Clinicopathological Features of Metastatic Colorectal Carcinoma in Multiple Primary Malignancies: A Case Report

Abstract

Background: The occurrence of multiple primary malignancies in a single patient is uncommon and presents significantdiagnostic challenges, particularly when metastatic lesions obscure the primary origin. Case: A 60-year-old postmenopausal woman with a history of untreated breast carcinoma presented with acute abdominal pain, progressive distension, and constipation. Imaging revealed multiple pelvic masses with omental involvement. She underwent exploratory laparotomy, including total abdominal hysterectomy, bilateral adnexal mass removal, and omentectomy. Intraoperatively, bilateral ovarian tumors, myometrial invasion, and omental nodules were identified. Histopathological examination showed well to moderately differentiated adenocarcinoma. Immunohistochemistry demonstrated that the ovarian, myometrial, and omental lesions were metastatic colorectal adenocarcinoma, positive for CK20, CDX2, and SATB2 expression. In contrast, a breast biopsy confirmed a metachronous luminal B–like invasive carcinoma, unrelated to the pelvic disease. Conclusion: This case highlights the diagnostic complexity of pelvic masses in patients with multiple malignancies. Ovarian metastasesfrom colorectal carcinoma can mimic primary ovarian tumors, especially in postmenopausal women. Bilateral ovarian masses with infiltrative adenocarcinoma should raise suspicion of metastasis, supported by a. CK20+/CK7-/SATB2+/CDX2+ profile. Comprehensive histopathological and immunohistochemical evaluation is essential for accurate diagnosis and appropriate management.