Case Report: Diffuse peribiliary metastasis from ovarian cancer mimicking sclerosing cholangitis without a detectable mass

Background Ovarian cancer typically spreads via peritoneal seeding, hematogenous, or lymphatic routes. Bile duct metastasis is extremely rare, and peribiliary metastasis manifesting as diffuse Glissonian sheath infiltration without a detectable mass lesion, to our knowledge, has not been well documented. Case presentation A 42-year-old woman with stage IVB high-grade serous ovarian carcinoma, previously treated with cytoreductive surgery and multiple lines of chemotherapy, presented with fatigue, anorexia, and mild jaundice. Magnetic resonance cholangiopancreatography (MRCP) revealed bile duct wall thickening, peribiliary edema (Glissonian sheath edema), and diffuse inflammatory changes without a discrete mass. Autoimmune and infectious workups were negative. Endoscopic retrograde cholangiopancreatography (ERCP) with biopsy showed micropapillary clusters of atypical cells. Immunohistochemistry was positive for CK7, CK19, PAX-8, P16, and mutant-type p53; CEA focally positive; ER negative; Ki-67 high. This confirmed metastatic high-grade serous carcinoma of ovarian origin involving the common bile duct wall. Imaging (MRI/MRCP) suggested diffuse peribiliary involvement compatible with Glissonian sheath infiltration, although the small biopsy did not directly sample the intrahepatic sheath itself. We hypothesize that the radiological changes reflect peribiliary lymphatic spread, but this remains an inference based on imaging-pathology correlation rather than a histologically proven mechanism. Effective biliary drainage could not be achieved because the patient was unable to tolerate the nasobiliary drain. She was discharged against medical advice and died shortly thereafter, according to family report. Conclusions In cancer patients with unexplained cholestasis, peribiliary metastasis should be considered even when no mass is seen on cross-sectional imaging. ERCP with biopsy and immunohistochemistry are essential for diagnosis.