In 1979, researchers described a series of young patients with clinically and histologically distinctive supratentorial gliomas which were designated pleomorphic (meningocerebral) xanthoastrocytomas (PXA). Significantly, patients with these neoplasms were reported to have a relatively favorable prognosis. The authors present a new case of PXA in a 32‐year‐old man. This case is unique for two reasons: (1) a relatively rapid fatal outcome with death 21 months after diagnosis; and (2) the presence, at autopsy, of extensive recurrent tumor with features of a malignant astrocytoma. Detailed electron microscopic and immunohistochemical studies, supporting the proposed subpial astrocytic origin of PXA, are presented. Literature pertaining to PXA is reviewed. This report illustrates the unique features of PXA and demonstrates its potential for aggressive behavior. Cancer 52:2055‐2063, 1983.

In the last 4 years, we have identified an acid-fast, autofluorescent organism in the stool of seven patients with diarrhea. The organism was identified as a cyanobacterium-like organism by the Centers for Disease Control (Atlanta) and as a coccidian by researchers in Peru and at the University of Arizona (Tucson). We present reports on the seven cases and a review of the literature. Three patients were known to be seropositive for the human immunodeficiency virus (HIV). All complained of watery diarrhea that had begun 3 days to 8 months before presentation. Colonoscopy in two patients showed a normal mucosal pattern; a biopsy for one of these patients showed chronic nonspecific inflammation of the colon. Examination of stool for ova and parasites revealed multiple oval and round nonrefractile organisms with well-defined walls that resembled large cryptosporidia; they measured 8-9 microns in diameter. These organisms did not stain by Giemsa or gram methods but were acid-fast by Kinyoun carbolfuchsin and Ziehl-Neelsen stains. The organisms fluoresced as blue under ultraviolet light. In the immunocompetent patients, diarrhea lasted an average of 19 days and resolved spontaneously. Diarrhea persisted in the HIV-seropositive patients. The clinical course and organism resembled those reported for travelers and HIV-seropositive patients. This organism may represent a newly identified cause of watery diarrhea in humans.

A patient with malignant Brenner tumor of the ovary is presented. The tumor responded to combined therapy with radiation plus doxorubicin + cyclophosphamide despite earlier failure on a single alkylating agent (levophenylalanine mustard). The patient next exhibited a brief response to chemotherapy with hexamethylmelamine + cyclophosphamide + amethopterin + 5‐fluorouracil. The histologic findings and ultrastructure of the tumor are discussed in detail. The morphologic features are consistent with the proposed origin of Brenner tumors from coelomic epithelium through a process of secondary urothelial metaplasia.