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.