Peliosis Hepatis Presenting As Pseudometastatic Liver Lesions During Adjuvant Therapy for Colon Cancer: A Case Report.

Peliosis hepatis (PH) is a rare benign vascular liver disorder that may closely mimic hepatic metastases on imaging, posing a significant diagnostic challenge in oncology. We report the case of a 54-year-old patient with left-sided nonmetastatic colon adenocarcinoma (pT4N0) treated surgically and receiving adjuvant Folinic acid, Fluorouracil, and Oxaliplatin chemotherapy for high-risk pathological features. During follow-up, contrast-enhanced computed tomography revealed a dysmorphic liver with a thin-walled lesion in segments II-III, highly suspicious for secondary hepatic involvement in the oncological context. A multidisciplinary decision led to a left hepatic lobectomy, and histopathological examination demonstrated PH, characterized by dilated congestive sinusoids and intraparenchymal hemorrhage, with preserved hepatic architecture and no evidence of malignancy or cirrhosis. Adjuvant chemotherapy was subsequently resumed and completed over a total of six months, with good tolerance. At the last follow-up, the patient showed no clinical, biological, or radiological evidence of disease recurrence. This case emphasizes the importance of including PH in the differential diagnosis of atypical hepatic lesions during oxaliplatin-based chemotherapy to avoid overstaging and unnecessary treatment modification.