Type I cutaneous meningioma of dorsal thoracic spine (Rudimentary Meningocele): A rare entity at an unusual site

Abstract

Cutaneous meningiomas (CM) are rare variants of meningiomas which are further classified into three subtypes. Type I CM (TICM) or Rudimentary meningocele (RM) is an uncommon developmental anomaly in which meningothelial elements are displaced into the skin and soft tissue. We present a case of 11 year boy with an upper back swelling since early childhood. His MRI spine showed a lesion at T4-T7 level with a fistulous tract connecting it to dural sac. Histopathology revealed clusters of oval to spindle cells arranged in whorls amidst collagen bundles and psammoma bodies. On immunohistochemistry these cells expressed EMA and Vimentin. A diagnosis of TICM was rendered based on these characteristic clinico-radiological & histopathological features. TICM pose a diagnostic challenge clinically and histopathologically and have an excellent prognosis. This is the 4 Indian case of RM and the 1 case of RM to be located in the spine in the Indian literature.