Endometrioid carcinoma of the fallopian tube: a clinicopathologic analysis of 26 cases.

Twenty-six endometrioid adenocarcinomas of the fallopian tube that occurred in patients 37 to 85 (average 57) years of age are described. Most of the patients presented with symptoms related to a pelvic mass but nine tumors were incidental findings at the time of operation. All the neoplasms were unilateral. Eighteen tumors were Stage I, four Stage II, two Stage III, and two Stage IV. Two tumors were primary in the fimbriated end of the tube. On gross examination the typical appearance was that of a fusiform swelling of the tube which contained a predominantly intraluminal neoplasm up to 6 cm in greatest dimension. Six separate tumors were present in one case. Microscopic examination revealed that 14 tumors were typical endometrioid carcinomas with foci of squamous differentiation in 7 cases, spindle cells interpreted as epithelial cells in 4 cases, and a trabecular pattern in 1 case. One of these 14 tumors was composed almost exclusively of oxyphilic cells lining glands. Twelve tumors were characterized by a mostly solid proliferation of small closely packed cells punctured by numerous glands that varied from small to cystic, imparting a superficial resemblance to an adnexal tumor of probable Wolffian origin. Benign stromal osseous metaplasia was noted in two Wolffian-like and one typical endometrioid carcinoma. Five tumors were grade 1, 11 were grade 2, and 10 were grade 3. Follow-up information was available for 18 patients. Five with noninvasive Stage Ia-0 tumors (intraluminal, noninvasive masses) were without disease at 2 to 5 (average 3) years postoperatively. Two of three patients with Stage Ia1 tumors were alive without recurrence at 2 and 3 years postoperatively. One of two patients with Stage Ia2 disease for whom follow-up is available was alive without disease 1.5 years postoperatively and one died of other causes 11.2 years postoperatively. One patient with Stage Ic disease had recurrence of tumor at 2 years; four with Stage II disease were without disease at 1.5, 2, 3, and 8 years; one with Stage IIIa disease died with disease at 4 years; and one with Stage IV disease died with disease after 5 years. Two additional patients had fimbrial tumors [Stage I(f)]; one of them died with disease at 7 years, and the other was alive without disease at 8 years. This small series indicates that endometrioid carcinomas of the fallopian tube are characteristically noninvasive or only superficially invasive and have a generally favorable prognosis. This subtype of tubal carcinoma should be distinguished from the more common neoplasms of serous type and from those of various other cell types.