Schwannomatosis in a patient with a pelvic mass

Schwannomatosis is the most recently recognized form of neurofibromatosis in which patients harbor multiple non-vestibular nerve schwannomas. The diagnosis is contingent on excluding neurofibromatosis Type 2 (NF2), to which it is related. The authors present a case of schwannomatosis diagnosed fortuitously when a preoperative magnetic resonance (MR) image of a pelvic schwannoma was suggestive of a lesion in the lower lumbar canal. Definitive studies confirmed the presence of multiple spinal tumors including a thoracic schwannoma, which was removed during a subsequent procedure. This case emphasizes the need to consider the possibility of multiple tumors in every patient presenting with a schwannoma because the follow-up and genetic counseling are vastly different in those with NF2 and schwannomatosis compared with those harboring sporadic tumors. Details of this case and current considerations in the diagnosis and management of schwannomatosis are discussed.