Low-grade Serous Carcinoma of the Ovary: Clinicopathologic Analysis of 52 Invasive Cases and Identification of a Possible Noninvasive Intermediate Lesion

Low-grade serous carcinoma (LGSC) is an uncommon but distinct histologic subtype of ovarian carcinoma. Although the histologic features and natural history of LGSC have been described in the literature, there is no robust correlative study that has specifically addressed histologic features in correlation with clinical follow-up. To refine the criteria for invasion patterns of LGSC and determine additional clinically pertinent morphologic features of LGSC predisposing to a more aggressive clinical course, the clinicopathologic features of 52 LGSCs were evaluated and compared with those of a large series of serous borderline tumors (SBT), with and without invasive implants. To qualify for LGSC, the tumor needed to demonstrate destructive invasion, nuclear atypia that was mild to moderate at most (grade 1 or 2), and a mitotic index that did not exceed 12 mitoses per 10 high-power fields. On the basis of histologic evaluation, destructive invasion was classified into 7 primary architectural patterns: (1) micropapillary and/or complex papillary; (2) compact cell nests; (3) inverted macropapillae; (4) cribriform; (5) glandular and/or cystic; (6) solid sheets with slit-like spaces; and (7) single cells. Five-year overall survival and disease-free survival for LGSC were 82% (median, 72 mo) and 47% (median, 54 mo), respectively. All the patients with fatal outcome demonstrated tumors showing invasion with predominant patterns of cribriform glands, micropapillae and/or complex papilla...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research