Endometrial adenocarcinoma in spontaneous abortion

Localized Endometrial Proliferations of Pregnancy are Clonal Glandular Outgrowths Characterized by PTEN Loss and PIK3CA Pathogenic Variants

Gestational endometrium can demonstrate a spectrum of atypical but benign changes. One such lesion is localized endometrial proliferation of pregnancy (LEPP), first described in a series of 11 cases. To understand its biological and clinical importance, we explore the pathologic, immunophenotypic, and molecular features of this entity. Nine cases of LEPP identified in 15 years were retrieved from departmental archives and reviewed. Immunohistochemistry and next-generation sequencing using a comprehensive 446-gene panel were performed when the material was available. Eight cases were identified in curettage specimens performed after first-trimester pregnancy loss, and 1 in the basal plate of a mature placenta. The mean patient age was 35 (range 27-41) years. The mean lesion size was 6.3 (range 2-12) mm. Architectural patterns, often coexisting in the same case, included cribriform (n = 7), solid (n = 5), villoglandular (n = 2), papillary (n = 2), and micropapillary (n = 1). Cytologic atypia was mild in 7 cases and moderate in 2. Mitotic activity was low (up to 3 per 2.4 mm2). All lesions were associated with neutrophils. Background Arias-Stella phenomenon was present in 4 cases. Immunohistochemistry was performed in 7 LEPP, all of which demonstrated wildtype p53, retained MSH6 and PMS2, membranous beta-catenin, and positive estrogen receptor (mean 71%) and progesterone receptor (mean 74%). All were negative for p40 except 1 case (focal weak positivity). PTEN was markedly reduced in background secretory glands in all cases; in 5/7, LEPP foci showed a complete absence of PTEN expression. PIK3CA pathogenic variants were identified in 4/4 cases sequenced; 3/4 had inactivating PTEN mutations. Follow-up, available in 8 patients (mean length = 51 months, range 7-161), was conservative with observation only and showed no persistence or adverse outcomes. LEPP is characterized by intraglandular cribriform/solid architecture, positive estrogen receptor/progesterone receptor, PTEN loss, and PIK3CA and PTEN mutations. Although our findings indicate that LEPP is neoplastic, for now, we advise against diagnosing LEPP as endometrial carcinoma or hyperplasia because LEPP has a particular clinicopathologic context (concurrent gestation), distinct morphology (purely intraepithelial complex growth), and indolent outcome. Thus, it should be distinguished from endometrial intraepithelial neoplasia and carcinoma for which therapeutic interventions are indicated.

Endometrial carcinoma in a gravid uterus: a case report and literature review

Background

Endometrial carcinoma (EC) is rarely diagnosed during pregnancy. Therefore, the histopathological findings, clinical course, and gross appearance of the resected uterus during pregnancy are not well known. We present a case of EC diagnosed during pregnancy. In addition, we reviewed the literature dating from January 1995 to March 2019 for cases of EC diagnosed during pregnancy and within 15 months after pregnancy, and we discussed this topic to improve the understanding of this rare condition.

Case presentation

A 35-year-old woman underwent an urgent cesarean delivery in gestational week 35 due to antepartum bleeding caused by placenta previa. Hysterectomy was performed with the diagnosis of placenta accreta spectrum (PAS). Remarkably, the postoperative gross and histopathological examinations revealed an endometrioid adenocarcinoma (grade 1). The histopathological findings revealed a pattern similar to that of EC not related with pregnancy. Immunohistochemistry revealed an overexpression of the estrogen and progesterone receptors; however, the p53 expression was negative. We performed laparoscopic bilateral salpingo-oophorectomy and pelvic lymphadenectomy 102 days after the cesarean hysterectomy, and confirmed surgical stage IA without metastases. Our patient has had no recurrence in 4 years after the cesarean delivery.

An electronic search of the literature revealed 25 cases of EC (including our case) diagnosed during or after pregnancy. Sixteen of the 25 patients were diagnosed after abortions in the first trimester, 9 were diagnosed within 14 months of childbirth, and our case was the first with diagnosis from a surgical specimen of peripartum hysterectomy due to the PAS. In 23 of the 25 cases endometrioid adenocarcinoma grade 1 to 2 was found, and it seemed to have a good prognosis.

Conclusion

The present findings suggest that careful examination of a resected uterus is essential, even when surgery is performed for an obstetric indication. Our case is an extremely rare case of EC during pregnancy; the histopathological pattern was similar to that of typical EC, and no recurrence was noted. The high levels of estrogen and progesterone during pregnancy did not seem to promote tumor progression in our case.