Featured Student: Manisha Vadali

Manisha Vadali is a second-year medical student at the University of Missouri-Kansas City School of Medicine. Her work on a case report about neurocutaneous melanosis deepened her knowledge of rare dermatologic disorders and the intricacies of presenting pediatric cases, particularly in dermatology. Manisha is especially drawn to pediatric dermatology with a focus on addressing the needs of skin of color and underserved communities. Beyond her medical studies, she finds joy in practicing hot yoga and watching Shark Tank.

Neurocutaneous melanosis (NCM) is a rare congenital disorder characterized by melanocytic nevi, leptomeningeal melanosis, and severe neurological complications. Malignant transformation of leptomeningeal melanosis is associated with poor prognosis due to its aggressive progression and resistance to treatment.

This case report describes an 18-month-old boy with NCM, who presented with altered gait, recurrent falls, and neurological deficits, including hyperreflexia, bilateral Babinski signs, and reduced lower limb sensation. Imaging revealed a 4 cm intradural extramedullary mass in the lumbar region, causing significant syringohydromyelia and spinal canal compression.

Histopathological analysis of the mass confirmed malignant melanoma, with large, atypical cells showing high mitotic rates. Immunohistochemistry was positive for Melan-A, HMB-45, and vimentin, consistent with the primary cutaneous lesions.

Cytogenetic studies identified genetic alterations, including a loss of PTEN and RAD51B genes and an NRAS Q61K mutation, which supported targeted therapy with a MEK inhibitor (trametinib). Despite initial treatment, the patient developed new metastatic lesions within two months, necessitating a switch to immunotherapy with ipilimumab and nivolumab. Surgical resection was attempted but was incomplete due to the infiltrative nature of the tumor. The disease progressed rapidly, and the patient passed away 163 days after diagnosis.

This case underscores the aggressive nature of NCM-associated melanoma and the challenges posed by its invasive growth patterns and genetic complexity. Current therapeutic strategies, including MEK inhibitors and immunotherapy, have limited efficacy in such cases. This highlights the need for further research to identify novel therapeutic targets, develop effective treatments, and refine diagnostic protocols to improve outcomes in this devastating pediatric condition.