Thymomas are rare tumors of the mediastinum; a limited number of small studies have evaluated the outcomes in these patients. We identified 668 patients with thymoma from the Swedish Cancer Registry, and 2,719 population-based matched controls. We obtained information on autoimmunity from the nationwide inpatient/outpatient hospital discharge Registry. We constructed Kaplan-Meier curves for survival analysis, conditional regression and Cox proportional hazards models to evaluate the association between thymoma and autoimmune diseases, and standardized incidence ratios (SIRs) to evaluate the risk for second cancers following thymoma. Compared with controls, patients with benign or malignant thymoma had a poorer (p <0.001) 5-year (79%, 53% vs. 91%), 10-year (65%, 39% vs. 78%), and 20-year (43%, 18% vs. 55%) overall survival. For thymoma patients, younger age at diagnosis and being diagnosed in recent years were associated with a better survival. Compared with controls, thymoma patients were more likely to have an autoimmune disease at some point during their lives (32.7% vs. 2.4%, respectively, p<0.001), most frequently myasthenia gravis (24.5%), systemic lupus erythematosus (2.4%), and red cell aplasia (1.2%). Thymoma patients had 2-fold excess risk for second cancers compared with the general population, most notably: non-melanoma skin cancer (SIR=10.6, 95% confidence intervals (CI)=6.0–17.3), non-Hodgkin lymphoma (SIR=6.8, 95% CI=3.00–13.0), and cervical (SIR=6.9, 95% CI=1.4–20.1), endocrine (SIR=4.7, 95% CI=1.3–12.0), and prostate cancer (SIR=3.0, 95% CI=1.7–4.8). Despite the improved survival for thymoma patients over time, they have worse survival than controls. Thymoma patients are in need for follow-up to detect and manage autoimmune diseases and cancer.
thymoma; autoimmunity; second cancer
One half of cortical thymoma patients develop myasthenia gravis (MG), while 15% of MG patients have thymomas. MG is a neuromuscular junction disease caused in 85% of the cases by acetylcholine receptor (AChR) antibodies. Titin and ryanodine receptor (RyR) antibodies are found in 95% of thymoma MG and 50% of late-onset MG (MG onset ≥50 years), are associated with severe disease, and may predict thymoma MG outcome. Nonlimb symptom profile at MG onset with bulbar, ocular, neck, and respiratory symptoms should raise the suspicion about the presence of thymoma in MG. The presence of titin and RyR antibodies in an MG patient younger than 60 years strongly suggests a thymoma, while their absence at any age strongly excludes thymoma. Thymoma should be removed surgically. Prethymectomy plasmapheresis/iv-IgG should be considered before thymectomy. The pharmacological treatment does not differ from nonthymoma MG, except for tacrolimus which is an option in difficult thymoma and nonthymoma MG cases with RyR antibodies.
Myasthenia gravis (MG) is an autoantibody-mediated disorder affecting the neuromuscular junction causing characteristic fatigable muscle weakness. Though it can be associated with tumours of the thymus as well as thyroid disorders, it is rare for both to coexist. The exact prevalence of thyroid carcinoma in MG with thymoma is not known but only about a dozen cases have been reported in the literature. We report a case of a 38-year-old Myanmar lady who presented with weakness and breathlessness due to MG with neck swelling. On examination, she had fatigable proximal muscle weakness and thyroid enlargement with no obvious features of hyperthyroidism. Mediastinal widening and an enlarged thyroid gland were noted on her chest X-ray and chest CT. A subtotal thyroidectomy and thymectomy were done. The histology showed follicular carcinoma of the thyroid and benign thymoma. The majority of the reported cases of thyroid carcinoma in association with MG were papillary carcinoma. Follicular carcinoma thyroid associated with MG has not yet been reported in the literature.
myasthenia gravis; thymoma; follicular carcinoma of thyroid; thyroid carcinoma
Seventy four cases of thymoma were reclassified into three histological categories--cortical (30), medullary (9), and mixed (34) (the remaining patient had an intrathymic thymoma)--for an investigation of the relation between histological type, clinical behaviour, and long term prognosis. There were significant differences between the histological types in the frequency of myasthenia gravis and of the different tumour stages, the mean age of the patients, and prognosis. Myasthenia gravis occurred more commonly in patients with cortical (33%) and mixed thymoma (35%) than in patients with medullary thymoma (11%). Five, 10, 15, and 20 year actuarial survival was 100% for medullary thymoma; 85%, 76%, 65% and 65% respectively for mixed thymoma; and 52%, 45%, 45%, and 45% for cortical thymoma. Medullary thymoma is a benign tumour arising late in life and there was no mortality in this series after surgery alone. Cortical thymoma usually presented in middle age and must be regarded as malignant; mortality was 50% at five years despite a multidisciplinary approach, with surgery and postoperative radiotherapy in all patients and chemotherapy in selected cases. Mixed thymoma had a better prognosis than cortical thymoma, but must be regarded as potentially malignant. One third of the total patients had died by 10 years despite radical tumour resection.
A case of fulminant, fatal myocarditis occurring 10 days after resection of a benign medullary thymoma is described. A rare association between thymoma and giant cell myocarditis is recognised, but fulminant presentation so soon after removal of thymoma has not previously been reported.
The occurrence of red cell aplasia of the bone marrow and benign thymoma is a rare but well-defined syndrome. Data presented suggest the presence in the serum of a patient who had thymoma, of a humoral factor which may inhibit erythropoiesis. Further attempts should be made to clarify the association of thymoma and anerythroid anemia.
The human BCR-ABL oncogenes encoded by the Philadelphia chromosome (Ph) affect the pathogenesis of diverse types of leukemia and yet are rarely associated with T-lymphoid leukemia. To determine whether BCR-ABL kinases are inefficient in transforming T lymphocytes, BCR-ABL-expressing retroviruses were injected intrathymically into mice. Thymomas that expressed BCR-ABL kinase developed after a relatively long latent period. In most thymomas, deletion of 3' proviral sequences resulted in loss of tk-neo and occasionally caused expression of kinase-active carboxy-terminally truncated BCR-ABL oncoprotein. In contrast, deletion of 3' proviral sequences was not observed in thymomas induced with Abelson murine leukemia virus (A-MuLV). BCR-ABL viruses induced distinct patterns of disease and involved different thymocyte subsets than A-MuLV and Moloney murine leukemia virus (Mo-MuLV). While Mo-MuLV only induced Thy-1+ thymomas, v-abl- and BCR-ABL-induced thymomas often contained mixed populations of B220+ and Thy-1+ lymphocytes in the same tumor. In most v-abl and BCR-ABL tumors, Thy-1+ lymphoid cells expressed CD8 and a continuum of CD4 ranging from negative to positive. Conversely, Mo-MuLV thymomas contained distinct populations of CD4+ cells that were either CD8+ or CD8-. A-MuLV-transformed T-lymphoid cells did not express the CD3/T-cell receptor complex, while BCR-ABL tumors were CD3+. Thus, BCR-ABL viruses preferentially induce somewhat more differentiated T lymphocytes than are transformed by A-MuLV. Furthermore, rare B220+ lymphocytes may represent preferred v-abl and BCR-ABL transformation targets in the thymus.
Thymomas are typically benign tumors of thymic epithelium. Metastases to distal sites, particularly intracranial locations, are extremely rare. Herein, we present the third case of thymoma and the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.
A 41-year-old female patient presented with headaches, stuffy nose, and drooping of the right face. A magnetic resonance imaging scan revealed a complex, multilobulated mass centered upon the right cavernous sinus. The mass was removed via transsphenoidal surgery, and histopathological investigation confirmed the diagnosis of metastatic thymoma. A positron emission tomography-computed tomography scan demonstrated a large anterior mediastinal mass. A biopsy confirmed the diagnosis of invasive thymoma morphologically identical to the World Health Organization type B2 sellar region metastasis.
Although rare, thymomas can metastasize to the central nervous system. Our case is the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.
Cancer; immunohistochemistry; metastatic tumor; pathology; sellar metastases; thymoma
Autoimmune phenomena are more frequent in thymic epithelial tumors (TET) than in any other human tumor. Mysthenia gravis (MG) is by far the most common autoimmune disease in thymoma patients. MG is characterized by muscle weakness due to autoantibodies against the acetylcholine receptor (AChR), and CD4 +AChR-specific T cells play a pivotal role for the production of these autoantibodies. About 10% of MG patients have a thymoma and, interestingly, only such thymomas exhibit an MG association that maintains thymuslike
morphological and functional features with respect to the homing and differentiation of immature T cells. Since AChR protein is not expressed in thymomas, the specificity of the autoimmunity in thymoma-associated MG is thought to be determined by nonreceptor proteins with AChR epitopes. Such proteins are overexpressed in cortical-type MG-associated thymomas, and medullary thymomas express these proteins at barely detectable levels. Aside from this quantitative difference, the pathogenesis of anti-AChR autoimmunity might be qualitatively
different in these thymoma subtypes. Our findings suggest that an antigen-specific abnormal Tcell selection by cortical-type TET may contribute to the pathogenesis of paraneoplastic MG. In contrast, an abnormal (intratumorous) activation of autoreactive T cells may be operative in medullary thymomas.
Thymoma; acetylcholine receptor; titin; neurofilaments; T cells
Thymoma is a rare malignancy of unknown etiology. Based on cancer registry data, the overall incidence of thymoma in the U.S. is 0.13 per 100,000 person-years. Thymoma is exceedingly uncommon in children and young adults, rises in incidence in middle age, and peaks in the seventh decade of life. For unknown reasons, thymoma incidence is especially high among Asians and Pacific Islanders in the U.S. While several studies based at single treatment centers have suggested that thymoma patients have a broadly increased risk for other malignancies, follow up data from U.S. cancer registries support a more limited spectrum of cancer risk. In particular, people with thymoma have a subsequently elevated risk for developing B-cell non-Hodgkin lymphoma, consistent with an effect of immune disturbance arising from the thymoma or its treatment. Based on limited data, thymoma patients may also have an elevated risk for developing soft tissue sarcomas. While these descriptive epidemiologic data may yield clues to the etiology of thymoma, large multi-center case-control studies will be required to formally evaluate environmental and genetic risk factors.
Among human neoplasms thymomas are associated with highest frequency with paraneoplastic autoimmune diseases.
A case of a 42-year-old woman with paraneoplastic pemphigus as the first manifestation of thymoma is reported. Transsternal complete thymoma resection achieved pemphigus regression. The clinical correlations between pemphigus and thymoma are presented.
Our case report provides further evidence for the important role of autoantibodies in the pathogenesis of paraneoplastic skin diseases in thymoma patients. It also documents the improvement of the associated pemphigus after radical treatment of the thymoma.
A small proportion of thymoma patients without myasthenia gravis (MG) have been observed to develop MG after total removal of the thymoma. However, the underlying cause is not yet known due to the rarity of postoperative MG patients. We report a 39-year-old man in whom MG appeared after surgical removal of a thymoma. Computed tomography and magnetic resonance imaging showed no signs of recurrent or metastatic thymoma. Administration of pyridostigmine bromide resulted in the prompt improvement of myasthenic symptoms. Our observations indicate that postoperative follow-up care with monitoring of possible postoperative MG is necessary after resecting a thymoma.
Myasthenia gravis; Thymectomy; Thymoma
Thymic T cell development is characterized by sequential selection processes to ensure generation of a self-tolerant, immuncompetent mature T cell repertoire. Malfunction of any of these selection processes may potentially result in either immunodeficiency or autoimmunity. Myasthenia gravis (MG) is a typical autoimmune manifestation of thymic epithelial tumors (thymomas) and is related to the capacity of these tumors to generate and export mature T cells. Analysis of the factors that lead to autoimmunization in thymomas will help to understand the mechanisms that prevent MG under physiological conditions in humans. In a comparison of MG(+) and MG(-) thymomas, we could show that only thymomas capable of generating mature CD45RA+CD4+ T cells are associated with MG (p< 0.0001), while terminal thymopoiesis was abrogated in MG(-) thymomas. In particular, acquisition of the CD27+CD45RA+ phenotype appears to be a critical checkpoint of late T cell development in the human thymus and may play an important role in the prevention of autoimmunity. Moreover, MG(-) thymomas were virtually depleted of regulatory (CD4+CD25+) T cells (regT), while regT were readily detectable in MG(+) thymomas, albeit at significantly reduced numbers compared to control thymuses. Thus, in MG(+) thymoma patients, thymectomy apparently also results in removal of a regulatory T cell pool and may explain the frequent temporary postoperative deterioration of MG in these patients.
The histological and clinical features of 22 thymomas were reviewed. Immunohistochemical studies were performed using antibodies to cytokeratins (CAM 5.2 and S29) and to desmosomal protein. The heterogeneity of staining patterns seen in the epithelial cells supported the concept of separating thymomas into cortical, medullary, or mixed groups. Interdigitating cells were identified by antibody to S100 protein, and these varied in number between different tumours. Clustering of interdigitating reticulum cells occurred in association with foci of mature lymphocytes which were shown by staining of the leucocyte common antigen (CD45). The extent to which this occurred was used to assess the degree of medullary differentiation within the thymomas and this was correlated with the histological and clinical features. The lymphocyte population of six of the thymomas was studied using a range of antibodies to T and B cells; this showed the presence of B lymphocytes in thymomas.
Myasthenia gravis is a serious and debilitating disease associated with conduction defects occurring at the myoneural junction. About 15 per cent of the patients have associated tumors of the thymus and 80 per cent of the remaining patients show abnormalities of the thymus. Although a definite relationship between cause and effect has not been proved, thymectomy or radiotherapy of the thymus does seem to influence the disease.
Seven cases of myasthenia gravis in which radiation therapy was used at the University of California Medical Center are reported and compared with those described in the literature. It is concluded that patients whose disease is progressing and not well managed medically, and who have no evidence of thymoma, should be treated by irradiation—whether pre-operatively or as definitive treatment, depending on the result of irradiation. Those patients with evidence of thymoma should be irradiated before surgical procedure. Small tumors, or patients in whom surgical risk is increased, may be managed by radiation therapy alone.
Good syndrome is a rare cause of combined B- and T-cell immunodeficiency that occurs in association with a thymoma. Patients affected with Good syndrome have increased susceptibility to bacterial, fungal, viral, and opportunistic infections.
To describe 2 unusual cases of infections in patients with Good syndrome and review the literature.
Case 1 describes a 51-year-old woman with Good syndrome who presented with a 10-day history of diarrhea, nausea, and fevers. During her hospitalization she became pancytopenic and underwent a bone marrow biopsy and evaluation of her peripheral blood smear. Case 2 describes an 89-year-old man with Good syndrome who presented with a nonhealing leg ulcer, which underwent biopsy. A literature search through MEDLINE was performed. Keywords included Good syndrome, thymoma, hypogammaglobulinemia, immunodeficiency, and infection.
The peripheral blood smear in patient 1 showed ring-formed parasites in red blood cells suggestive of babesiosis. She began treatment with azithromycin, atovaquone, and doxycycline and recovered completely. Patient 2 underwent a biopsy of the foot. Immunohistochemical staining was positive for human herpesvirus 8 consistent with Kaposi sarcoma.
The concomitant occurrence of immunodeficiency and thymoma is known as Good syndrome. In contrast to other humoral immune defects, patients with this syndrome can develop opportunistic infections, and the prognosis appears less favorable compared with X-linked agammaglobulinemia or common variable immunodeficiency. Immunological investigations, including T-cell subsets, B cells, and quantitative immunoglobulins, should be considered part of the routine diagnostic evaluation in patients with a thymoma and recurrent infections.
The case of a 52-year-old woman with a past history of thymoma resection who presented with chronic diarrhea and generalized edema is the focal point of this article. A diagnosis of Giardia lamblia infection was established, which was complicated by protein-losing enteropathy and severely low serum protein level in a patient with no urinary protein loss and normal liver function. After anti-helmintic treatment, there was recovery from hypoalbuminemia, though immunoglobulins persisted at low serum levels leading to the hypothesis of an immune system disorder. Good’s syndrome is a rare cause of immunodeficiency characterized by the association of hypogammaglobulinemia and thymoma. This primary immune disorder may be complicated by severe infectious diarrhea secondary to disabled humoral and cellular immune response. This is the first description in the literature of an adult patient with an immunodeficiency syndrome who presented with protein-losing enteropathy secondary to giardiasis.
Chronic diarrhea; Giardiasis; Protein-losing enteropathy; Immunodeficiency
Paraneoplastic retinopathy is caused by the cross-reaction of neoplasm-directed autoantibodies against retinal antigens and results in retinal damage. Paraneoplastic vitelliform retinopathy, a presumed paraneoplastic retinopathy with features of atypical melanoma-associated retinopathy, has recently been reported in patients with metastatic melanoma. Ocular ultrastructure and its autoantibody localization of paraneoplastic vitelliform retinopathy are still indefinable. This is the first report of anti-transient receptor potential M1 antibody directly against human retinal bipolar dendritic tips in a melanoma patient with paraneoplastic vitelliform retinopathy.
We present a pair of postmortem eyes of an 80-year-old male with metastatic cutaneous melanoma, who developed paraneoplastic vitelliform retinopathy. The autopsied eyes were examined with light microscopy, immunohistochemistry, and transmission electron microscopy. Microscopically, the inner nuclear layer and outer plexiform layer were the most affected retinal structures, with local thinning. The lesions extended to the outer nuclear layer, resulting in focal retinal degeneration, edema, and atrophy. No active inflammation or melanoma cells were observed. Immunohistochemistry showed tightly compact bipolar cell nuclei (protein kinase C alpha/calbindin positive) with blur/loss of ON bipolar cell dendritic tips (transient receptor potential M1 positive) in diffusely condensed outer plexiform layer. The metastatic melanoma cells in his lung also showed immunoreactivity against transient receptor potential M1 antibody. Transmission electron microscopy illustrated degenerated inner nuclear layer with disintegration of cells and loss of cytoplasmic organelles. These cells contained many lysosomal and autophagous bodies and damaged mitochondria. Their nuclei appeared pyknotic and fragmentary. The synapses in the outer plexiform layer were extensively degenerated and replaced with empty vacuoles and disintegrated organelles.
This case provides a convincing histological evidence of melanoma-associated autoantibodies directly against transient receptor potential M1 channels that target the ON bipolar cell structures in the inner nuclear and outer plexiform layers in paraneoplastic vitelliform retinopathy.
Paraneoplastic vitelliform retinopathy; Autoimmune retinopathy; Transient receptor potential channel; Bipolar cell; Melanoma-associated retinopathy; Autoantibody
Although rare, thymoma is the most common tumour of the anterior mediastinum. In an effort to assess the clinical and pathologic characteristics of this tumour and to determine whether clinicopathologic stage or histopathologic classification correlates with clinical outcome, in the Department of Pathology and the Department of Surgery at the University of Saskatchewan we reviewed all cases of thymoma registered in the province of Saskatchewan using the database of the Saskatchewan Cancer Centre.
In 65 patients with a diagnosis of thymoma or thymic carcinoma identified from the Saskatchewan Cancer Centre database between Jan. 1, 1960, and Dec. 31, 2000, we studied the presentation, diagnostic investigations, therapeutic interventions, tumour size, postoperative course, clinical stage, histopathologic classification, disease recurrence and mortality.
Of the 65 patients, 17 (26%) were asymptomatic and 11 (17%) had symptoms consistent with myasthenia gravis. Surgical resection is most commonly performed through a median sternotomy and frequently requires en bloc resection of one or more adjacent structures. The overall survival of patients with thymoma was found to correlate with the clinical stage as described by Masaoka and colleagues and with complete tumour resection. A trend to clinicopathologic correlation was observed when applying the histologic classification systems of Suster and Moran and the World Health Organisation, but this trend was not statistically significant.
Thymoma is a rare tumour with a variable clinical presentation. Clinical outcome correlates with clinical stage and the ability to achieve complete tumour resection.
Paraneoplastic retinopathy (PR), including cancer-associated retinopathy (CAR) and melanoma-associated retinopathy (MAR), is a progressive retinal disease caused by antibodies generated against neoplasms not associated with the eye. While several autoantibodies against retinal antigens have been identified, there has been no known autoantibody reacting specifically against bipolar cell antigens in the sera of patients with PR. We previously reported that the transient receptor potential cation channel, subfamily M, member 1 (TRPM1) is specifically expressed in retinal ON bipolar cells and functions as a component of ON bipolar cell transduction channels. In addition, this and other groups have reported that human TRPM1 mutations are associated with the complete form of congenital stationary night blindness. The purpose of the current study is to investigate whether there are autoantibodies against TRPM1 in the sera of PR patients exhibiting ON bipolar cell dysfunction.
We performed Western blot analysis to identify an autoantibody against TRPM1 in the serum of a patient with lung CAR. The electroretinograms of this patient showed a severely reduced ON response with normal OFF response, indicating that the defect is in the signal transmission between photoreceptors and ON bipolar cells. We also investigated the sera of 26 patients with MAR for autoantibodies against TRPM1 because MAR patients are known to exhibit retinal ON bipolar cell dysfunction. Two of the patients were found to have autoantibodies against TRPM1 in their sera.
Our study reveals TRPM1 to be one of the autoantigens targeted by autoantibodies in at least some patients with CAR or MAR associated with retinal ON bipolar cell dysfunction.
Molecular pathology of thymomas is poorly understood. Genomic aberrations are frequently identified in tumors but no extensive sequencing has been reported in thymomas. Here we present the first comprehensive view of a B3 thymoma at whole genome and transcriptome levels. A 55-year-old Caucasian female underwent complete resection of a stage IVA B3 thymoma. RNA and DNA were extracted from a snap frozen tumor sample with a fraction of cancer cells over 80%. We performed array comparative genomic hybridization using Agilent platform, transcriptome sequencing using HiSeq 2000 (Illumina) and whole genome sequencing using Complete Genomics Inc platform. Whole genome sequencing determined, in tumor and normal, the sequence of both alleles in more than 95% of the reference genome (NCBI Build 37). Copy number (CN) aberrations were comparable with those previously described for B3 thymomas, with CN gain of chromosome 1q, 5, 7 and X and CN loss of 3p, 6, 11q42.2-qter and q13. One translocation t(11;X) was identified by whole genome sequencing and confirmed by PCR and Sanger sequencing. Ten single nucleotide variations (SNVs) and 2 insertion/deletions (INDELs) were identified; these mutations resulted in non-synonymous amino acid changes or affected splicing sites. The lack of common cancer-associated mutations in this patient suggests that thymomas may evolve through mechanisms distinctive from other tumor types, and supports the rationale for additional high-throughput sequencing screens to better understand the somatic genetic architecture of thymoma.
The management of locally advanced inoperable malignant thymoma is difficult as there are no large randomized clinical trial data to guide treatment. However various case series have shown that malignant thymoma is often a chemosensitive disease. Cisplatin-based chemotherapy has been the gold-standard in the management of these patients. However when thymic cancers are complicated by paraneoplastic syndromes that damage kidney and neurological function, cisplatin use is often contraindicated.
We report a case of a 37 year old man with locally advanced malignant thymoma complicated by significant nephrotic syndrome and renal impairment. He responded to a novel combination of carboplatin, epirubicin and cyclophosphamide chemotherapy used as first line therapy.
The treatment with chemotherapy of locally advanced malignant thymoma complicated by nephrotic syndrome and renal impairment is difficult due to the increase of toxicity. In this case, a novel chemotherapy combination with lesser toxicity was used successfully. In addition this chemotherapy combination did not impede the later use of conventional cisplatin-based chemotherapy. Therefore we suggest a course of carboplatin-based chemotherapy for locally advanced malignant thymoma in patients who are unsuitable for cisplatin.
Good's syndrome is extremely rare. This adult-onset condition is characterized by a thymoma with immunodeficiency, low B- and T-cell counts, and hypo-gammaglobulinemia. The initial clinical presentation is either a mass-lesion thymoma or a recurrent infection. Patients with Good's syndrome are very susceptible to infections; common respiratory and opportunistic infections can be life-threatening. There are no reports of granulomatous lung disease in patients with Good's syndrome, although it has been observed in patients with common variable immunodeficiency, of which Good's syndrome is a subset. We describe a 53-year-old male thymoma patient who presented with respiratory symptoms caused by granulomatous lung disease and an opportunistic infection. He died of uncontrolled fungal infection despite repeated intravenous immunoglobulin and supportive care. Clinicians should look for evidence of immunologic dysfunction in thymoma patients presenting with severe recurrent infections, especially opportunistic infections.
Thymoma, Immunodeficiency; Opportunistic infection
We report here a case of thymoma simultaneously associated with undifferentiated pleomorphic sarcoma. A 45-year-old male presented with axillary lump. Radiographic studies showed a mediastinal mass. On fine needle aspiration cytology and histopathological examination, a diagnosis of thymoma with coexisting undifferentiated pleomorphic sarcoma was made. Although thymomas are associated with many extrathymic malignancies, it's association with undifferentiated pleomorphic sarcoma is rare. This case is being reported on to reinforce that clinicians should bear in mind the possibility of extrathymic malignancies in patients with thymomas.
Thymomas are rare, slow-growing tumours that present in a variety of ways such as incidental findings on chest radiographs following symptoms of cough and dyspnoea. Thymomas may also present with symptoms due to intrathoracic spread such as superior vena cava obstruction, or with symptoms of an associated paraneoplastic disorder. Such paraneoplastic disorders are typified by the generation of autoantibodies directed against a variety of self antigens including myasthenia gravis, neuromyotonia, and hypogammaglobulinaemia.
Significant hypothermia in association with thymoma has been described previously in one published case report. The basis for hypothermia in that case was not clear, but was postulated to relate to abnormal central thermal regulation and was resolved completely following treatment with intravenous gammablobulin, thus suggesting an autoimmune aetiology.
We present the case of an 88-year-old man with Type A thymoma and persistent hypothermia. An extensive investigation of the hypothermia revealed no aetiology other than the thymoma itself. Symptoms of hypothermia were treated effectively with passive and active external rewarming. The patient's dyspnoea was much improved by intercostal drainage of a left-sided pleural effusion and talc pleurodesis. He was not offered definitive treatment for the thymoma in view of its relatively favourable prognosis, and because his symptoms were well controlled at the time of discharge.
We suggest that the possibility of thymoma be investigated once the more common causes of hypothermia have been excluded in an appropriate clinical context. To the best of our knowledge, this is only the second published case report describing such an association.