PMEL and neoplasm: Some ONB can show focal melanin pigment and rare positivity for HMB-45 but positivity for neuroendocrine markers, negativity for Melan-A and careful interpretation of Masson Fontana rules out sinonasal melanoma.14,23 Lymphoma can show wide spectrum of morphologic features but these neoplasms exhibit a usual diffuse sheet-like growth pattern and positivity for CD45.6 Sinonasal Paraganglioma (SP) is also a benign mimic of ONB which also exhibits a nesting pattern of tumor cells with positive neuroendocrine expression and surrounding S100 positive sustentacular cells.