Malignant Vestibular Schwannoma

A 61-year-old woman underwent a translabyrinthine resection of a right intracanulicular acoustic neuroma, which had been detected in the work-up of sudden hearing loss. At the time of surgery, the tumor was roughly twice as large as indicated by the magnetic resonance scan taken only 2 months previously. The tumor eroded the vertical and transverse crests and extended well into the cerebellopontine angle. It was impossible to distinguish the facial nerve proximal to the geniculate ganglion. All visible tumor was resected, along with the facial nerve. Histological evaluation showed a highly cellular tumor, with many mitoses and areas of necrosis, meeting the criteria for malignant schwannoma. The patient has no stigmata of neurofibromatosis, and has no known relatives with that condition. This case is only the fourth reported of a malignant vestibular schwannoma. The relationships between vestibular schwannoma, neurofibromatosis, and malignancy are discussed.     

Intrapelvic Malignant Schwannoma Resected Transsacrally

Malignant schwannoma arising in the retroperitoneum is rare. A 68-year-old man underwent transsacral resection for an intrapelvic tumor which proved to be a malignant schwannoma. The transsacral approach is simple and effective, and should be considered for primary management of retrovesicular and retroprostatic tumors.     

Malignant Schwannoma of a plantar digital nerve in the absence of neurofibromatosis

Malignant Schwannoma is a rare tumour of nerve sheath origin commonly associated with neurofibromatosis. A solitary tumour of plantar digital nerves in the absence of neurofibromatosis is even rarer and only one such case has been previously reported.¹We present the case of a patient who presented with symptoms and signs clinically diagnostic of a Morton’s interdigital neuroma localized in the web space between the hallux and the index toe. The patient had no external features of Von Recklinghausen’s neurofibromatosis (VRN) yet excisional biopsy revealed a malignant Schwannoma.     

定向快速寻找患儿隐匿头皮浅静脉方法探讨

将进行静脉补液治疗的患儿832例随机分为观察组与对照组,各416例。对照组采用常规方法穿刺;观察组 采用按、压、挤等定向快速寻找法,选择额上静脉或颞浅静脉穿刺。结果观察组一次穿刺成功率,高于对照组,而渗 漏、穿刺耗时则低于对照组(均P<0.01)。提示定向直接寻找隐匿头皮浅静脉穿刺法具有快速、高效的特点,能明 显提高穿刺成功率,减轻患儿痛苦,且家属满意。     

Malignant Schwannoma in an American Buffalo (Bison bison bison)

A case of a malignant schwannoma in a 20‐year‐old male American buffalo (Bison bison bison) from the Grand Park Zoo, Gyeonggi Province, Republic of Korea is reported. The animal showed no apparent clinical signs before death except for wound on the neck. Grossly, neoplastic nodules of various sizes were observed on the skin, lung, heart, liver, stomach, mesentery and kidney. Histologically, the neoplastic nodules were composed of fusiform cells that formed multidirectional bundles. The tumour cells were arranged in interlacing bands and bundles. The nuclei were atypical, hyperchromatic, with blunt or round ends. In addition, few mitotic figures were observed in the skin, lung, heart, liver, stomach, intestine and kidney. Several immunohistochemical stains, e.g. vimentin, cytokeratin (CK), smooth muscle actin (SMA), S‐100 and HMB45, were used in an attempt to differentially diagnose the tumour. The neoplastic cells tested positive to S‐100, but negative to vimentin, CK, SMA and HMB45. Based on the above findings, this case was diagnosed as a malignant schwannoma. To the best of our knowledge, this is the first report of a schwannoma in an American buffalo (B. b. bison).     

Primary Intracranial Malignant Schwannoma of Trigeminal Nerve. A Case Report with Review of the Literature

The authors report a rare case of primary intracranial malignant schwannoma of the trigeminal nerve occuring in a 30-year-old woman without von Recklinghausen's neurofibromatosis (VRNF). The tumour arose from the intracranial part of the left trigeminal nerve, without skull base destruction. The tumour was partially removed operatively, followed by focal 50 Gy irradiation, but unfortunately the tumour showed rapid regrowth. A second operation was attempted, but she died of cerebral infarction soon after operation. Histologically, the original tumour was characterized by the presence of foci of extremely high cellularity, pleomorphism and mitosis in an otherwise typical benign schwannoma. Immunohistochemically, the tumour cells were positive for S-100 protein even in the atypical areas, suggesting the tumour to be of Schwann cell origin. However, the recurrent tumour was composed of undifferentiated spindle cells, which were negative for S-100 protein. Thus, it is possible to consider that the S-100 protein expression could reflect the degree of differentiation of Schwann cells. Furthermore, the postoperative irradiation might have exacerbated the malignant progression in the present case.     

Malignant Cylindroma of the Scalp Arising in a Setting of Multiple Cylindromatosis: A Case Report

An unusual case of malignant cylindroma of the scalp arising in a 79-year-old white female with multiple cylindromatosis is presented. The tumor apparently arose from a cylindroma and had features of spiradenoma. Multiple cylindromatosis is an uncommon hereditary autosomal dominant disease, which is characterized by multiple skin adnexal tumors like cylindromas and trichoepitheliomas and occasional spiradenomas. Cylindroma is an uncommon benign tumor, which originates from skin appendages and is most commonly found on the scalp and face with a strong predilection for middle-aged and elderly females. Although cylindromas are usually benign neoplasms, carcinoma arising in such neoplasms is rare with only sporadic reports in literature. Her family history was negative for a similar disease. The patient’s main concern was painful lesions over her right ear that interfered with wearing of her glasses. The clinical, histological immunohistochemical features, and treatment are presented along with a review of the literature.     

Giant Ancient Schwannoma of the Posterior Mediastinum Cytologically Misdiagnosed as a Malignant Tumour. A Case Report

We report a case of a 45-year old woman who was found to have a giant mediastinal tumour with radiological degenerative changes. She underwent thoracotomy to remove the mass, which was eventually diagnosed histolo-gically as an ancient schwannoma, whereas cytological interpretation of the accompanying pleural fluid was malignant. Ancient schwannoma is a rare variant of schwannoma, histologically showing atypical features that may result in erroneous diagnosis of a malignant tumour. Clinical and radiological findings are important aids for further consideration of surgical removal of these potentially resectable tumours.     

Schwannoma of the gallbladder

Schwanomas of the biliary tract are very rare with about 55 reported cases. Schwanomas of the gallbladder are the rarest, probably with less then ten reported cases. We reported a 61 old woman in whom we did a cholecystectomy for a tumor of gallbladder 6.5 x 9 cm in diameter with a central softness which showed a histologic appearance of schwanoma. Ten years after surgery the patient is symptom-free and with no signs of recurrency.     

Schwannoma of the Penis

A case of a schwannoma of the penis is reported that was treated by surgical excision and diagnosed by S-100 immunoperoxidase staining.     

Schwannoma of the fibula

We describe a schwannoma located in the mid-diaphyseal region of the fibula of a 14-year-old boy. Radiologically this was an expansile, lytic, globular and trabeculated lesion. MRI showed a narrow transition zone with a break in the cortex and adjacent tissue oedema. Differential diagnosis included schwannoma, fibrous dysplasia, giant cell tumour and aneurysmal bone cyst. The tumour was excised en bloc, with marginal resection limits, and there has been no recurrence two years after surgery. Histopathological examination confirmed the diagnosis of classic schwannoma. There were typical hypercellular Antoni A zones, less cellular Antoni B zones, and diffuse immunoreactivity to S100 protein. This is the first report of schwannoma involving a long bone in a child.