Primary peripheral primitive neuroectodermal tumors of the spinal cord: report of two cases and review of the literature.

Primary intraspinal peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare tumors with only seven reported cases in the literature. The histopathologic diagnosis of this tumor is complex and has led to a variety of treatment approaches. The distinction between central and peripheral type primary spinal cord PNETs has not always been made in the literature, leading to a paucity of data in this disease. We present here two young patients with primary intraspinal pPNET, their treatment and outcome. The first patient, a 27 year old male, presented with an intradural mass extending from L2 through L5, after multiple relapses, he is currently alive with disease after 72 months, the longest survival yet reported. The second patient, a 16 year old female, presented with an intradural mass at the cauda equina from L2 through L5, and is currently alive with responsive disease at 5 months after initial diagnosis. Here, we discuss the clinical course, the pathology and treatment for this disease and review the literature.