DIFFUSE ECTOPIC DECIDUOSIS MIMICKING AS PERITONEAL CARCINOMATOSIS: A CASE REPORT OF A YOUNG FEMALE WITH MULTIPLE SEROSAL AND OMENTAL NODULES FOUND DURING A CAESARIAN SECTION

Abstract

Background & Objectives: Ectopic deciduosis refers to an abnormal occurrence of decidual tissue beyond the endometrium, predominantly on the surface of the uterus, fallopian tubes, ovaries and omentum. Diffuse omental and perito-neal involvement is a perplexing manifestation that may mimic peritoneal carcinomatosis. It is not accompanied by any symptoms and complications in most of the cases and does not require treatment. However, rarely it can present with acute abdomen or imitate peritoneal malignancy and, thus, associated with diagnostic difficulties and unnecessary interventions. Aim of this case report is to describe a rare case of peritoneal deciduosis in a young female, found incidentally, during a caesarean section, mimicking metastatic nodules. Afutile hysterec-tomy along with omentectomy was performed. Methods: A case of diffuse ectopic deciduosis mimicking as peritoneal carcinomatosis in a 29 years young female with full term pregnancy was found during a lower segment caesarian section, undertaken in a tertiary care teaching hospital of Lahore, Pakistan. The histopathological diagnosis was based on common technique of paraffin embedding and hematoxylin-eosin staining along with ancillary immune-histochemical evaluation. Results: Histopathological evaluation showed ectopic decidual tissue consisted of solid nests and loosely cohesive aggregates; large polygonal cells with abundant granular eosinophilic cytoplasm; sharply defined cell borders, bland nuclei with dispersed chromatin and single conspicuous nucleoli on the surface of uterus and in omental fat. Weak staining for CD30 was observed in the decidual cell cytoplasm and negative staining for CK and Calretinin in decidual cells was found. Calretinin and CK highlight benign mesothelial cells and help to rule out differentials of mesothelioma and metastatic carcinoma. Conclusion: Peritoneal deciduosis represents a rare entity and it is important to consider this condition in patients, especially in pregnant women, to prevent unnecessary intervention In addition, distinguishing this condition from malignant neoplasms will help in deciding correct treatment options.