Primary trabecular carcinoid of the ovary

A case of primary trabecular carcinoid of the ovary apparently occurring from the foregut element of a mature cystic teratoma was reported. The tumor was found incidentally and resected surgically from a 56-year-old female. The cystic teratoma found in the tumor was composed of only respiratory epithelium except a colliculus which showed a picture of tonsil-like tissue. No thyroid tissue was found. The trabeculae of the tumor cells were longer and wavier near the cystic teratoma, while they were straight and short at the periphery. The tumor cells had argyrophil granules but negative in argentaffin granules. The electronmicroscopy revealed many round neurosecretory granules measuring from 170 to 290 nm in diameter. The histogenesis was also discussed.