Congenital Nevi Differential Diagnoses

Updated: Apr 24, 2019
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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Diagnostic Considerations

Also consider the following:

The histopathologic interpretation of proliferative nodules (PNs) in congenital melanocytic nevi can be challenging, as some PNs may exhibit atypical features that make the distinction from melanoma difficult. [28] Histologic features and Ki-67 and PHH3 expression levels were found to be the best parameters to distinguish between benign versus atypical PNs, which appear to be borderline between benign PNs and dermal melanomas. It can be difficult to differentiate between benign and malignant proliferation in infants with secondary melanocytic proliferation. [29] Giant congenital melanocytic nevi with solid tumors within them presenting at birth are unusual; a variety of malignancies may occur within these masses. [30, 31]

A giant congenital melanocytic nevus with vascular malformation and epidermal cysts, associated with a somatic activating mutation in BRAF, has been described. [32]

Differential Diagnoses