Case 26 Female, 73 years. Fast-growing ulcerating skin tumour, dorsum of footShow diagnosis & comments
Polypoid nodular melanoma.
- Melanoma (usually nodular melanoma) with strikingly exophytic growth pattern
- All or almost all of the tumour is located above the original skin surface
- Often ulceration
- Often considerable thickness
- Prognosis is similar to that of other melanomas, with endophytic growth pattern, when adjusted for major prognosticators such as thickness and presence of ulceration
- Contrary to what is commonly thought, very thick and ulcerated melanomas do not carry a dismal prognosis. See www.melanomaprognosis.org
Note the abrupt changes in cell type, from area to area, in this densely cellular and massive melanoma. This feature, which is also seen in melanoma metastases, is quite typical of melanoma. If such variations for area to area are seen in a metastasis with a nonpigmented large-cell phenotype, the most likely diagnosis (which is usually easily conformed by immunohistochemistry) is: metastatic melanoma.