A rare retroperitoneal schwannoma in a patient with neurofibromatosis Type 2.

Neurofibromatosis Type 2 (NF2) is a dominantly inherited tumour-prone disorder, characterized by the development of multiple schwannomas, meningiomas and ependymomas. Its prevalence is around 1:60 000. Vestibular schwannoma (VS) is the hallmark of NF2. Retroperitoneal schwannomas are expected to occur in only 3% of cases. We present the case of a large retroperitoneal schwannoma in a patient with NF2. A well-circumscribed heterogenic mass (9.5 × 4 × 4 cm) behind and under the left kidney and extending into the left retroperitoneal space was revealed during a lumbar and retroperitoneal space magnetic resonance imaging (MRI). Brain, orbits, cervical, thoracic and lumbar MRI revealed bilateral VS, multiple meningiomas as well as multiple schwannomas and ependymomas in the cervical, thoracic and lumbar spine. The retroperitoneal mass represents a schwannoma probably derived from an intercostal nerve. The patient underwent neurosurgical excision of the VS, and 3 months later, the patient's condition remained stable.