Diagnosis was established based on morphology and strong nuclear TFE3 immunoreactivity, supported by additional immunohistochemical (IHC) markers including cluster of differentiation 10 (CD10), Melan-A, human melanoma black 45 (HMB45), vimentin, carbonic anhydrase IX (CAIX), and cytokeratins. The gene discussed is CA9; the disease is melanoma.