Progressive nerve territory overgrowth after subtotal resection of lipomatosis of the median nerve in the palm and wrist: A case, a review and a paradigm

Background: Lipomatosis of the nerve (LN) is a rare disorder characterized by the massive enlargement of peripheral nerves, frequently accompanied by generalized fibroadipose proliferation and skeletal overgrowth. The treatment of this disorder remains controversial, in part because of the rarity and the variability of presentation. Some authors have advocated total resection of this benign lesion including the functioning nerve, while others recommend symptomatic decompression alone. Methods: We have been routinely following a 10-year-old boy for lipomatosis of the median nerve at the wrist noted shortly after birth. He underwent median nerve resection accompanied by sural nerve grafting at another institute. We review the literature on LN and the efficacy of nerve grafting. Results: Clinically, he made a good recovery, with mild loss of thenar function and relatively preserved sensation. Serial magnetic resonance imaging over 5 years has revealed progression of the LN at both coaptation sites, fibrofatty proliferation within the nerve grafts as well as distal digital nerves, and enlargement of a fibrous scar at the coaptation sites. This has never been reported in the 9 decades of study of this disease. Conclusion: We present the first medium-term follow-up of a patient who underwent nerve sacrifice to attempt to cure the LN alongside a historical review of treatment. We believe that macroscopic gross total resection (i.e., microscopic subtotal resection) is insufficient in stopping the potential progression of this hamartomatous lesion because of the persistent effect of trophic factors.