Pathologic Findings in Prophylactic and Nonprophylactic Hysterectomy Specimens of Patients With Lynch Syndrome

abstract

 Women with Lynch syndrome (LS) have a high risk of developing endometrial carcinoma (EC) and, less frequently, ovarian carcinoma. As EC not uncommonly is the first malignancy, prophylactic hysterectomy (PH) has been increasingly implemented. In this study, we report the clinicopathologic features of a series of 70 LS patients who underwent either PH (n=39) or nonprophylactic hysterectomy (NPH) (n=31) at 3 tertiary referral centers. Among the 39 patients with PH, 2 had endometrial tumors seen grossly, whereas 37 showed no macroscopic lesions. Total inclusion of the endometrium was performed in 24/39 (61.5%). Abnormal histologic findings were identified in 9/39 (23.1%) PHs: 3 endometrial endometrioid carcinomas (EECs), including the 2 macroscopic and 1 microscopic (0.6 cm), and 4 atypical and 6 nonatypical hyperplasias.

NPH included those performed for endometrial and ovarian cancer treatment. Tumor sampling followed standard protocols. ECs comprised 26 EECs and 1 clear cell carcinoma, with a median size of 3.7 cm. Hyperplasia was observed in 10 (33.3%) as background in EC, in 4 showing atypia. Eight (29.6%) tumors were centered in the lower uterine segment (all EECs). EECs were predominantly well differentiated (53.8%) and FIGO stage I (77.8%). A papillary architecture was common (51.9%) and associated with microcystic elongated and fragmented foci in 4. Mucinous differentiation was observed in 25.9% of endometrial tumors, typically representing <10%. Most endometrial tumors (81.5%) showed tumor-infiltrating lymphocyte counts ≥42/10 high-power fields. Four tumors showed extensive necrosis. Eight patients had ovarian tumors (4 synchronous), including 2 endometrioid carcinomas, 2 clear cell carcinomas, 1 borderline clear cell adenofibroma, 1 Müllerian carcinoma of mixed cell types, 1 primitive neuroectodermal tumor, and 1 metastatic melanoma. Total inclusion of the endometrium should be done in all LS patients' surgical specimens without macroscopic lesions as some of these patients harbor preneoplastic or neoplastic conditions treatable at an early stage. The phenotype of LS-associated endometrial and ovarian tumors is variable and frequently includes features not commonly observed in sporadic cancers, but in our experience carcinomas were in general low grade and low stage.