Cutaneous malignant melanoma associated with extensive pseudoepitheliomatous hyperplasia. Report of a case and discussion of the origin of pseudoepitheliomatous hyperplasia.

We report a case of cutaneous malignant melanoma associated with extensive pseudoepitheliomatous hyperplasia. Pseudoepitheliomatous hyperplasia may mimic squamous cell carcinoma and may complicate the diagnosis of cutaneous melanoma. This diagnostic pitfall is important to both recognize and be cognizant of, so as to avoid diagnostic errors. The observation of the pseudoepitheliomatous hyperplasia, in this case with an extensive proliferation of eccrine ducts, provides further evidence that cutaneous pseudoepitheliomatous hyperplasia arises within the eccrine apparatus.