Primary empty sella: a histologic and immunocytologic study.

A primary "empty" sella turcica was found incidentally at autopsy, and the anterior lobe of the pituitary gland was studied with the immunoperoxidase technique. All five adenohypophysial cell types, ie, somatotrophs, lactotrophs, corticotrophs, thyrotrophs, and gonadotrophs (containing follicle-stimulating hormone [FSH] and luteinizing hormone [LH], were present in adequate numbers and were well granulated, indicating normal hormone storage.

November 1998--70 year old woman with SLE, paraproteinemia and polyneuropathy.

A 70 year old woman developed a sensory-motor polyneuropathy 12 years after almost continuous treatment with hydrochloroquine for SLE. Sural nerve biopsy disclosed abundant lipid inclusions in schwann cells and vessels against a background of axonal degeneration. After cessation of therapy the patient improved moderately. This case underscores the usefulness of nerve biopsy in the study of management of patients with peripheral neuropathy associated with systemic illnesses.

June 1999--22 year old female with intraventricular mass.

A 22 year old female presented with a single seizure. CT scan and craniotomy demonstrated an intraventricular papillary tumor with histologic and immunohistochemical features indicative of a choroid plexus carcinoma. Even though the occurrence of this neoplasm is exceptional beyond childhood, pathologists should considered a malignant choroid plexus tumor when postulating the differential diagnosis of intraventricular papillary neoplasms in adults.

Case of the month: February 1999--54 year old man with severe muscle weakness.

A 54 year old man developed rhabdomyolysis one year after beginning treatment with a combination of lovastatin (an HMGCoA reductase inhibitor) and niacin. Muscle biopsy showed a severe necrotizing myopathy affecting both fibre types. Recovery occured gradually with cessation of medication. The spectrum of cholesterol lowering agent myopathy may include delayed cases of unusual severity.

April 1999--44 year old man with a bleeding intracerebral tumor.

A 44 year-old man presented with a three month history of increasing headache and evolving left sided hemiparesis that culminated in an haemorrhage into an intracerebral tumour which was partially resected. Histologic, immunohistochemical, electron microscopic and molecular studies are supportive of a diagnosis of primary embryonal rhabdomyosarcoma. While primary rhabdomyosarcoma of the central nervous system is rare, and 72% of previously reported cases are in the paediatric population, there appears to be subset of these tumours occurring supratentorially in the adult.

A case for hypothalamic acromegaly: a clinicopathological study of six patients with hypothalamic gangliocytomas producing growth hormone-releasing factor.

We report the histological, ultrastructural, and immunocytochemical features of six hypothalamic gangliocytomas associated with pituitary GH cell adenomas and/or acromegaly. In four patients, the gangliocytoma was intrasellar, and no hypothalamic investigation was performed; in two patients, autopsy confirmed hypothalamic involvement. Four patients had a gangliocytoma associated with pituitary GH cell adenoma and acromegaly; electron microscopy demonstrated an intimate association between neurons and adenomatous GH cells. One patient had a gangliocytoma and a GH cell adenoma but no clinical evidence of acromegaly. In the sixth patient, clinical and biochemical acromegaly was manifest, but no pituitary adenoma was demonstrated. Using immunocytochemistry, human pancreatic tumor GRF (hptGRF-40) was localized in the majority of neurons of all six gangliocytomas. The pituitary adenomas and nontumorous adenohypophyses were negative for hptGRF-40. In addition, somatostatin, glucagon, and GnRH were demonstrated within some neurons of several tumors; insulin and gastrin stains were equivocal. These findings confirm previous proposals of production of a GRF by such gangliocytomas. While the significance of other peptides found in some of the tumors is uncertain, the presence of hptGRF-40 in neurons of these gangliocytomas supports the theory that GRF excess is the mechanism responsible for over-production of GH and provides evidence for a syndrome of hypothalamic acromegaly.

Disulfiram neuropathy.

A 35-year-old man developed a distal sensorimotor polyneuropathy after taking disulfiram, 500 mg daily for five months. His symptoms improved after the drug therapy was discontinued. Clinical, electrophysiological, and pathological observations during the acute stage and during recovery suggest that disulfiram produces a distal axonopathy.

Primary intramedullary malignant lymphoma of the spinal cord.

The clinical and histologic features of a malignant intramedullary lymphoma of the spinal cord are reported. The duration of the disease was 9 months and the course was similar to other malignant intramedullary cord tumors. The tumor was confined to the cervical segment of the cord and histologically was composed of lymphocytes and plasmacytoid histiocytes. Effective treatment depends on tissue diagnosis.

Methanol optic neuropathy: a histopathological study.

The histopathologic effects of methanol on the optic nerve were studied in four patients. Circumscribed myelin damage occurred behind the lamina cribrosa in each nerve. Axons were preserved. Demyelination also occurred in cerebral hemispheric white matter in one patient. This selective myelinoclastic effect of methanol metabolism is probably caused by histotoxic anoxia in watershed areas of the cerebral and distal optic nerve circulations. Juxtabulbar demyelination may cause optic disk edema in methanol poisoning by compressive obstruction of orthograde axoplasmic flow. Visual loss may be due to disruption of saltatory conduction. Retrolaminar demyelinating optic neuropathy is an early morphologic correlate of visual loss in methanol intoxication.

Immunohistochemical detection of epithelial membrane antigen in normal perineurial cells and perineurioma.

The use of epithelial membrane antigen (EMA) as an immunohistochemical marker for normal and neoplastic perineurial cells is described. Normal perineurial cells react strongly for this antigen, which is also expressed by the cells of perineurioma. Instead, neurofibromas and schwannomas only show some peripheral or entrapped layers of EMA-positive cells. In traumatic and Morton's neuromas, bundles of neural fibers are wrapped in layers of EMA-positive perineurial cells. Neurothekeoma and granular cell tumor show no EMA reactivity. The detection of an epithelial marker in perineurial cells is in agreement with the concept of a "perineural epithelium" and seems to support a common embryologic origin for the perineurial cell and the equally EMA-positive arachnoidal cap cell. The availability of an immunohistochemical marker for the perineurial cell provides an easy and convenient tool for the evaluation of the participation of this cell in a variety of pathologic processes.

MR imaging of a hemorrhagic and granulomatous cyst of the ligamentum flavum with pathologic correlation.

Cysts of the ligamentum flavum are uncommon causes of neurologic signs and symptoms and usually are seen in persons over 50 years of age. We report a case of an epidural cyst located in the ligamentum flavum, which contributed to spinal stenosis in a 30-year-old man. Radiologic features were similar to those of a synovial cyst, but synovium was not identified histologically. The imaging and pathologic features were unusual, including hemorrhage and a fibrohistiocytic reaction with giant cells.

Metastatic alveolar soft part sarcoma presenting as a dural-based cerebral mass.

Sarcoma metastatic to the brain is uncommon and rarely occurs as the initial manifestation of tumor. Alveolar soft-part sarcoma, a rare but well studied subtype of a soft tissue sarcoma with a propensity for central nervous system invasion, presenting with brain metastases, has been reported only once previously. We report the case of a 28-year-old man who presented with partial seizures and who was found to have a homogeneously enhancing frontal lesion on a broad dural base disclosed by computed tomography. preoperatively, the lesion was thought to be a meningioma. The tumor was excised easily and had features typical of an alveolar soft-part sarcoma, which were revealed by light and electron microscopy as well as immunohistochemical analysis. Multiple lung nodules compatible with metastases were found on a chest film. Meningeal dissemination has been reported in a variety of sarcoma types, including rhabdomyosarcoma, fibrosarcoma, and leiomyosarcoma. We add alveolar soft-part sarcoma to this list and suggest that increased recognition of the propensity for these tumors to exhibit metastatic spread to the dura should eliminate diagnostic confusion and provide an earlier diagnosis of these rare lesions. The patterns of spread in metastatic sarcoma deserve further study.

Cerebral amyloid angiopathy and multiple intracerebral hematomas.

Two cases of simultaneous multiple intracerebral hematomas due to cerebral amyloid angiopathy (CAA) are described in patients who were both normotensive, elderly men. Because of their superficial location and the increasing feasibility of early and accurate diagnosis by computed tomographic scan, hemorrhage due to CAA should be considered in the differential diagnosis of single or multiple hemorrhagic lesions of the brain.

Granulocytic sarcoma of the spine in nonleukemic patients: report of three cases.

OBJECTIVE AND IMPORTANCE: Granulocytic sarcomas involving the spine in patients without myelogenous leukemia are rare. We report three cases and review the literature. CLINICAL PRESENTATION: Three patients presented with spinal epidural tumors, which caused spinal cord compression in one and cauda equina compression in two. INTERVENTION: All patients underwent surgery, and biopsies revealed histological features of granulocytic sarcomas. Bone marrow aspirates and biopsies showed no evidence of acute leukemia at initial presentation, for all three patients. CONCLUSION: Granulocytic sarcomas in nonleukemic patients are rare, and when they affect the spine they are frequently misdiagnosed. Appropriate therapy for these tumors requires early identification.

Perineurioma: a benign peripheral nerve tumor.

A unique benign peripheral nerve tumor, called a perineurioma, is described in this report. Light and electron microscopy and immunohistochemistry indicate that this tumor was derived from the perineurial cell. We discuss the ultrastructure, histogenesis, and management of this neoplasm.

The significance of spinal cord compression as the initial manifestation of lymphoma.

Eighteen patients with spinal cord compression caused by previously undiagnosed lymphoma were treated at our institution between 1976 and 1991. There were 14 male and 4 female patients (mean age, 58.2 years). The absence of bony involvement on radiographic images was a feature in 16 of the cases. All patients underwent laminectomy for decompression and tissue diagnosis, after which 5 underwent radiotherapy, 3 underwent chemotherapy, and 10 underwent combined-modality treatment. The functional outcome was improvement in 8 patients and no change in 10; no patient worsened after surgery. Eleven had advanced disease at diagnosis, while seven had limited disease, including three patients with localized extradural lymphoma. There were 16 cases of non-Hodgkin's lymphoma and 2 of Hodgkin's disease. Two patients had T-cell lymphoma and were among the longest survivors. DNA flow cytometry identified the low-grade tumors as diploid with very low proliferative indices, while the high-grade tumors all had high indices. At a mean observation time of 41.7 months, five patients have died of their disease, and seven remain in complete remission. Survival is markedly better than that reported for other malignant extradural tumors; however, even limited stage lymphoma can behave aggressively. Similarities in age, sex distribution, histological features, and the results of flow cytometry suggest behavior similar to extranodal lymphoma at other sites. Surgery to provide a tissue diagnosis, followed by combined radiotherapy and chemotherapy, is indicated for all cases.

Adult peripheral neuroepithelioma in Meckel's cave.

A case of peripheral neuroepithelioma arising from the trigeminal nerve in Meckel's cave is presented. The discussion emphasizes the pathological criteria for the diagnosis of a peripheral neuroepithelioma and the current controversy about the classification of this and related tumors.

Subarachnoid hemorrhage due to a spinal cord hemangioblastoma: case report.

A case of solitary spinal hemangioblastoma with spontaneous subarachnoid hemorrhage is presented. There was no features to distinguish the subarachnoid hemorrhage in this case from that due to an intracranial lesion. However, mild sensory symptoms involving the left arm and leg had preceded the hemorrhage by several months. The lesion was detected by cerebral angiography and computed tomographic scanning, and the diagnosis was confirmed at operation. A small syrinx was noted, and the lesion was totally removed without causing any deficit, despite its origin from the dorsum of the spinal cord. The tumor contained a false aneurysm, which had been visualized angiographically.

Intraneural ganglion: a case report with electron microscopic observations.

We report a case of common peroneal mononeuropathy caused by an intraneural ganglion in a 9-year-old boy. The mass and the contiguous nerve fascicles were excised under the operating microscope. Histologically, the cyst wall was composed of layers of elongated cells merging with fascicles that exhibited changes suggestive of a pressure-ischemia effect. Electron microscopy showed that the cells forming cyst wall were myofibroblasts, similar to the cells found in ganglia arising from joints elsewhere in the body. A review of the English literature on intraneural ganglia discloses 44 additional cases, of which 86% involved the common peroneal nerve. The most common clinical feature was motor dysfunction (followed by pain, sensory loss, and the presence of a palpable mass), and a significant male predominance is noted. The pathogenesis of this nerve lesion is discussed in light of our findings.