Primary carcinoid tumor of the kidney with special reference to its histogenesis

A case of primary carclnoid tumor of the kidney occurring In a 6&yeard women b reported. The tumor was 10 times 10 times 9 cm In she, did, yellowlsh-white In color, and associated with nuuslve hemorrhagk necrosis. Hlstoluglcally, it was composed of trebecular and anastornosing ribbonlike nests. The tumor cells showed argyrophllbity with the Grlmelius stain and cytoplasmlc PCwitMty for neumendocrlne markers, (Including chromogranln A, neuron-specifie endase, synap tophysln and Leu-7), prostetlc acid phosphatase, keratin and vimentln. Numerous cytoplasmlc neurosecretory granules were demonstrated uhstmcturally. These histologic and Immunohistochemical findings are consisten with the theory that this tumor has a common phenotype with that of carcinoid tumor aridng from the hlndgut or cloaca.