Abstract

This study aimed to clarify neuroendocrine features (NEF) in poorly differentiated (G3) endometrioid adenocarcinoma of the endometrium and to evaluate its prognostic significance. Forty cases with G3 carcinoma were investigated for NEF immunohistochemically. The histopathologic specimens were immunostained with chromogranin A, synaptophysin, and leu-7, using the labeled streptavidin–biotin method. The staining pattern was classified into diffuse, partial, or focal. The NEF was compared with clinicopathologic variables, including patients' survival. Chromogranin A was positive diffusely in 1 patient (2.5%), partially in 8 (20%), and focally in 13 (32.5%). Synaptophysin was positive diffusely in one (2.5%), partially in three (7.5%), and focally in nine (22.5%). Leu-7 was focally positive in 10 (25%) patients. The overall positive rate of the three neuroendocrine markers was 62.5%. A patient with diffusely positive staining for both chromogranin A and synaptophysin was diagnosed with neuroendocrine carcinoma. One or more neuroendocrine markers were positive in 25 cases (62.5%). Positive NEF was correlated with clinicopathologic parameters such as stage and myometrial invasion. The survival of the patients with positive NEF, especially with positive leu-7, was significantly lower than that without NEF. NEF was detected immunohistochemically in approximately 63% of the G3 carcinomas, and these patients had a poor prognosis.