Nodular melanoma
- Aggressive skin cancer that arises in melanocytes
- Like Merkel cell cancer, nodular melanoma enlarges rapidly and may be blue, red, or flesh-colored
- Commonly occurs in people who are immunocompromised and is associated with sun exposure
- Unlike Merkel cell cancer, nodular melanoma may occur in patients of any age and is seldom located on the face
- Differentiated from Merkel cell cancer by histopathologic characteristics and by immunohistochemical staining of primary lesion
- In most patients with melanoma, immunohistochemical markers HMB-45 and NKI/C3 are positive and cytokeratin 20 is negative
