Fibrolipomatous hamartoma of the nerve: a clinicopathologic report of 13 cases.

[proteus syndrome]

Fibrolipomatous hamartoma of the nerve is a rare benign infiltrating condition of peripheral nerves with prominent cutaneous findings that has not being well described in the dermatologic and dermatopathologic literature .We sought to evaluate the clinical and histopathological features of this rare condition .We reviewed the clinicopathologic features of 13 cases to delineate their clinical presentation and histopathologic spectrum .All patients presented with unilateral lesions on the thenar areas , fingers , or both . In 7 cases the lesions presented congenitally and in 6 cases the lesions presented sporadically . Histologically , we found 2 Â patterns that have only been rarely mentioned before including cases with intraneural perineurioma -like features and cases with marked nerve hyperplasia .Only 13 cases were included in our study .This condition is an uncommon entity . The diagnosis of this disorder can be highly suspected on its macroscopic features . Predilection of the median nerve and the frequent association with macrodactyly are characteristic clinical findings .