplasm.
Cystic changes of pancreas solid tumors are extremely rare. However, the possibility of cystic manifestation of pancreas solid tumors should be kept in mind.
solid; cystic; pancreas; tumor
To identify size criteria for complex cystic renal masses that can distinguish renal cell carcinoma from benign cysts supplementing the Bosniak classification.
Materials and Methods
We reviewed the records of 97 patients who underwent surgery for complex cystic renal masses from January 2001 to April 2010. The pathological results were compared with the lesion sizes measured by preoperative computed tomography and other radiological features (contrast enhancement, irregularities of cyst walls and septa, and calcification) were also obtained for categorization according to the Bosniak renal cyst classification.
Malignancy was significantly associated with cyst size (>2 cm), male gender, and younger patient age (<50 years). According to the Bosniak classification, there was no category I cyst, and all 8 category II cysts were benign. However, 3 of 18 (17%) category IIF cysts, 21 of 39 (54%) category III cysts, and 29 of 32 (90%) category IV cysts were malignant. All category IIF cysts were benign in patients older than 50 years of age.
Many complex cystic renal masses smaller than 2 cm were benign. We suggest that lesion size should be taken into account when formulating treatment plans for complex cystic renal masses.
Kidney; cysts; kidney diseases; cystic; carcinoma; renal cell; computed tomography; X-ray
Despite aggressive screening, patients with hereditary renal cancers can present with large, multifocal tumors. We present oncologic outcomes in hereditary renal cell carcinoma patients treated with partial nephrectomy for multifocal solid tumors with the largest lesion greater than 4 cm.
Materials and Methods
Between 1995 and 2008, we identified 58 patients with hereditary RCC treated at our institution with partial nephrectomy for solid tumors greater than 4cm. The data collected included demographic parameters, tumor size, tumor pathology, and laterality. Overall survival and metastasis-free survival were calculated based on the information from the most recent follow up evaluation and imaging.
The cohort included 58 patients consisting of 41 (71%) patients with VHL, 10 (17%) patients with BHD, and 7 (11%) with HPRC. The mean age was 43.7 (range 18–63) and the mean largest tumor size was 5.3 cm (range 4–13). The mean number of resected kidney tumors was 6.4 (range 1–44). There was a predominance of nuclear grade 2 tumors 51 (85%) and a predominance of clear cell histology 44 (73%), followed by papillary type I histology 7 (11.7%). Overall survival of the cohort was 93% and metastasis-free survival was 96.5% at the median follow up of 45 months (range 2–163).
The metastasis-free and overall survival of our patients is similar to those reported in the literature series for patients undergoing partial nephrectomy for T1B tumors in the sporadic population. The presence of multifocality does not affect oncologic outcomes at an intermediate follow up. Partial nephrectomy can be offered to hereditary patients presenting with multifocal tumors greater than 4 cm.
partial nephrectomy; multifocality; renal cell carcinoma; clinical stage T1B; outcomes
To determine whether smaller tumor size is associated with less-aggressiveness in renal cell carcinoma (RCC).
Materials and Methods:
Series records of 505 patients diagnosed with RCC were retrospectively reviewed and the data concerning tumor size and pathological information were extracted and analyzed.
Five hundred and eight RCCs were identified. The mean tumor size was 5.02 ± 2.70 cm. No correlation was detected between the size of tumor and the histological subtype. The overall nuclear grade distribution was 57.1% and 42.9% for low-grade and high-grade disease, respectively. Each 1 cm increase in tumor size was associated with a significant increase in the odds ratio of high-grade disease by 1.46. 91.1% were found low-stage lesions and the odds ratio for the association of high-stage disease with each 1 cm increase in tumor size was 1.67. Multinomial models revealed that each 1 cm increase in the tumor size was associated with a 35% increase in renal capsule involvement and 66% renal vascular invasion. The cut-off point of tumor size in renal vascular invasion was 5.6 cm.
Tumor size is not an independent predictor for the histological subtype of RCC. However, it is closely correlated to histopathological features, with the indications that the greater the tumor size, the more aggressive potential the RCC is.
Pathology; renal cell carcinoma; size
The juxtaglomerular cell tumor (JGCT) is a rare renal tumor characterized by excessive renin secretion causing intractable hypertension and hypokalemia. However, asymptomatic nonfunctioning JGCT is extremely rare. Here, we report a case of nonfunctioning JGCT in a 31-year-old woman. The patient presented with a left renal tumor without hypertension or hypokalemia. Under a clinical diagnosis of renal cell carcinoma, radical nephrectomy was performed. The tumor was located in the middle portion adjacent to the renal pelvis, measuring 2 cm in size. Pathologically, the tumor was composed of cuboidal cells forming a solid arrangement, immunohistochemically positive for renin. Based on these findings, the tumor was diagnosed as JGCT.
In cases with hyperreninism, preoperative diagnosis of JGCT is straightforward but difficult in nonfunctioning case. Generally, JGCT presents a benign biological behavior. Therefore, we should take nonfunctioning JGCT into the differential diagnoses for renal tumors, especially in younger patients to avoid excessive surgery.
It is estimated that a quarter of a million people in the USA are living with kidney cancer. In clinical practice, the response to treatment is monitored by manual measurements of tumor size, which are time consuming and show high intra- and inter-operator variability. We propose a computer-assisted radiology tool to assess renal tumors in contrast-enhanced CT for the management of tumor diagnoses and treatments. The algorithm employs anisotropic diffusion, a combination of fast-marching and geodesic level-sets, and a novel statistical refinement step to adapt to the shape of the lesions. It also quantifies the 3D size, volume and enhancement of the lesion and allows serial management of tumors. The comparison between manual and semi-automated quantifications shows disparity within the limits of inter-observer variability. The automated tumor classification shows great separation between cysts, von Hippel-Lindau syndrome (VHL) lesions and hereditary papillary renal carcinomas (HPRC) (p < 0.004).
contrast-enhanced CT; kidney cancer; quantification; classification; computer-assisted radiology
The natural history and growth rates of untreated solid enhancing renal tumors is being defined through active surveillance series. Serial radiographic evaluation of patients who are not surgical candidates or refuse surgical treatment provides an opportunity to characterize the growth of untreated enhancing renal tumors. Here we evaluate factors which may help predict for radiographic growth during observation.
Methods and Materials
We reviewed our renal cancer database for enhancing renal masses that were radiographically observed for a period of at least 12 months. Variables examined included patient age, gender, lesion size on presentation, radiographic tumor characteristics, duration of active surveillance, linear growth rate, surgical pathology, development of new renal tumors, and stage progression.
109 patients with 124 sporadic enhancing renal tumors were identified undergoing a period of active surveillance of at least 12 months. Median patient age was 73 years (mean 69.8, range 35–87). 72% (78/109) of patients were males. Median duration of active surveillance was 26 months (mean 33.4, range 12–156). Multifocal disease was present in 9% (10/109) patients on presentation, accounting for 20% (25/124) of all tumors. Tumor size on presentation was a median of 2.0 cm (mean 2.61, range 0.4 – 12.0). Overall median tumor growth rate was 0.21cm/yr (mean 0.28, range −1.4 – 2.47). Observed linear growth rates were independent of patient age, gender, tumor size on presentation, multifocality, and radiographic characteristics (solid versus cystic), p > 0.05. Of the patients initiating a period of active surveillance 36% (39/109) eventually underwent definitive therapy. Malignant pathology was present in 90% (35/39) of patients undergoing treatment. In patients continuing active surveillance (64% (70/109)), 2.9% (2/70) developed de novo renal lesions and 1.4% (1/70) developed metastatic disease.
Currently, no clinical predictors of tumor growth or disease progression have been identified; although, the risk of developing progressive disease over the short term appears low. Clinical and molecular markers of disease progression are needed prior to offering active surveillance to otherwise acceptable surgical candidates.
Renal Tumors; Active Surveillance; Disease Progression
Pancreatic cystic neoplasms are being increasingly identified with the widespread use of advanced imaging techniques. In the absence of a good radiologic or pathologic test to preoperatively determine the dianosis, clinical characteristics might be helpful. The objectives of this analysis were to define the incidence and predictors of malignancy in pancreatic cysts.
Patients and Methods:
Patients with true pancreatic cysts who were treated at our institution were included. Patients with documented pseudocysts were excluded. Demographic data, clinical manifestations, radiological, surgical, and pathological records of those patients were reviewed.
Eighty-one patients had true pancreatic cyst. The mean age was 47 ± 15.5 years. There were 28.4% serous cystadenoma, 21% mucinous cystadenoma, 6.2% intraductal papillary tumors, 8.6% solid pseudopapillary tumors, 1.2% neuroendocrinal tumor, 3.7% ductal adenocarcinoma, and 30.9% mucinous cystadenocarcinoma. Malignancy was significantly associated with men (P = 0.04), older age (0.0001), cysts larger than 3 cm in diameter (P = 0.001), presence of solid component (P = 0.0001), and cyst wall thickening (P = 0.0001). The majority of patients with malignancy were symptomatic (26/28, 92.9%). The symptoms that correlated with malignancy included abdominal pain (P = 0.04) and weight loss (P = 0.0001). Surgical procedures were based on the location and extension of the lesion.
The most common pancreatic cysts were serous and mucinous cysts. These tumors were more common in females. Old age, male gender, large tumor, presence of solid component, wall thickness, and presence of symptoms may predict malignancy in the cyst.
Cystadenocarcinoma; cystadenoma; enucleation; pancreatic cyst; pseudocyst
Kidney cancer occurs in both a hereditary (inherited) and sporadic (non-inherited) form. It is estimated that almost a quarter of a million people in the USA are living with kidney cancer and their number increases with 51,000 diagnosed with the disease every year. In clinical practice, the response to treatment is monitored by manual measurements of tumor size, which are 2D, do not reflect the 3D geometry and enhancement of tumors, and show high intra- and inter-operator variability. We propose a computer-assisted radiology tool to assess renal tumors in contrast-enhanced CT for the management of tumor diagnoses and responses to new treatments. The algorithm employs anisotropic diffusion (for smoothing), a combination of fast-marching and geodesic level-sets (for segmentation), and a novel statistical refinement step to adapt to the shape of the lesions. It also quantifies the 3D size, volume and enhancement of the lesion and allows serial management over time. Tumors are robustly segmented and the comparison between manual and semi-automated quantifications shows disparity within the limits of inter-observer variability. The analysis of lesion enhancement for tumor classification shows great separation between cysts, von Hippel-Lindau syndrome lesions and hereditary papillary renal carcinomas (HPRC) with p-values inferior to 0.004. The results on temporal evaluation of tumors from serial scans illustrate the potential of the method to become an important tool for disease monitoring, drug trials and noninvasive clinical surveillance.
contrast-enhanced CT; kidney cancer; von Hippel-Lindau syndrome; hereditary papillary renal carcinoma; segmentation; quantification; classification; monitoring; level sets; computer-assisted radiology
The growth kinetics of untreated solid organ malignancies are not defined. Radiographic active surveillance (AS) of renal tumors in patient unfit or unwilling to undergo intervention provides an opportunity to quantitate the natural history of untreated localized tumors. Here we report the radiographic growth kinetics of renal neoplasms during a period of surveillance.
We identified patients with enhancing renal masses who were radiographically observed for at least 12 months. Clinical and pathological records were reviewed to determine tumor growth kinetics and clinical outcomes. Tumor growth kinetics were expressed in terms of absolute and relative linear and volumetric growth.
We identified 172 renal tumors in 154 patients under AS. Median tumor diameter and volume on presentation was 2.0 cm (mean 2.5, range 0.4 - 12.0) and 4.18 cm3 (mean 20.0, range 0.0033 – 904). Median duration of follow-up was 24 months (mean 31, range 12 – 156). A significant association between presenting tumor size and proportional growth was noted, with smaller tumors growing faster than larger tumors. 39% (68/173) of tumors underwent delayed intervention and 84% (57/68) were pathologically malignant. Progression to metastatic disease was noted in 1.3% (2/154) of patients.
We demonstrate the association between a tumor’s volume and subsequent growth with smaller tumors exhibiting significantly faster volumetric growth than larger tumors, consistent with Gompertzian kinetics. Surveillance of localized renal tumors is associated with a low rate of disease progression in the intermediate term and suggests potential over-treatment biases in select patients.
Active Surveillance; Growth Kinetics; Kidney Neoplasms
Patients with von Hippel-Lindau disease (VHL) commonly develop pancreatic cysts and neuroendocrine tumors (PNETs). Solid microcystic serous adenoma (SMSA), a rare tumor described in VHL patients, can be mistaken for PNET on imaging.
Clinical, pathologic and radiologic data were reviewed on VHL patients who underwent surgery for a pre-operative diagnosis of PNET since 1994 at one institution. Blinded to the pathological diagnoses, radiologists reassessed available imaging.
For 55 patients, 79 pancreatectomies were performed for presumed PNETs. Ten (18.2%) patients underwent 12 (15.2%) resections for tumors diagnosed as SMSA on final pathology. The average size of a SMSA leading to surgery was 3.6 ±0.4 cm. Four out of 11 SMSAs were still mistaken for PNETs when imaging was reassessed. Mean FDG-PET SUV was higher for 17 PNETs (12.1 ±1.2) compared to 6 SMSAs (4.2 ±0.5; p=0.002). The mean doubling time of SMSAs and PNETs was similar. Seven (15.2%) patients with pathologically-proven PNETs had malignant disease.
SMSAs can mimic PNETs on non-functional imaging; FDG-PET may help differentiate them. A high index of suspicion is needed to minimize operations performed for SMSA and to counsel VHL patients of their risks of undergoing surgery for a lesion with no known malignant potential.
Primary renal lymphoma is an uncommon variant of extranodal non-Hodgkin’s lymphoma. Manifestations are usually nonspecific hematuria, fever, flank pain, and renal insufficiency. Pathological data are scanty; few reports indicate it has a very poor prognosis. We describe a child with bilateral symmetrically palpable kidneys, low-grade pyrexia, and arthralgia. Clinically, diagnosis was missed partly due to the fact that bilateral large renal tumors commonly produce asymmetric renal swelling, renal dysfunction, and hematuria which were absent in this case and partly due to rarity of the condition. However, radiological investigations combined with renal histology helped in establishing diagnosis in the present case.
Extranodal lymphoma; normal renal function; symmetrical renal enlargement
Purpose: Tumor growth and progression requires multiple steps and genetic alterations. The molecular events that occur as tumors increase in size are unknown. Patients with von Hippel-Lindau (VHL) provide a unique opportunity to study molecular alterations during tumor growth as these patients develop multiple bilateral renal tumors. To better characterize biologic events associated with tumor growth, we evaluated the alterations in gene expression in large versus small renal tumors removed from the same kidney of the same individuals.
Experimental Design: We reviewed pathology reports from patients who underwent partial nephrectomies at the National Cancer Institute for multiple tumors. We identified 11 patients who fulfilled the following inclusion criteria: 1) The patient must have had a surgical resection of more than one solid tumor from the same kidney during the same operation; 2) Among the solid tumors at least one must have been greater than 3 cm in the largest dimension and at least one less than 2 cm; 3) the nuclear Furhman grade for both larger and smaller solid tumors was identical; 4) a portion of each tumor was procured and snap frozen after surgical removal; 5) Hematoxylin and eosin staining of the frozen sample confirmed clear cell carcinoma to be present in at least 80% of the section.
Affymetrix platform and protocol for gene expression arrays were used. RNA from the frozen large and small tumor samples was extracted using Trizol-Chlorophorm method. The RNA was then reverse transcribed, labeled, fragmented, and hybridized on to an Affymetrix U133 Plus 2.0 array that contains 54,000 probe sets representing 24,568 genes. Analysis included unsupervised clustering and chromosomal analysis. The paired t-test was performed to compare gene expression levels in small and large tumors. P<0.01 was considered statistically significant.
Results: Gene expression profiles were assessed for 22 tumors (11 patients). Upon unsupervised clustering the pairs with larger tumor volume difference clustered separately from pairs with smaller volume difference. Chromosomal analysis revealed few consistent changes other than reduced expression of chromosome 3p25 among all tumors. Paired t-test showed 860 differentially expressed genes in the T1b vs T1a group, a number far greater than expected due to chance alone. When analyzed by gene function, most differences were observed in genes involved in DNA replication and in cytokine signaling.
Conclusions: This study demonstrates that as tumors increase in size there is an increasing difference in gene expression. Unsupervised clustering analysis confirms that as the volume difference increases there are a distinct set of genes that are regulated either as a response to a tumor's growth or as an early event that causes the tumor to grow. While we did not observe chromosomal instability, we did note differences in expression of individual transcripts as tumors grew larger.
Renal cell carcinoma; tumor; size; microarray; kidney
The incidence of accidentally detected small renal tumors is increasing throughout the world. In this multi-institutional study performed in Korea, histopathological characteristics of contemporarily surgically removed renal tumors were reviewed with emphasis on tumor size.
Materials and Methods
Between January 1995 and May 2005, 1,702 patients with a mean age of 55 years underwent surgical treatment at 14 training hospitals in Korea for radiologically suspected malignant renal tumors. Clinicopathological factors and patient survival were analyzed.
Of the 1,702 tumors, 91.7% were malignant and 8.3% were benign. The percentage of benign tumors was significantly greater among those ≤ 4 cm (13.2%) than those > 4 cm (4.5%) (p < 0.001). Among renal cell carcinoma patients, the percentage of tumors ≤ classed as stage ≥ T3 was significantly less among tumors 4 cm (5.2%) than those > 4 cm (26.8%) (p < 0.001). The percentage of tumors classed as Fuhrman's nuclear grades ≥ 3 was also significantly less among tumors ≤ 4 cm (27.3%) than tumors > 4 cm (50.9%) (p < 0.001). The 5-year cancer-specific survival rate was 82.7%, and T stage (p < 0.001), N stage (p < 0.001), M stage (p = 0.025), and Fuhrman's nuclear (p < 0.001) grade were the only independent predictors of cancer-specific survival.
In renal tumors, small tumor size is prognostic for favorable postsurgical histopathologies such as benign tumors, low T stages, and low Fuhrman's nuclear grades. Our observations are expected to facilitate urologists to adopt function-preserving approach in the planning of surgery for small renal tumors with favorable predicted outcomes.
Kidney neoplasms; renal cell carcinoma; nephrectomy; surgical pathology
Accurate clinical staging of oral squamous cell cancer can be quite difficult to achieve especially if nodal involvement is identified. Radiologically-assisted clinical staging is more accurate and informs the clinician of loco-regional and distant metastasis.
In this study, we compared clinical TNM (cTNM) staging (not including ultrasonography) to pathological TNM (pTNM) staging in 245 patients presenting with carcinoma of the oral cavity and the oro-pharyngeal region. Tumour size differences and nodal involvement were highlighted. US reports of the neck were then added to the clinical staging and results compared.
Tumour size was clinically underestimated in 4 T1, 2 T2 and 2 T3 oral diseases. Also 20 patients that were reported as nodal disease free had histological proven N1 or N2 nodal involvement; while 3 patients with cTNM showing N1 disease had histologically proven N2 disease.
Overall the agreement between the 2 systems per 1 site was 86.6% (Kappa agreement = 0.80), per 2 sites 90.0% (Kappa agreement = 0.68) and per 3 sites 90.5% (Kappa agreement 0.62).
An accurate clinical staging is of an utmost importance. It is the corner stone in which the surgical team build the surgical treatment plan and decide whether an adjuvant therapy is required to deal with any possible problem that might arise. The failure to achieve an accurate staging may lead to incomplete surgical planning and hence unforeseen problems that may adversely affect the patient's survival.
Pathologic stage is the most accurate prognostic factor of renal cell carcinoma. We evaluated whether perirenal fat infiltration is a significant factor in tumors 7 cm or less in size.
Materials and Methods
We retrospectively reviewed the record of 164 cases of tumors 7 cm or less in size. We divided the patients into two groups according to the presence of perirenal fat infiltration (group A, pT1; group B, pT3a). We evaluated relationships, recurrence-free survival and disease-specific survival according to clinicopathologic parameters. Statistical differences were calculated by log-rank test.
A total 131 patients were included in group A, with a mean age of 55.8 years, average tumor size was 4.2 cm, and a mean follow-up period of 43 months. Group B included 33 patients, with a mean age of 55.9 years, an average tumor size of 4.1 cm, and a mean follow-up period of 38 months. There was no significant difference in disease-specific survival; however, recurrence-free survival showed significantly different between two groups (group A: 95.5%, group B: 84.4%).
In this study, perirenal fat infiltration proved to be an independent prognostic factor for predicting disease-free survival in patients with tumors of 7 cm or less in size. Therefore, as this study showed, the presence of perirenal fat infiltration requires stricter follow-up planning, even in small renal cell carcinoma.
Carcinoma; renal cell; adipose tissue; neoplasm invasiveness; prognosis