Villous adenoma of the duodenum. A clinicopathologic study of five cases.

Villous adenoma of the duodenum (VAD) is a rare tumor occurring predominantly in middle-aged adults and most commonly found in the second portion of the duodenum. The authors describe five cases of VAD and discuss histologic criteria for diagnosis of malignant transformation. Diagnostically, more than 90 per cent of all lesions are identified by upper gastrointestinal series and endoscopy. Treatment of choice for benign lesions is local excision, while malignant lesions should be treated with more extensive resection. In situ carcinoma in the elderly should be managed on an individual basis.

Maxillofacial synovial sarcoma. Light- and electron-microscopic study of two cases.

The light microscopy and ultrastructural features of two maxillofacial synovial sarcomas are presented. By light microscopy, one of the tumors revealed the typical biphasic pattern while the other was predominantly fibrosarcomatous. Ultrastructurally, both cases revealed a biphasic pattern. Epithelial-like cells displayed abundant mitochondria, Golgi profiles, electron-dense bodies, cytolysosomes, and thin filaments. Stromal cells were spindle-shaped and provided with smaller cytoplasm and scant organelles, mainly consisting of profiles of rough endoplasmic retuculum, mitochondria, and free ribosomes. Pseudoglandular spaces lined by cuboidal to flattened epithelial-like cells with apical microvilli were numerous. Basal lamina and intercellular junctions were prominent in one case, but sparse in the other. The most undifferentiated tumor revealed many intercellular clefts containing filopodia among the epithelial-like cells; occasional intracyltoplasmic lumina were also present. These findings are somewhat similar to those reported in normal and nonneoplastic diseases of the synovium. However, the location of the tumors in areas normally devoid of synovium suggests one more that they might arise from nonspecialized primitive mesenchyme.