PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (846331)

Clipboard (0)
None

Related Articles

1.  Expression of bone morphogenic protein in sinonasal inverted papilloma with new bone formation 
Allergy & Rhinology  2011;2(1):16-20.
Inverted papilloma (IP) is a common benign tumor in the nose and sinus. Osteogenesis in sinonasal IP is extremely rare; to date, only five cases of IP with new bone formation appear in the literature. In addition, the mechanism of osteogenesis in IP remains unclear. Here, we describe three cases of IP with new bone formation and an investigation into a possible role for bone morphogenic protein (BMP) in osteogenesis. Of three patients with sinonasal IP with new bone formation, two were treated by endoscopic sinus surgery and one was followed up with watchful waiting. Tumor tissues were subjected to immunohistochemistry to detect BMP expression. The patients were successfully treated surgically and showed no evidence of recurrence postoperatively. Follow-up examination is ongoing. Immunohistochemically, the tumors expressed BMP-4 but not BMP-2 or BMP-7. ESS could be successfully used to achieve complete removal of the sinonasal IPs with new bone formation. BMP-4 might be associated with new bone formation in the tumor.
doi:10.2500/ar.2011.2.0004
PMCID: PMC3390124  PMID: 22852110
Bone formation; bone morphogenic protein; endoscopic sinus surgery; inverted papilloma; sinonasal
2.  Clinicopathological and Immunohistochemical Characterisation of Gastric Schwannomas in 29 Cases 
Schwannomas are tumors arising from the nervous system that also occur infrequently in the gastrointestinal tract, most commonly in the stomach. This report characterizes 29 patients with benign or malignant gastric schwannomas. Surgical data and clinical follow-up information were available for 28 cases with a median postoperative duration of 57 months. Clinicopathological and immunohistochemical characteristics of benign and malignant schwannomas were analysed. Four cases (13.7%) were histologically diagnosed with malignant schwannoma. All tumors were positive for S-100 and CD56 proteins, displaying a diffuse staining pattern. Vimentin was expressed in 100% cases and all schwannomas were negative for smooth muscle actin, c-kit, and HMB-45. A significant difference was observed between the group of benign and malignant schwannomas as regards recurrences and metastasis after complete resection (P = 0.015). The survival time of patients with benign schwannomas was longer than the malignant group (P = 0.013), so gastric malignant schwannomas have a potential for recurrence and metastasis, with subsequently short survival. Complete resection with an attempt to remove all tumor tissue with negative margins is of paramount importance in the management of gastric schwannomas, particularly when they turn out to be malignant.
doi:10.1155/2014/202960
PMCID: PMC3942198  PMID: 24688535
3.  Intraosseous schwannoma of the mandible 
Schwannomas (neurilemmomas) are slow-growing, benign neoplasms derived from schwann cells, the sheath cells that cover myelinated nerve fibers. These tumors most commonly arise in the soft tissues of the head and neck, as well as on the flexor surfaces of the upper and lower extremities. Intraoral lesions are uncommon, however, and intraosseous schwannomas are even rarer. In the Mayo Clinic series of 11,087 primary bone tumors, 14 cases of intraosseous schwannoma were identified, accounting for less than 1% of these benign primary bone tumors. The most common site of occurrence is the mandible, a characteristic traditionally attributed to the long intraosseous path of the inferior alveolar nerve. In this article, we describe an additional case occurring in the mandible of a 15-year-old boy.
doi:10.4103/0973-029X.99094
PMCID: PMC3424953  PMID: 22923909
Intraosseous schwannoma; mandible; neurilemmoma
4.  Expression of noggin, an antagonist of bone morphogenetic protein, in schwannoma: A possible mechanism 
Oncology Letters  2014;8(1):111-116.
Schwannoma is a benign peripheral nerve sheath tumor derived from Schwann cells. Bone scalloping, including spinal foramen enlargement, develops when the tumor is located adjacent to a bone and is a characteristic radiological feature. In the present study, to investigate the pathomechanism of bone resorption, the expression of noggin (a potent antagonist of bone morphogenetic protein) was analyzed in schwannoma tissues and compared with that observed in other soft tissue tumors. Quantitative polymerase chain reaction analysis revealed that the mRNA levels of noggin in schwannomas were significantly increased compared with the levels in other tumors. The gene product of noggin was only detected in a subset of schwannomas using immunohistochemistry and western blot analysis. Furthermore, the tissue extract from a noggin-producing schwannoma was found to inhibit osteoblastic differentiation in MC3T3 mouse osteoblastic cells in a dose-dependent manner. These findings indicate that bone scalloping in radiology may be induced by schwannoma-secreted noggin. In addition, noggin may have potential as a novel molecular and diagnostic marker for identifying certain types of schwannoma.
doi:10.3892/ol.2014.2138
PMCID: PMC4063616  PMID: 24959229
schwannoma; bone scalloping; noggin; bone morphogenetic protein
5.  A Cervical Vagal Schwannoma Mimicking a Parathyroid Cyst 
Cervical vagal schwannomas with cystic degeneration changes are extremely rare. These tumors are typically benign and slow growing. A 44-year-old woman underwent complete resection of a tumor measuring 4×3.5 cm in the right neck using the endoscopic approach, instead of the conventional transcervical approach. We applied the new scarless neck surgery technique with an endoscopic unilateral axillo-breast approach. The tumor originated from the right vagus nerve, and was confirmed to be a vagal schwannoma pathologically. The patient has been followed up for 18 months postoperatively with no evidence of tumor recurrence or neurological deficit. We report an extremely rare vagal schwannoma with cystic degeneration that was removed by an endoscopic approach, along with a review of the relevant literature.
doi:10.3342/ceo.2014.7.2.153
PMCID: PMC4050091  PMID: 24917916
Cervical vagal schwannoma; Unilateral axillo-breast approach
6.  A case of a massive mandibular schwannoma 
Schwannoma, a benign nerve sheath tumor is relatively rare in occurrence and even rarer in sites, such as jaw bones. There are only 45 reported cases of intraosseous schwannoma of the jaws reported in the literature. We report a rare case of mandibular schwannoma in a 50-year-old Indian male. The clinical features resembled that of a residual cyst, fibro-osseous lesion or an odontogenic tumor/cyst. Radiological differential diagnoses of ameloblastoma or odontogenic keratocyst was made based on the findings of the orthopantomogram. The lesion was examined histopathologically and a final diagnosis of schwannoma arising from the inferior alveolar nerve was made. The aim of this report is to add information to the existing sparse literature on intraosseous schwannomas of the jaw.
doi:10.4103/0976-3147.80108
PMCID: PMC3122997  PMID: 21716830
Intraosseous; mandible; schwannoma
7.  Schwannoma of the rectum: A case report and literature review 
Schwannoma is a tumor originating from the Schwann cells. Gastrointestinal schwannomas are uncommon stromal tumors of the intestinal tract and, in particular, rectal schwannomas are extremely rare. In fact, it is well established that schwannomas appear more frequently in the stomach and in the small intestine, while location in the colon or in the rectum is uncommon. Reading the literature, only few cases of rectal schwannoma have been reported. Their diagnosis is confirmed by the immunohistochemical panel (S-100 protein). When these tumors are located in the colon and in the rectum, radical excision with wide margins is mandatory, due to their tendency to recur locally or become malignant, if left untreated. In the present study, we describe a case of a rectal schwannoma occured in a 72-year-old man, presented as a small polypoid lesion, which was successfully removed in toto by hot-biopsy, during the same endoscopy, due to the dimensons. No recurrence of the lesion was observed after 6 mo of follow-up.
doi:10.12998/wjcc.v1.i1.49
PMCID: PMC3845929  PMID: 24303463
Rectum; Schwannoma; Immunohistochemistry; S-100 protein; Treatment
8.  Primary hepatic benign schwannoma 
Schwannoma is predominantly a benign neoplasm of the Schwann cells in the neural sheath of the peripheral nerves. Occurrence of schwannoma in parenchymatous organs, such as liver, is extremely rare. A 64-year-old man without neurofibromatosis was observed to have a space-occupying lesion of 23mm diameter in the liver during follow-up examination for a previously resected gastrointestinal stromal tumor (GIST) in the small intestine. He underwent lateral segmentectomy of the liver under a provisional diagnosis of hepatic metastatic recurrence of the GIST. Histological examination confirmed the diagnosis of a benign schwannoma, confirmed by characteristic pathological findings and positive immunoreactions with the neurogenic marker S-100 protein, but negative for c-kit, or CD34. The tumor was the smallest among the reported cases. When the primary hepatic schwannoma is small in size, preoperative clinical diagnosis is difficult. Therefore, this disease should be listed as differential diagnosis for liver tumor with clinically benign characteristics.
doi:10.4240/wjgs.v4.i3.73
PMCID: PMC3332224  PMID: 22530081
Liver; Schwannoma; Benign liver tumor
9.  Ancient Schwannoma of the hard palate. An uncommon case report and review 
Schwannoma or neurilemmoma is an infrequent benign tumor in the oral cavity that originates from the Schwann cells on the neural sheath of the peripheral nerves. Schwannomas are frequently located in the soft tissues of head and neck region, but only a 1 to 12% of them are located in the oral cavity. Some histological variants of schwannoma have been described including the cellular, plexiform, epithelioid, ancient, and melanocytic types. The “ancient schwannoma” is an uncommon variant of this tumor that shows specific histological characteristics, and is rare in the oral cavity with less than 15 cases described on the literature. Most of them were located in the tongue or in the floor of the mouth, being the hard palate an extremely rare localization. We present a new clinical case of an ancient schwannoma with a long time of evolution, arising from the nasopalatine nerve, and located in the hard palate of a 35 year old female. We also review the main clinical and histological characteristics of this pathology.
Key words:Ancient schwannoma, neurilemmoma, palate, schwannoma.
doi:10.4317/jced.50950
PMCID: PMC3892226  PMID: 24455054
10.  Bowel mesentery (meso-appendix) microcystic/reticular schwannoma: Case report and literature review 
Microcystic/reticular schwannoma is a recently described variant of schwannoma with a predilection for the gastrointestinal tract. Due to overlapping features with other tumors, unawareness of this tumor type may lead to diagnostic and therapeutic pitfalls. We here report a case of microcystic/reticular schwannoma arising in the meso-appendix of a 43-year-old woman. The tumor was incidentally discovered by computed tomography scan for unrelated reasons. A laparoscopic operation was performed shortly after admission. Histological examination revealed a circumscribed tumor with a striking microcystic and cribriform architecture. Immunohistochemically, the tumor cells were diffusely positive for S100 protein, glial fibrillary acid protein and protein gene product 9.5, which were consistent with a peripheral nerve sheath tumor. The patient remains well with no signs of recurrence at a 10-mo follow-up. To our knowledge, this is the first case of microcystic/reticular schwannoma arising in the meso-appendix. Albeit very rare, microcystic/reticular schwannoma should be included in the differential diagnosis of appendiceal tumors.
doi:10.3748/wjg.v20.i5.1371
PMCID: PMC3921522  PMID: 24574814
Laparoscopy; Schwannoma; Appendiceal neoplasms; Immunohistochemistry; Differential diagnosis; Gastrointestinal tract
11.  Atypical presentations of retroperitoneal giant schwannomas 
Clinics and Practice  2011;1(3):e47.
Schwannomas are usually benign rare tumors that originating from Schwann cells of peripheral nerve sheaths. Presentation is generally varied and changed in a non-specific range from abdominal mass, flank pain to incidental findings. Herein we report 2 cases of retroperitoneal giant schwannomas with different clinical presentations, of whom one presented with vague abdominal pain, palpable abdominal mass for 4 years, swelling and bilateral hydronephrosis that caused by giant abdominal mass; the other one presented with right flank pain, rectal hemorrhage and lower extremities edema. Two patients were treated by complete surgical excision of masses. The histological and immunohistochemical diagnosis was reported as benign schwannoma. Both of patients are doing well and had no recurrence in 9 years and 28 months follow-up, respectively.
doi:10.4081/cp.2011.e47
PMCID: PMC3981357  PMID: 24765308
schwannoma; retroperiton; diagnosis; treatment; giant.
12.  Breast schwannoma in a patient with diffuse large B-cell lymphoma: a case report 
Introduction
Schwannomas are mostly benign tumors arising from Schwann cells of the nerve sheaths. Breast schwannomas are very rare and account for only 2.6% of cases. As far as we know this is the first reported case of breast schwannoma discovered in a patient with diffuse large B-cell lymphoma. The breast schwannoma was evaluated with positron emission tomography and it exhibited moderate 18F-fluorodeoxyglucose uptake.
Case presentation
We present the case of a breast schwannoma in a 63-year-old Caucasian woman who was diagnosed with diffuse large B-cell lymphoma.
Conclusion
Imaging modalities including positron emission tomography-computed tomography failed to distinguish breast schwannoma from diffuse large B-cell lymphoma involvement of the breast.
doi:10.1186/1752-1947-6-423
PMCID: PMC3571884  PMID: 23244369
Breast; Diffuse large B-cell lymphoma; Positron emission tomography-computed tomography; Schwannoma
13.  Schwannoma of the eyelid: Apropos of two cases 
Indian Journal of Ophthalmology  2009;57(4):318-320.
Schwannoma, also referred to as neurilemmoma, is a benign tumor of peripheral nerve arising from Schwann cells that form the neural sheath. Schwannoma of ophthalmic interest is rare although it has been reported in relation with the orbit, and less frequently with the uveal tract and conjunctiva. Isolated eyelid schwannoma is extremely uncommon. Up until now, only eight cases have been reported in literature. Herein, we report two cases of eyelid schwannoma.
doi:10.4103/0301-4738.53063
PMCID: PMC2712707  PMID: 19574706
Benign tumor; eyelid; histopathology; schwannoma
14.  Giant presacral schwannoma presenting with constipation: a case report 
Introduction
Schwannoma, otherwise known as a neurilemmoma, is a tumor arising from peripheral nerve sheaths. Although commonly noted in association with the eighth cranial nerve as intracranial acoustic neuroma, cases of schwannoma arising in other locations have been reported in the literature. These tumors usually cause symptoms as a result of their mass effect and, since they are benign, encapsulated and non-invasive tumors, complete surgical excision is considered curative.
Case presentation
We report the case of a 46-year-old Sri Lankan man who presented to our facility with recent onset of difficulty evacuating his bowels. He was noted to have a giant presacral schwannoma on magnetic resonance imaging scan. The mass was surgically excised with improvement of our patient’s symptoms. A subsequent histopathological examination confirmed the presence of a benign schwannoma.
Conclusions
Although schwannomas commonly occur in the extremities, a rare case of occurrence in the pelvis is reported here. Due to the limited space in the pelvis, the local mass effect may be the presenting feature of such a lesion and surgical excision is curative.
doi:10.1186/1752-1947-6-285
PMCID: PMC3443643  PMID: 22963756
15.  Dorsal dumb-bell melanotic schwannoma operated on by posterior and anterior approach: case report and a review of the literature 
European Spine Journal  2006;15(Suppl 5):664-669.
The schwannomas are benign tumors originating from Schwann cells which constitute the nerve sheath. The dorsal pigmented type of schwannomas is relatively rare (Goldstein in Am J Med Genet 86:62–65, 2004; Kurtkaya-Yapicier in Histol Histopathol 18(3):925–934, 2003). There are two distinct types of melanotic schwannoma: the sporadic melanotic schwannomas and the psammomatous melanotic schwannomas of Carney complex. We report a case of a patient harboring a right dorsal dumb-bell melanotic schwannoma and left adrenal mass. The patient underwent a surgical procedure for en bloc total removal of the mass by a posterior and anterior approach. Histopathological examination revealed the diagnosis of melanotic schwannoma. At present, we have no reliable marker of histopathological malignancy of melanotic schwannoma so the follow-up period ought to continue for a period of more than 5 years. As the total removal of the melanotic neurinomas is mandatory to prevent possible malignant transformation of the tumor recurrence or regrowth, we believe that the posterior and trans-thoracic approach are the most suitable one for the dorsal dumb-bell schwannoma.
doi:10.1007/s00586-006-0205-x
PMCID: PMC1602204  PMID: 16947016
Dorsal dumb-bell melanotic schwannoma; Thoracic nerve sheath tumor; Spinal tumor; Carney syndrome
16.  Dorsal dumb-bell melanotic schwannoma operated on by posterior and anterior approach: case report and a review of the literature 
European Spine Journal  2006;15(Suppl 17):664-669.
The schwannomas are benign tumors originating from Schwann cells which constitute the nerve sheath. The dorsal pigmented type of schwannomas is relatively rare (Goldstein in Am J Med Genet 86:62–65, 2004; Kurtkaya-Yapicier in Histol Histopathol 18(3):925–934, 2003). There are two distinct types of melanotic schwannoma: the sporadic melanotic schwannomas and the psammomatous melanotic schwannomas of Carney complex. We report a case of a patient harboring a right dorsal dumb-bell melanotic schwannoma and left adrenal mass. The patient underwent a surgical procedure for en bloc total removal of the mass by a posterior and anterior approach. Histopathological examination revealed the diagnosis of melanotic schwannoma. At present, we have no reliable marker of histopathological malignancy of melanotic schwannoma so the follow-up period ought to continue for a period of more than 5 years. As the total removal of the melanotic neurinomas is mandatory to prevent possible malignant transformation of the tumor recurrence or regrowth, we believe that the posterior and trans-thoracic approach are the most suitable one for the dorsal dumb-bell schwannoma.
doi:10.1007/s00586-006-0205-x
PMCID: PMC1602204  PMID: 16947016
Dorsal dumb-bell melanotic schwannoma; Thoracic nerve sheath tumor; Spinal tumor; Carney syndrome
17.  Orbital Cystic Schwannoma Originating from the Frontal Nerve 
Schwannomas of the orbit are very rare benign neoplasms. Intraorbital cystic schwannomas originating from the frontal nerve are even rarer, with only 1 case reported to date. This is most likely due to the fact that, in most cases, the origin of the orbital schwannoma cannot be identified intraoperatively. The nerve origin is usually speculated from histological examination of the specimen and the postoperative neurological deficits of the patient. Here, we present the case of a 65-year-old woman with a one-month history of exophthalmos, whose orbital cystic lesion was completely removed by microsurgical transcranial operation. Intraoperatively, the continuity between the tumor and frontal nerve was seen macroscopically, leading us to confirm the frontal nerve as an origin of the tumor, which was consistent with the postoperative neurological findings. The diagnosis of the tumor was established as schwannoma from the histological examination. As a differential diagnosis of the orbital cystic lesions, the possibility of schwannomas should be kept in mind.
doi:10.1155/2012/604574
PMCID: PMC3540697  PMID: 23320224
18.  Laryngeal schwannoma excised under a microlaryngoscope without tracheotomy: A case report 
Schwannomas are benign encapsulated tumors arising from Schwann cells in the peripheral nervous system. Between 25 and 45% of schwannomas occur in the head and neck region. Schwannomas of the larynx are extremely rare with an incidence of 0.1–1.5% in all benign laryngeal tumors. Laryngeal schwannomas usually occur in females aged between their 4th and 5th decades. The most successful curative method is surgical resection. When selecting the surgical method, the size and location of the tumor, as well as the requests of the patient, should be considered. The present case report describes a 29-year-old female patient with symptoms of hoarseness and dyspnea on exertion. Through endoscopic biopsy, histopathology revealed a schwannoma. Considering the symptoms, age and preferences of the patient, the method of trans-oral microlaryngoscopic excision without tracheotomy was used to excise the tumor located in the aryepiglottic fold. Results from a short-term follow-up showed the postoperative result to be satisfactory.
doi:10.3892/etm.2014.1528
PMCID: PMC3964928  PMID: 24669270
laryngeal schwannoma; magnetic resonance imaging; surgical treatment
19.  Scrotal extratesticular schwannoma: a case report and review of the literature 
BMC Urology  2014;14:32.
Background
Schwannomas are tumours arising from Schwann cells, which sheath the peripheral nerves. Here, we report a rare case of left intrascrotal, extratesticular schwannoma. Although rare, scrotal localisation of schwannomas has been reported in male children, adult men, and elderly men. They are usually asymptomatic and are characterised by slow growth. Patients generally present with an intrascrotal mass that is not associated with pain or other clinical signs, and such cases are self-reported by most patients. Imaging modalities (such as ultrasonography, computed tomography, and magnetic resonance imaging) can be used to determine tumour size, exact localisation, and extension. However, the imaging findings of schwannoma are non-specific. Therefore, only complete surgical excision can result in diagnosis, based on histological and immunohistochemical analyses. If the tumour is not entirely removed, recurrences may develop, and, although malignant change is rare, this may occur, especially in patients with a long history of an untreated lesion. Thus, follow up examinations with clinical and imaging studies are recommended for scrotal schwannomas.
Case presentation
A 52-year-old man presented with a 3-year history of asymptomatic scrotal swelling. Physical examination revealed a palpable, painless, soft mass in the left hemiscrotum. After surgical removal of the mass, its histological features indicated schwannoma.
Conclusions
Schwannoma should be considered in cases of masses that are intrascrotal but extratesticular. Ultrasonography provides the best method of confirming the paratesticular localisation of the tumour, before surgical removal allows histopathological investigation and definitive diagnosis. Surgery is the standard therapeutic approach. To prevent recurrence, particular care should be taken to ensure complete excision. This case report includes a review of the literature on scrotal schwannomas.
doi:10.1186/1471-2490-14-32
PMCID: PMC4030735  PMID: 24776090
Scrotal schwannoma; Diagnosis; Histopathology
20.  Schwannoma of the nose and paranasal sinuses 
Sckhwannoma is a benign tumor arising from the Schwann cells of nerve sheath.Through they arise more commonly in the head and neck than other regions, a through search in the liturature including medline revealed only about 47 reported cases of schwannoma in the paranasal sinuses of which the maxillary sinus involvement is more common. We report three cases of schwannoma arising from unusual sites in the paranasal sinuses with different modes of presttation each requiring a specific approach for surgical excision Transnasal endoscopic approach in combination with vonventional approaches is of immense value in the surgical management of these benign lessions of the paranasal sinuses.
doi:10.1007/BF02968752
PMCID: PMC3450937  PMID: 23119934
Schwannoma; paranasal sinus; sublabial; endoscope
21.  Large oculomotor schwannoma presenting as a parasellar mass: A case report and literature review 
Background:
Large schwannomas arising from the oculomotor nerve are very rare. The common site of tumor occurrence in this nerve is the segment within the interpeduncular cistern and the cavernous sinus.
Case description:
We report a case of a large left-sided oculomotor nerve schwannoma with minimal clinical signs and symptoms of oculomotor nerve involvement resembling a large parasellar mass. The radiological features of the mass were more consistent with a medial sphenoid wing meningioma causing brain stem compression. Complete resection of the tumor was achieved via a left pterional approach. The patient developed complete third nerve palsy postoperatively.
Conclusion:
The management of these large benign tumors with brain stem compression includes surgical resection. Intraoperative anatomical preservation of the third nerve was impossible given its course in the tumor. We discuss the pertinent literature and management of large oculomotor schwannomas.
doi:10.4103/2152-7806.63910
PMCID: PMC2908360  PMID: 20657696
Meningioma; oculomotor schwannoma; skull base
22.  Schwannoma causing resorption of zygomatic arch 
Schwannoma (also known as neurilemmoma, peripheral glioma and peripheral nerve sheath tumor) is a common, histologically distinctive, benign, usually encapsulated, peripheral nerve tumor of Schwann cell origin. Schwannomas can appear anywhere in the body, but are more frequently reported in the head and neck with an incidence of 25–48% in maxillofacial region. Resorption of bones due to schwannoma is rarely noticed in maxillofacial region. We hereby present a case report of schwannoma in a 35–year-old female, causing resorption of zygomatic arch along with review of literature.
doi:10.4103/0973-029X.80020
PMCID: PMC3125663  PMID: 21731284
Bone; erosion; mandible; neurilemmoma; schwannoma
23.  Epithelioid Malignant Peripheral Nerve Sheath Tumor Arising in a Schwannoma, in a Patient with “Neuroblastoma-like” Schwannomatosis and a Novel Germline SMARCB1 mutation 
Epithelioid malignant peripheral nerve sheath tumors arising in pre-existing schwannomas are extremely rare. We report an unusual example occurring in a patient with multiple schwannomas (schwannomatosis), all but one of which showed “neuroblastoma-like” histology. By immunohistochemistry, both the epithelioid malignant peripheral nerve sheath tumor and the schwannomas showed a complete loss of the Smarcb1 protein. Subsequent genetic evaluation revealed the presence of a novel germline mutation in the SMARCB1/INI1 gene in the patient and three of her children, two of whom were diagnosed with atypical teratoid/rhabdoid tumors of the brain.
doi:10.1097/PAS.0b013e3182380802
PMCID: PMC3241826  PMID: 22082606
Malignant peripheral nerve sheath tumor; schwannoma; schwannomatosis; SMARCB1/INI1
24.  Sinonasal schwannoma with secondary changes 
Schwannomas of the Sinonasal tract are very rare, representing less than 4% of schwannomas arising in the head and neck [1]. The most frequent site is the acoustic nerve; other locations include the scalp, oral cavity, pharynx, larynx, trachea, parotid gland, and middle ear. Secondary changes in a Schwannoma are a very rare entity. We report a case of Sinonasal schwannoma with pseudoangiomatous changes. The purpose of this article is to highlight the possibility of unusual presentation of a sinonasal schwannoma
doi:10.1007/s12070-008-0092-z
PMCID: PMC3450631  PMID: 23120562
Nasal; Schwannoma; Pseudoangiomatous
25.  Ancient schwannoma involving the median nerve: a case report and review of the literature 
Ancient schwannomas are benign long standing schwannomas of the neural sheaths. Histological findings are these seen as in conventional schwannomas, but ancient schwannomas additionally demonstrate cystic hemorrhagic changes and degenerative nuclei with pleomorphism and hyperchromasia. Due to the nuclear atypia, and cystic degeneration, ancient schwannomas might be confused with malignant tumors on histology and imaging, leading to a radical surgical approach. The median nerve is rarely affected. We present a rare case of an ancient schwannoma involving the median nerve at the mid humerus. The tumor slowly grew up within ten years and become symptomatic with local pain, mild numbness in the distribution of the median nerve in the palm and Tinel’s test. The tumor was successfully removed by separating it from the nerve fascicles to negative margins. Post-operatively local symptoms relieved but minor sensory loss in the median nerve distribution in the palm was noticed which improved in the following six months. Ancient schwannomas can be misdiagnosed as sarcomas due to specific imaging and histologic findings. Patients’ physical examination, history and fine radiologic and pathology features should be cautiously interpreted in order to achieve correct diagnosis and avoid unnecessary wide tumor excisions.
doi:10.1007/s11751-013-0158-7
PMCID: PMC3623924  PMID: 23546803
Benign neural sheath tumors; Ancient schwannoma; Neurilimoma; Median nerve

Results 1-25 (846331)