Cytologic features of endometrial papillary serous carcinoma.

Endometrial papillary serous carcinoma (EPSC) is an uncommon variant of endometrial carcinoma that histologically resembles ovarian serous carcinoma and has an aggressive clinical course. The cytomorphologic features of 17 patients with histologically confirmed EPSC of the endometrium were reviewed and compared with those of 20 patients with histologically typical endometrial adenocarcinoma (TEC). Preoperative cervicovaginal Papanicolaou smear results were available from 14 of the 17 patients with EPSC; 10 (71%) were positive, 1 (7%) was suspicious and 3 (21%) were negative for malignancy. Initial cervicovaginal smear results were available from all 20 patients with TEC; 7 (35%) were positive, 4 (20%) were atypical or suspicious and 9 (45%) were negative for malignancy. Twelve patients with EPSC had peritoneal washings or fluids examined; seven were positive and five negative. Twelve patients with TEC had peritoneal washings or fluids examined; two (17%) were positive and ten (83%) were negative. The cervicovaginal smears from patients with EPSC revealed numerous large tumor cells (with prominent nucleoli) frequently arranged in papillary clusters with background necrosis and, in two cases, amorphous material suggestive of psammoma bodies. In contrast, the smears of patients with TEC showed small to medium-sized cells with extensive phagocytosis and many background histiocytes. The diagnosis of EPSC should be considered when the cervicovaginal smear contains numerous papillary groups of large tumor cells with macronucleoli but without prominent phagocytosis, especially when structures suggestive of psammoma bodies are present. The peritoneal fluids in these patients are more often positive than in patients with TEC, a finding consistent with the propensity of EPSC to involve peritoneal surfaces.