Mandibular Metastasis as the First Manifestation of an Intrahepatic Cholangiocarcinoma.

PURPOSE: Cholangiocarcinoma is a malignant neoplasm with biliary differentiation and its metastatic spread to the oral and maxillofacial region is a rare event that can pose diagnostic challenges, especially when it is the initial presentation of the disease. METHODS: A 67-year-old woman presented with a painful and hard swelling in the right posterior aspect of the mandible with ulceration of the overlying mucosa. Radiological examination revealed a destructive lesion involving the body and angle of the mandible with cortical bone destruction. An incisional biopsy was performed. RESULTS: The histopathology showed an invasive and moderately differentiated adenocarcinoma with tubular and cribriform patterns of growth. Neoplastic cells were diffusely positive to cytokeratin (CK) 7, to 35βH11, and weakly to 34βE12 on immunohistochemistry, but were negative to estrogen, progesterone, and androgen receptors, HepPar-1, CDX-2, CK20, GATA 3, napsin-A, PAX-8, TTF-1, CD117, DOG1, p63, and S100 protein. A preliminary diagnosis of metastatic adenocarcinoma was rendered, and the patient was referred to an oncologic evaluation. An abdominal computed tomography performed revealed an intrahepatic mass, diagnosed as a cholangiocarcinoma on core needle biopsy. The patient was submitted to palliative care and died of disease complications three months after the diagnosis of the mandibular lesion. CONCLUSIONS: This case highlights the importance of an interdisciplinary approach, incorporating comprehensive clinical, pathological, and radiological correlations in reaching the appropriate diagnosis of a challenging metastatic lesion that developed in an unusual anatomical location.