Two Cases of Lipofibromatous Hamartoma

Abstract

PURPOSE Lipofibromatous hamartoma (LFH) of nerve is a tumor-like lipomatous process principally involving the young persons. This is a rare disease characterized by a soft slowly growing mass surrounding and infiltrating major nerves and their branches of the palm and digits. LFH of nerve usually affects the median nerve, with the most common sites of presentation being the distal forearm and hand in the wrist or palm. It may cause symptoms of compression neuropathy and is associated with macrodactyly. Recently, MRI plays a major role in confirming the diagnosis of LFH. Therefore, we present two cases of LFH in the hand with MRI features and surgical management. METHODS: One is a 6-year-old girl with macrodactyly involving both soft tissue and bony parts of the second, third and forth digits of her right hand. The other is a 16-year-old boy involving the soft tissue of the second and third digits of his right hand, with pain and numbness, along with motor and sensory deficits in the median nerve distribution. To evaluate LFH, we enforced preoperative MRI and physical examination. After confirming the diagnosis of LFH, we proposed decompression of all compromised peripheral nerve to help alleviate pain and paresthesia to reduce the likelihood of permanent motor and sensory sequelae. RESULTS A characteristic feature on MRI is the appearance of serpentiform nerve fascicle surrounded by fibro-fatty tissue within the expended nerve sheet. Distribution of fat between fascicles is asymmetric. Two cases were treated by limited debulking of the redundant tumor tissue and excision of epineurial fatty tissue. These cases were performed with relief of symptom. CONCLUSION MRI confirms the diagnosis, and it also provides a detailed assessment of nerve involvement before the operation. Especially, on coronal images, the nerve has a spagetti-like appearance that is pathognomonic of LFH. Recommendations for early treatment include decompression of the carpal tunnel, debulking of the fibro-fatty sheath, microsurgical dissection of the neural elements and excision of the involved nerve with or without grafting.