TTF1 and Miyoshi myopathy: Immunohistochemical staining demonstrated that the cytoplasm of the malignant cells was positive for human melanoma black 45 (HMB-45), Melan-A, and S-100 and negative for cytokeratin (CK), CK7, Napsin A, transcription termination factor 1 (TTF1), P40 and P63, confirming the diagnosis of MM (Fig. 3).