title: Malignant paraganglioma of retroperitoneum. Light, electron microscopic and ultrasonographic study.
abstract: A malignant retroperitoneal nonchromaffin paraganglioma in a thirty-four-year-old man was studied by light and electron microscopy. Histologically, the tumor cells displayed a tendency to surround granular, eosinophilic intercellular material and to form nests and pseudo-acini. Ultrastructurally, the tumor was composed of moderately well-differentiated epithelial cells intermixed with sparse sustentacular cells. An organoid pattern, reminiscent of the functional anatomic unit of nonchromaffin paraganglia, was seen occasionally. Epithelial cells formed pseudo-acini around dilated microvillous processes. These morphologic features are consistent with the neurocrestal origin of paragangliomas. The patient died ten months after presentation despite an initial favorable response to irradiation.
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D010235:Paraganglioma / Q000175:diagnosis / Q000473:pathology*; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D014463:Ultrasonography