Histologic Patterns of Recurrent Endometrial Carcinoma.
Matthew Cesari, Douglas A Levine, Stephanie Wethington, Narciso Olvera, Daniel J Chiappetta, Karuna Garg, Robert A Soslow. Memorial Sloan-Kettering Cancer Center, New York, NY
Background: As targeted therapeutic agents are tested in recurrent endometrial carcinoma (REC), one cannot assume that patients with recurrence would benefit from targeted therapy based on evaluation of primary tumors. As part of a study evaluating the histologic, immunohistochemical (IHC) and genotypic (GEN) features of primary and REC, we first examine the histologic patterns of recurrence in this disease.
Design: Cases were identified (years 1999-2010) for which tissue blocks were available for both primary carcinomas and their recurrence(s). H&E-stained slides from the primary tumor and recurrence(s) were independently and randomly reviewed for histologic type and FIGO grade. The findings were considered discordant if any single pairing showed differences in either histologic type or FIGO grade.
Results: 31 primary tumors were identified with 39 recurrences. 24 (77%) cases included one recurrence and seven (23%) cases had multiple recurrences. Table 1 summarizes the histologic features of both primary and recurrent endometrial carcinomas. Concordant histology was seen in 20 (65%) cases; 11 (35%) cases were discordant. Two (66%) FIGO I endometrioid carcinomas were FIGO II at recurrence, while one appeared to recur as a tumor with ovarian-like low-grade serous morphology. Four (57%) FIGO II endometrioid carcinomas showed FIGO III (n=3) or ambiguous (n=1) histology at recurrence. One (25%) case, thought to represent FIGO III endometrioid carcinoma, recurred as serous carcinoma. Three (21%) serous carcinomas recurred as tumors with endometrioid patterns (n=2) or undifferentiated (n=1) carcinoma. All three primary carcinomas with ambiguous histology remained so at recurrence.