Spindle cell fragments in focal nodular hyperplasia of the liver: A case report

There are only few reports on the fine needle aspiration cytology (FNAC) findings of focal nodular hyperplasia (FNH) of the liver. A 30-year-old woman who had undergone surgery for a leiomyosarcoma of the calf, was found to have a hepatic mass five years later on imaging during routine follow-up. Fine needle aspiration was performed to rule out metastasis. Cytology revealed a few fragments of bland-looking spindle cells in a metachromatic stroma along with benign hepatocytes and bile duct cells. It was interpreted as "consistent with metastasis of leiomyosarcoma." The excised mass showed histologic features typical of FNH. Spindle cell fragments have not been previously observed in the FNAC of FNH. These fragments probably represent the muscular wall of the abnormal blood vessels of FNH. If smooth muscle fragment is seen accompanying benign hepatocytes and bile duct cells, one should consider the diagnosis of FNH in the needle aspirate.