U GIẢ NHẦY PHÚC MẠC KÈM U TUYẾN NANG NHẦY BUỒNG TRỨNG: THÁCH THỨC TRONG XÁC ĐỊNH NGUỒN GỐC TỔN THƯƠNG

Abstract

Background: Pseudomyxoma peritonei (PMP) is a clinical term referring to diffuse intraperitoneal accumulation of mucin secondary to mucinous neoplasms. It remains a controversial entity with respect to biological behavior and nomenclature. The majority of cases originate from appendiceal mucinous neoplasms. However, when PMP is associated with a morphologically benign ovarian mucinous tumor, determining the primary site becomes a significant diagnostic challenge.

Case presentation: A 32-year-old woman was incidentally found to have a left ovarian mass during a routine prenatal examination. Ultrasound and MRI revealed a large multilocular cystic lesion associated with free intraperitoneal fluid (ORADS 4–5). The patient underwent left oophorectomy, partial right oophorectomy, and appendectomy. Grossly, the tumor was a cystic mass filled with mucinous material. Histologically, it was consistent with mucinous cystadenoma lined by benign-appearing mucinous columnar epithelium. Peritoneal nodules, omentum, and small bowel specimens demonstrated abundant low-cellularity mucin without cytologic atypia. No neoplasm was identified in the appendix.

Conclusion: The final diagnosis was left ovarian mucinous cystadenoma associated with grade 1 pseudomyxoma peritonei. This case raises the question of whether the intraperitoneal mucin originated from a benign ovarian tumor or from an undetected primary lesion elsewhere. Comprehensive histopathological evaluation and a systematic diagnostic approach are essential for determining the origin of the disease.