Pregnancy-related peritoneal ectopic decidua (deciduosis): morphological and clinical evaluation

Abstract

Objective: Ectopic decidual reaction (deciduosis) can be seen rarely on the peritoneum during laparotomy for a cesarean section for pregnancy, in addition to the ovary and cervix. The aim of this study was to evaluate the clinical, histopathological, immunohistochemical characteristics of ectopic decidua cases that were incidentally found in the peritoneum during a cesarean section. Material and Method:A total of seven cases where decidualization was found in the peritoneal biopsy taken during pregnancy at the Baskent University Adana Research and Medical Center, Department of Pathology were included in this study. The clinical features of the cases were obtained from their clinical folders. The morphological findings were recorded and the peritoneal biopsies were analyzed with keratin Pan Ab-1, calretinin, vimentin, HMB-45 and progesterone receptor antibody for immunohistochemical analysis. Results:The mean age for the seven cases was 36±4.16. The gestational age was 33 to 39 (mean 37.2) weeks. Microscopic evaluation revealed decidualized cells that were large polygonal and eosinophilic, some with vacuolated cytoplasm, that formed small nodules under the mesothelium of the peritoneum in all cases. Immunohistochemical staining showed positive staining of the cell cytoplasm with vimentin and positive staining of the cell nucleus with the progesterone receptor antibody in the decidual cells. Calretinin, keratin and HMB-45 stains were negative. Conclusion:Pregnancy-related peritoneal deciduosis develops with the effect of progesterone in pregnancy. It disappears without complication in the postpartum period. Immunohistochemistry may help the differential diagnosis of peritoneal deciduosis where problems are experienced differentiating the case from malignant mesothelioma or metastatic tumor.

Florid Diffuse Peritoneal Deciduosis Mimicking Peritoneal Carcinomatosis: A Case Report

“…Clinically absence of malignancy findings, microscopically lack of mitosis in decidual cells and, on immunohistochemical analysis, positive staining with vimentin and PR, negative staining with cytokeratin, calretinin, HBME-1 antibodies support ectopic decidua (1).…”

“…The lesions are found as small cell nests in the peritoneum in most of the cases, although they are found as widespread-florid deciduosis that entirely fills the fatty tissue in 3% of cases (1). Decidua shows features similar to decidualized endometrial stroma, being composed of a well-defined collection of bland-appearing large polygonal cells with distinct cell borders, round, centrally placed nuclei, small nucleoli and abundant eosinophilic cytoplasm (3).…”

“…Vacuolar degeneration can be seen in decidual cells and is related to the gestational age. A myxoid deposit can be seen in the stroma due to vacuole rupture if the decidual cell cytoplasm vacuolar degeneration is over 50% (1).…”

“…Ectopic decidua is observed usually in the uterus, cervix, fallopian tube, and ovaries. Peritoneal location is rare (1,2). Other rare sites include the appendix, omentum, diaphragm, liver, spleen, lymph nodes and renal pelvis, etc (2).…”

Decidualização Ectópica: Uma Entidade Esquecida

“…18 Contudo, apesar da deciduose poder estar relacionada com endometriose, certos casos não têm mostrado a consistência dessa associação, pois a lesão regride por completo 4 -6 semanas após a gravidez. [19][20][21][22] Por outro lado a progesterona parecer induzir a DE (ao invés dos progestativos utilizados para suprimir a endometriose), favorecendo a hipótese de se tratar de duas entidades distintas.…”