Pacinioma of Lumbosacral Skin in Closed Spinal Dysraphism.

Closed spinal dysraphism (CSD) is a congenital condition caused by a failure in secondary neurulation during embryogenesis. CSD is associated with characteristic cutaneous stigmata often identified clinically. Rarely, such stigmata have been reported to occur with complex congenital intraspinal lipomas containing Pacinian corpuscle hyperplasia. Herein, we present our case of an asymptomatic 8-month-old female who presented with a midline lumbosacral acrochordon-like lesion. MRI revealed a midline lipomatous lesion at S2-S3 with a fibrovascular stalk likely continuous with the acrochordon. Given the absence of neurological symptoms concerning tethered cord syndrome (TCS), only the skin lesion was removed for cosmesis. Subsequent histopathological examination revealed numerous Pacinian corpuscles in a background of dermal collagen and subcutaneous adipose tissue. No features suggested a co-existent peripheral nerve sheath lesion (such as a neurofibroma). Given the spinal cord abnormalities, and the histologic features of a pure proliferation of Pacinian corpuscles, a diagnosis of the so-called "Pacinioma" was made. To the best of our knowledge, only four other cases of complex intraspinal lipomatous lesions containing Pacinioma in the setting of CSD with a tethered cord have been previously reported. This case highlights the complexity of the cutaneous stigmata of CSD.