Desmoid Tumor of the Porta Hepatis: A Rare Location With Unusual Clinical Presentation.

Background: Desmoid tumor is a locally aggressive fibroblastic/myofibroblastic neoplasm frequently arising in deep soft tissues. Although it can be well circumscribed, a desmoid tumor generally infiltrates surrounding tissues and tends to recur locally without metastasizing. While commonly arising in the extremities and abdominal wall, primary hepatic involvement is exceedingly uncommon. Case Report: We report the case of a 20-year-old woman presenting with progressive jaundice, pruritus, weight loss, and abdominal pain. Imaging revealed a 3 × 3 cm hepatic hilar mass with bile duct dilation, initially suggestive of cholangiocarcinoma. Histopathological examination following a tru-cut biopsy demonstrated features consistent with desmoid-type fibromatosis, confirmed by nuclear β-catenin positivity. Due to clinical deterioration, the patient underwent a left hemihepatectomy. The postoperative course was uneventful. Adjuvant tamoxifen therapy was administered, and follow-up imaging showed no recurrence. Despite the hormonal changes of a subsequent pregnancy, no disease progression was observed. Conclusion: This report highlights an extremely rare presentation of desmoid tumor in the hepatic hilum, mimicking malignancy. It underscores the importance of histopathological confirmation, multidisciplinary management, and individualized follow-up strategies, especially in women of reproductive age.