Metastatic Melanoma With Papillary Features: A Mimic and Possible Diagnostic Pitfall.

Papillary and pseudopapillary features are histopathologic findings typically associated with carcinomas (thyroid, pancreas, breast, prostate, bladder, kidney, or ovary) or mesothelioma. Melanoma is typically composed of nested and variably pigmented atypical cells. Here, we report a case of in-transit metastasis of melanoma presenting with prominent papillary features, and we discuss the differential diagnoses of neoplasms with papillary features. This case report suggests that the spectrum of neoplasms with papillary features should be expanded to include melanoma, a pattern that, to the best of our knowledge, is uncommon.