Giant Congenital Melanocytic Nevus Coexistent with Chiari II Malformation

Abstract

Giant congenital melanocytic nevus (GCMN) and Chiari II malformation (CM II) are distinct rare clinical entities. No previous report of this condition is to be found in the medical literature. We report the case of a male infant seen initially for a GCMN and an upper thoracic myelomeningocele. MRI incidentally revealed cerebellum and brain stem elongate via the foramen magnum. The infant's physical examination included spastic quadriparesis and hypotonia. An operation for myelomeningocele repair and suboccipital craniectomy with resection of C (1) and cerebellar tonsils was done. The signs and symptoms of the patient were improved after surgery. The GCMN was not treated according to the parents' wished, but a schedule of long-term monitoring was recommended. This case report illustrates that CMNs can coexist with CM II. The clinician who diagnoses a patient with CMNs should remember that this entity can be associated with other pathologies of the central nervous system. Earlier diagnosis and surgical intervention improves the prognosis. Long-term monitoring and follow-up should be recommended for patients with CMNs.