Giant plexiform schwannoma: a report of two cases with soft tissue and visceral involvement

We report two cases of massive, solitary, plexiform schwannoma. One was a 9-cm subcutaneous lesion on the hip of a 72-year-old man who had become aware of the slow-growing tumor 50 years earlier; the other is the first reported plexiform schwannoma to arise in a visceral organ: it arose in the ascending colon of a 54-year-old man and exhibited a dumbbell configuration with submucosal and subserosal components. Neither patient had neurofibromatosis or schwannomatosis. Both tumors were well-circumscribed and multinodular, and both showed a plexiform architecture. Microscopically, the nodules were composed primarily of Antoni A tissue, replete with nuclear palisading and Verocay bodies. Examination by immunohistochemistry and electron microscopy demonstrated the features of well-differentiated Schwann cells; nodules were surrounded by attenuated, residual perineurium. Both patients followed a benign clinical course, without recurrence or metastasis. Neither the large tumor size nor the unusual locations affected the biologic behavior of these neoplasms. A massive plexiform schwannoma must be distinguished from a malignant peripheral nerve sheath tumor and from a plexiform neurofibroma, a tumor prone to malignant transformation.     

Enteropathogenic E. coli: intimacy redefined

A 42 yr old male presented with left facial weakness. MRI showed lesions affecting the distal seventh nerve and third division of the trigeminal nerve. The seventh nerve was biopsied and showed a malignant epithelioid schwannoma. The patient underwent extensive resection followed by irradiation. This is one of very few examples of intracranial malignant peripheral nerve sheath tumors and the first reported example of an intracranial malignant epithelioid schwannoma. The literature is reviewed and completeness of resection appears to be the most pertinent prognostic factor.     

Atypical sporadic lymphosarcoma in a 7-month-old Holstein heifer

A 7-month-old calf with a firm, diffuse infiltration of the left hind limb with sciatic nerve motor deficit was presented. The cytology indicated a malignant, round cell tumor and at necropsy, tissues were positive to a Kappa-lambda immunohistochemistry test. The final diagnosis was sporadic bovine leukosis, juvenile form.     

Peripheral nerve hemangioblastoma

Capillary hemangioblastoma (HB) is a benign, highly vascular tumor limited almost exclusively to the central nervous system (CNS). It occurs primarily in the posterior fossa and less often in the spinal cord. We report three cases of HB occurring in peripheral nerve, two intradural tumors arising in a C4 and a cauda equina nerve root, respectively, and a third lesion in the sciatic nerve at mid thigh. The patients, 1 woman and 2 men, ranged in age from 25 to 49 years. Two had von Hippel-Lindau disease, an association usually found in one-third of CNS HBs, and one had a family history of pheochromocytoma. In every way, HBs of peripheral nerve were indistinguishable from their CNS counterpart. Ranging in size from 1.5 to 5.5 cm in diameter, the tumors were well circumscribed and contained a myriad of small caliber vessels lined by endothelial cells and surrounded by pericytes. Throughout, the lesions were rich in large, often vacuolated stromal cells. In all of the cases, these stained strongly for vimentin and neuron-specific enolase; only one showed focal S100 protein reactivity. Surgical therapy required excision of the affected nerve roots in the first two cases. In the third case, prominent extension of the tumor within epineurium permitted a microsurgical resection with sparing of sciatic nerve fascicles. No tumor recurred during a follow-up period of 5 to 20 months.     

Ancient schwannoma of the submandibular gland: a case report

Schwannomas (neurilemmomas) are neurogenic tumors that arise from the Schwann cells of the neural sheath. They are most often benign and solitary. Extracranial schwannomas are rare, and can be mistaken for metastatic disease or other non-neurogenic tumors. Ancient schwannoma is a rare variant of schwannoma with a course typical of a slow-growing benign tumor. Histologically, it can be confused with a malignant mesenchymal tumor. An unusual case of an ancient schwannoma of the submandibular gland is reported. The clinical, histological and surgical aspects of this tumor are discussed, and the literature regarding this rare entity is reviewed.     

Drug resistant typhoid fever

BACKGROUND: Malignant schwannomas are rare malignant mesenchymal tumors often associated with neurofibromatosis. They occur less frequently in the head and neck than in other regions. PATIENT: A case history of a primary malignant schwannoma of the head and neck area in a 27-year-old man is reported. The tumor was located in the left submandibular region. The patient did not have any functional deficits. The tumor was totally removed. There have been no signs of either recurrence or metastasis within the two years following diagnosis and surgery. DISCUSSION: The microscopic and immunohistochemical findings are presented, and the importance and therapy of this very rare malignant tumor of the head and neck area are discussed. CONCLUSION: Malignant schwannoma in the head and neck region is rare. Radical resection is the treatment of choice.     

Benign retroperitoneal schwannoma mimicking a pancreatic cystic tumor: case report and literature review

A rare case of benign retroperitoneal schwannoma mimicking a pancreatic cystic tumor is reported herein. The tumor mass, based on a computed tomography scan and an abdominal echo examination, was initially suspected to be a mucinous cystadenoma or cystadenocarcinoma of the pancreas. However, the surgical and pathohistological findings made a final diagnosis of benign pancreatic schwannoma. The patient is doing well at a 2-year follow-up. The tumor, 18x17x15 cm in size, represented the largest among reported pancreatic schwannomas. Furthermore, a comprehensive review of reported cases of pancreatic schwannoma was carried out to summarize corresponding findings, including benign or malignant forms, adherence to other tissues, cystic change of the tumor, as well as relation to von Recklinghausen's neurofibromatosis.     

Thoracoscopic resection of schwannoma: a report of two cases

We have performed thoracoscopic resection of schwannoma without intraspinal extension in two asymptomatic cases confirmed by chest roentgenogram and computed tomography: the case 1 with the tumor as large as 4.0 x 4.0 x 3.5 cm found in the paravertebral fifth Intercostal space, the case 2 with the tumor as large as 3.2 x 2.5 x 1.8 cm found on the first rib in contact with the supreme intercostal vein. In the operation of case 1, the dilated fifth intercostal vein in contact with the tumor which could not be controlled by Endo-Clip was doubly ligated by the use of Knot-Pusher. The tumor was successfully dissected from the chest wall and proved to arise from the fifth intercostal nerve. The tumor was brought into Endo-Pouch and extracted through one of the skin incisions which was minimally enlarged to accommodate the pouched lesion. In the operation of case 2, curved forceps facilitated the procedure because the tumor located near the apex of thorax. The tumor was found to originate from sympathetic nerve and removed through the minimally enlarged incision as case 1. We conclude as the following. The benign tumor found in the mediastinum or the chest wall is amenable to thoracoscopic treatment. In thoracoscopic procedure, as the operation under thoracotomy, we must acquire skills of standard operative technique, i.e., suture or ligation, because those skills are necessary when Endo-Clip or Endo-GIA cannot be used. The skin incision should be minimally enlarged finally when the specimen is extracted to minimize operative intervention.     

CD44 expression is aberrant in benign Schwann cell tumors possessing mutations in the neurofibromatosis type 2, but not type 1, gene

Atypical expression of CD44 splice variants has been implicated in the progression of numerous tumors. This abnormal CD44 expression is presumed to result from gene alterations that cause tumorigenic transformation. Two tumor types that have been linked to specific gene alterations are schwannomas, which have mutations in the neurofibromatosis (NF) type 2 (NF2) gene, and neurofibromas, which characteristically possess NF type 1 (NF1) gene mutations. We examined CD44 expression in normal sciatic nerves, in schwannomas with confirmed NF2 mutations, and in neurofibromas and malignant peripheral nerve sheath tumor tissue and cell lines from NF1 patients. Compared to normal nerves, schwannomas express higher total levels of CD44 and additional splice variants, whereas CD44 expression in neurofibromas is unaltered. Malignant peripheral nerve sheath tumor tissue and cell lines express the CD44v6 epitope, which is not expressed by normal Schwann cells or by other Schwann cell tumors. These data indicate that altered CD44 expression correlates strictly with mutations in the NF2 but not NF1 gene and suggest that CD44v6 might be a marker for the malignant transformation of Schwann cells.     

Gastric schwannoma

A rare case of gastric schwannoma is reported. A 36-year-old woman whose endoscopy showed a mucosa tumor, biopsy findings were suggestive for leiomyoma. Diagnosis was made only with postoperative histology that revealed the benign schwannoma. Immunohistochemical staining showed positivity for S-100 protein and the neuron specific enolase, schwannoma is often associated with Von Recklinghausen's disease. Surgical resection is recommended as their malignant potentiality. Gastric and small intestine localizations are often with bleeding. They also represent almost the 24% of all gastrointestinal stromal tumors (GIST) and the 4% of all primary retroperitoneal tumors.     

Benign schwannoma of the breast: report of a case

We report herein the case of a 62-year-old woman who presented to our hospital for investigation of occasional pain in her left breast. Although there was no mass palpable in her left breast, mammography and ultrasonography revealed a round tumor in the upper outer quadrant of the right breast. Although the mammography findings indicated that the tumor was benign, the possibility of a malignant neoplasm could not be ruled out by the ultrasonographic images. A final diagnosis of schwannoma was established by histopathological examination of the excised mass.     

Identification and characterization of two thrombin-activatable fibrinolysis inhibitor isoforms

OBJECT: The indications, operative findings, and outcomes of vestibular schwannoma microsurgery are controversial when it is performed after stereotactic radiosurgery. To address these issues, the authors reviewed the experience at two academic medical centers. METHODS: During a 10-year interval, 452 patients with unilateral vestibular schwannomas underwent gamma knife radiosurgery. Thirteen patients (2.9%) underwent delayed microsurgery at a median of 27 months (range 7-72 months) after they had undergone radiosurgery. Six of the 13 patients had undergone one or more microsurgical procedures before they underwent radiosurgery. The indications for surgery were tumor enlargement with stable symptoms in five patients, tumor enlargement with new or increased symptoms in five patients, and increased symptoms without evidence of tumor growth in three patients. Gross-total resection was achieved in seven patients and near-gross-total resection in four patients. The surgery was described as more difficult than that typically performed for schwannoma in eight patients, no different in four patients, and easier in one patient. At the last follow-up evaluation, three patients had normal or near-normal facial function, three patients had moderate facial dysfunction, and seven had facial palsies. Three patients were incapable of caring for themselves, and one patient died of progression of a malignant triton tumor. CONCLUSIONS: Failed radiosurgery in cases of vestibular schwannoma was rare. No clear relationship was demonstrated between the use of radiosurgery and the subsequent ease or difficulty of delayed microsurgery. Because some patients have temporary enlargement of their tumor after radiosurgery, the need for surgical resection after radiosurgery should be reviewed with the neurosurgeon who performed the radiosurgery and should be delayed until sustained tumor growth is confirmed. A subtotal tumor resection should be considered for patients who require surgical resection of their tumor after vestibular schwannoma radiosurgery.     

Transverse and T fractures with fracture of the posterior wall of the acetabulum. Results of orthopedic and surgical treatment. Apropos of 52 cases

A patient developed delayed facial nerve palsy at the level of House-Brackmann grade I to grade III 10 days after vestibular schwannoma surgery by the suboccipital transmeatal approach. The palsy had completely recovered after one month. Immunological study showed reactivation of herpes simplex and magnetic resonance (MR) imaging demonstrated an abnormal enhancement pattern of the facial nerve; intense enhancement of the distal intracanalicular segment and labyrinthine segment, similar to the MR findings for Bell's palsy. A prospective control study on the enhancement pattern of the functionally preserved facial nerve after vestibular schwannoma surgery in six cases showed a similar pattern to that of the normal facial nerve. Based on these findings, we propose the hypothesis that herpes simplex reactivation is an underlying cause of delayed facial palsy after vestibular schwannoma surgery.     

Aetiology, cost of antimicrobial therapy and outcome in neutropenic patients who developed bacteraemia during antimicrobial prophylaxis: a case-control study

The authors describe one case of purely epithelioid schwannoma of the ulnar nerve and discuss the therapeutic management. A 44 year-old man was referred to us for a fusiform, movable mass in the left ulnar nerve and was removed by a wide en bloc excision. Intraoperative nerve action potentials were performed both prior to and following excision of the lesion. Histologically, the tumor was composed of round or polygonal cells arranged in necrotic clusters and anastomosing cords. There were areas of spindle cells. The epithelioid cells were round with abundant cytoplasm. Mitoses were frequent. S100 protein immunoreactivity was present diffusely in tumor cells (both nuclear and cytoplasmic), whereas cytokeratin, NSE, and anti-melanoma reactions gave negative results. After a 13 months, the patient's neurological conditions are excellent and there are no signs of either recurrence or metastasis.     

Procurement, preservation, and transport of cadaver kidneys

Numerous findings support the possibility that highly sulfated proteoglycans are inhibitory molecules which, at high concentration relative to growth-promoting signals, may regulate or guide axonal growth. Although most studies implicate sulfated proteoglycans in the poor regenerative capacity of the central nervous system, inhibitory proteoglycans also may play an important role in the successful regeneration of axons within peripheral nerve. Cultured rat schwannoma and Schwann cells produce chondroitin sulfate proteoglycan (CSPG) which binds to and inhibits the neurite-promoting activity of laminin [Muir et al. (1989) J. Cell Biol. 109:2353]. In the present study, we found a similar neurite-inhibiting activity associated with CSPG isolated from normal adult rat sciatic nerve. Following nerve crush injury, this inhibitory activity was increased sevenfold in regenerating nerve distal to the injury. This increase was largely attenuated by in vivo administration of the proteoglycan synthesis inhibitor beta-D-xyloside. In normal adult nerve, immunolabeling for CSPG core protein was concentrated in slender bands surrounding axon-Schwann cell units and within nodes of Ranvier. Following nerve crush injury, immunolabeling of CSPG and laminin became more intense in distal nerve and CSPG increased within endoneurium and surrounding nerve sheaths. Embryonic dorsal root ganglionic neurons cultured on longitudinal nerve sections extended neurites along the exposed surfaces of Schwann cell basal lamina. The length of neurites was increased 58% on normal nerve sections pretreated with chondroitinase. Even though laminin levels were elevated in basal lamina of injured nerve, neuritic growth on sections of injured nerve was not significant increased unless sections were pretreated with chondroitinase. These results indicate that inhibitory CSPG is up-regulated in injured nerve and plays a role in regulating axonal regeneration.     

Malignant triton tumour of the spine: a case report

A malignant triton tumour is a malignant schwannoma with rhabdomyoblastic differentiation, and is a very rare occurrence. We describe the case of a 33-year-old man with neurofibromatosis type 1 who presented with paraplegia. Pathological examination of an intradural, extramedullary tumour excised at lumbar laminectomy demonstrated a malignant schwannoma with rhabdomyoblastic differentiation. We believe this is the first documented case of a malignant triton tumour of the spine.     

Strategies for improving blood pressure control

OBJECTIVE: To investigate the sensitivity of echography vs magnetic resonance imaging (MRI) or computed tomography (CT) for detecting extraocular extension of choroidal malignant melanoma. DESIGN AND SETTING: Retrospective review at a university referral center. PARTICIPANTS: All patients with histopathologically proven extraocular extension of choroidal malignant melanoma evaluated at the Bascom Palmer Eye Institute, Miami, Fla, between January 1, 1988, and August 31, 1997. INTERVENTIONS: The histopathology records of all patients who underwent enucleation for choroidal malignant melanoma or biopsy of an extraocular nodule during the study period were reviewed. The records and imaging studies of patients who were found to have extraocular extension of choroidal malignant melanoma were then reviewed to determine the sensitivity of preoperative echography vs MRI or CT for detecting extraocular tumor extension. RESULTS: A review of 297 histopathology records identified 13 patients with extraocular extension of choroidal malignant melanoma. Three patients with only microscopic extraocular tumor extension were excluded from the study. Of the remaining 10 patients, all underwent ocular echography preoperatively, 5 underwent orbital MRI, and 2 underwent orbital CT scanning to evaluate for extraocular extension of tumor. Extraocular tumor extension was demonstrated in 10 patients (100%) with echography and in 2 (29%) of 7 patients with MRI (2 of 5 patients) or CT (0 of 2 patients). In no instance did MRI or CT demonstrate extraocular tumor extension that was not identified with echography. CONCLUSION: At this institute, ocular echography is more sensitive than MRI or CT for the detection of extraocular extension of choroidal malignant melanoma.     

Continent urinary diversion using a tubulized sigmoid segment. An alternative to trans-appendicular diversion]

Schwannomas are very rare in the nose and paranasal sinuses; their presence both intra-and extracranially is still rarer. Here we present a case of nasoethmoid schwannoma with intracranial extension into anterior cranial fossa. Clinical, radiological, pathological and operative findings are discussed and the literature is reviewed. We recommend bifrontal craniotomy for removal of intracranial and nasoethmoid extensions of this tumor.     

Schwannoma of the obturatorius nerve as differential diagnosis in cystic adnexa tumors

We report on a case of benign retroperitoneal schwannoma involving the obturator nerve. Discussing the difficulties of diagnosis and treatment the following became clear: 1.) Clinical examination, ultrasound and computed tomography are not helpful to differentiate a retroperitoneal schwannoma from a cystic ovarian tumour; this problem can perhaps be overcome by MR imaging. 2.) The diagnosis should be borne in mind in cases of retroperitoneal tumours of unclear origin. Appropriate surgery is necessary to avoid nerve damage and paralysis.