Multifocal granular cell tumour of the biliary tree.

Fewer than 90 cases of granular cell tumour (GCT) of the biliary tract have been reported, including only five cases of multiple GCTs. We present the unusual case of a 40-year-old woman with multifocal GCTs affecting the intrahepatic biliary tree, which were initially suspected to be hepatic multiple metastases from a malignancy of unknown origin. The surgical specimen consisted of a hepatic segment in which five whitish nodular lesions were observed. On microscopic examination, nodular lesions were found in the portal tracts; these were composed of large polygonal cells with abundant highly granular cytoplasm. The nuclei were small and centrally located. The tumour cells tested diffusely positive for CD68-PGM1, S100 protein and α-inhibin, so a diagnosis of multifocal GCT of the biliary tree was made. Three years later, the patient is still alive and a MRI has shown no changes.