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Synovial sarcoma most commonly occurs in the peri-articular regions of the extremities. The present report describes a rare case of primary biphasic synovial sarcoma of the pleura in an 18-year-old female. The diagnosis was made on the basis of light microscopy, immunohistochemistry, electron microscopy and the characteristic translocation found on cytogenetic analysis. Synovial sarcoma should be included in the differential diagnoses of pleural tumors. more...

A poorly differentiated primary retroperitoneal angiosarcoma with abundant intracytoplasmic and extracytoplasmic eosinophilic globules containing alpha 1-antitrypsin and alpha 1-antichymotrypsin is presented. Recognition of these globules may facilitate future diagnoses of the neoplasm in this or other locations. To the best of our knowledge, this is the first article on a primary angiosarcoma of the retroperitoneum. more...

A 40-year-old man had disseminated toxoplasmosis preceded by miliary tuberculosis and associated with skin anergy. In previously reported cases of disseminated toxoplasmosis, the three organs most commonly involved were brain, heart, and lungs. The histopathologic picture of toxoplasmal lymphadenopathy was not present in our case or in previously reported cases. Therefore, we believe that the diagnosis of disseminated toxoplasmosis should not be rejected simply because of the likely absence of toxoplasmal lymphadenopathy in biopsy material. The thymus in our case was morphologically abnormal and showed features suggestive of an autoimmune process. more...

Disseminated histiocytic proliferation and intestinal malakoplakia due to Mycobacterium intracellulare occurred in a 2-year-old white boy. Light and electron microscopic examination of autopsy material disclosed disseminated histiocytosis and malakoplakia of the intestine with numerous intracellular acid-fast bacilli. The isolated organism produced a similar disseminated histiocytosis and finally death when injected into experimental animals. A review of the literature showed only 12 previously reported cases of disseminated histiocytosis due to M intracellulare infection. We were unable to find a previous report of malakoplakia due to nontuberculous mycobacterial infection. more...

A tumor mass removed from the subcutaneous tissue of the shoulder of a dog had the light and electron microscopic features of extraneuraxial meningioma. The neoplasm probably arose from arachnoid cap cells displaced during embryogenesis. more...

Immunoglobulin deposits and DNA were identified by use of immunofluorescence microscopy within the ciliary process and choroid of a majority of (NZB X W)F1 mice with murine lupus. The number of animals with such deposits increased from 57% at 36 weeks of age to 90% at one year of age. Ultrastructural examination showed electron-dense deposits between the basement laminae of the endothelium and pigmented epithelium of the ciliary process, accompanied by alterations in the epithelial basement membranes. Similar electron-dense deposits were also identified in the vicinity of the lamina choroidocapillaris. The titer of antibody to DNA did not correlate with the presence of ocular deposits, suggesting that time is an important factor in the development of ocular immunopathology in these animals. more...

Argentaffin cells were searched for in the epithelial nests of 30 Brenner's tumors, with the Fontana-Masson stain for the screening. Although these cells were found in five tumors, ultrastructural examination of one case, in which the argentaffin cells were multiple, identified the cytoplasmic granules as lysosomes and not as amine precursor uptake and decarboxylation (APUD)-type granules. We conclude that the epithelial component of Brenner's tumors consists of urothelium only and does not include the cells containing argentaffin APUD-type granules. more...

Malignant lymphoma developed in the dorsum of the hand in a patient with a long-standing postmastectomy lymphedema. The tumor subsequently spread to involve skin of the forearm and arm. Growth and spread of malignant cells within the stagnant dilated lymphatics are the likely cause of the characteristic nodular dissemination of the tumor in a lymphedematous extremity, regardless of the type of neoplasm. more...