Rhabdomyomatous mesenchymal hamartoma in association with spinal dysraphism in an infant

Rhabdomyomatous mesenchymal hamartoma (RMH) is a rare benign entity with an increasingly heterogenous clinical presentation that is histologically characterized as a lesion with variably distributed elements within the dermis and subcutaneous tissues including mature adipose tissue, skeletal muscle, adnexal elements, and nerve bundles. It is associated with a range of syndromes and anomalies and has very rarely been identified in association with spinal dysraphism. Here we present one of only four cases reported in the literature of this entity occurring in association with a closed spinal dysraphism which is further differentiated by its presentation with an overlying dimple in the sacral skin as opposed to the previously reported cases of sacral skin tags and an atrophic plaque. On histological examination of the resected lesion, it was identified as an RMH.