High-grade primary peritoneal serous papillary carcinoma with a wide differential diagnosis: a diagnostic challenge.

Serous surface papillary carcinoma of the peritoneum is a rare malignant epithelial tumour that is histologically indistinguishable from high-grade serous papillary carcinoma of ovarian origin. We herein report a case of 66-year-old female with a history of breast carcinoma who presented with abdominal distension and shortness of breath. Imaging studies at the time of initial workup revealed multiple masses in abdominal cavity, and suspicion was high for metastatic carcinoma. The patient underwent exploratory laparotomy with total abdominal hysterectomy and bilateral salpingo-oophorectomy, partial colectomy, and omentectomy. Gross inspection of the omentum showed diffuse tumour caking, and frozen section evaluation of the omental nodules revealed adenocarcinoma with papillary features. Histological examination showed a high-grade papillary carcinoma with numerous psammoma bodies predominantly present within the omentum and peritoneum. Eventually, this case was determined to be a high-grade primary peritoneal serous papillary carcinoma involving the omentum, colon, and appendix, as well as the surfaces of the uterus, bilateral ovaries, and bilateral fallopian tubes. Knowledge of the primary organ of origin in cases of advanced papillary serous carcinomas is essential for both prognosis and staging, as well as for initiation of appropriate treatment. Close post-therapy follow up is required.