Trigeminal Nerve Melanotic Schwannoma in Carney Complex

Abstract

Melanotic schwannoma (MS) is a rare peripheral nerve sheath tumor commonly found in the thoracic paraspinal region. It is present in an intracranial location rarely, with 18 out of 105 MS cases described in the literature. Trigeminal nerve was involved in only six of these cases. Fifty percent of psammomatous melanotic schwannoma (PMS) patients have Carney complex. Carney complex is an autosomal dominant disorder featuring peripheral nerve tumors (schwannomas), myxomas (heart, skin, and breast), skin pigmentation (lentigines and blue nevi), and endocrine tumors (adrenal, testicular, and pituitary). We present a case of left trigeminal nerve PMS as a part of Carney complex. Patient had diffuse lentiginosis. Magnetic Resonance Imaging revealed enhancing lesion along left trigeminal nerve with widened Meckel's cave and foramen ovale. Final diagnosis of PMS was derived on clinical, radiological, and histopathological findings with immunohistochemistry correlation. Key Message Trigeminal nerve can be rarely involved in melanotic schwannoma (MS). Knowledge of typical radiological features of MS is crucial for its diagnosis. Its association with Carney complex should be sought.