SMALL-CELL NEUROENDOCRINE CARCINOMA OF THE ENDOMETRIUM

Ten cases of endometrial small cell neuroendocrine carcinoma are descr ibed. The ages of the patients ranged from 50 to 75 years (mean, 64 ye ars). Most of the tumors were bulky, intraluminal masses that invaded at least half of the myometrial wall. Small cells were the only malign ant element in two tumors. In the other eight, there were admixed elem ents of adenocarcinoma (five), adenosquamous carcinoma (two), or heter ologous mesodermal mixed tumor (one). Histologic examination of metast atic deposits in six cases revealed solely small cells in all but one. Immunohistochemical evidence of neuroendocrine differentiation was de monstrated in all tumors using the markers chromogranin, synaptophysin , leu-7, or neuron-specific enolase. Six of these tumors were original ly interpreted as mesodermal mixed tumors with a homologous, stromal-t ype sarcomatous component at initial pathologic examination, but were reclassified as carcinoma. Clinical follow-up of these 10 patients and an additional seven well-documented patients reported in the literatu re provided strong evidence for the aggressive nature of this neoplasm . Endometrial small cell neuroendocrine carcinoma is a rare, but aggre ssive neoplasm that can commonly be mistaken for a homologous-type mes odermal mixed tumor.