Race for the Case

Race for the Case is a clinical quiz feature published quarterly in DermWorld Directions in Residency — and right here!

Answer the questions below to enter. Looking for the Winter 2022 answers? Review them now. To submit cases and questions, email Dean Monti at dmonti@aad.org.

Diagnose this case by Eduardo Michelen Gómez, MD and Karina Cancel-Artau, MD

A 39-year-old male patient with a history of intellectual disability, hydrocephalus with ventriculoperitoneal shunt since the age of three, and epilepsy was admitted for a three-day history of tonic-clonic seizures and multiple bouts of dark brown-colored emesis. At the time of admission, he denied any other systemic symptoms. Spine and brain MRI showed diffuse supratentorial and infratentorial leptomeningeal thickening and enhancement with intrinsic T1 hyperintensity involving the basal cisterns and bilateral frontoparietal lobes. On day two of his hospital stay, the inpatient dermatology service was consulted for evaluation of multiple brown cutaneous lesions. Physical examination was remarkable for the presence of widespread, “velvety” appearing, brown plaques that involved the head, neck, trunk, and extremities, most of which also had overlying tufted hairs. No alarming gross or dermatoscopic features were identified. A 4-mm punch biopsy of a single lesion showed regular nests of melanocytes in the dermoepidermal junction and upper reticular dermis.

1. What is the most likely diagnosis and most common mutation?

2. Which postzygotic genetic mutation is most likely present and associated with the development of the cutaneous lesions in this patient?

3. What are the most common extracutaneous findings associated with this condition?

4. Mention some of the CNS structural abnormalities.

Related Academy resources