Key points in the dermoscopic diagnosis of hypomelanotic melanoma and nodular melanoma

Nodular melanoma (NM) and amelanotic/hypomelanotic melanoma (AHM) often present a challenge to the diagnosing clinician. A significant proportion of AHM are nodular in nature. Such tumors may lack features of asymmetry and altered peripheral pigmentation routinely observed in other melanoma subtypes. This lack of distinguishing clinical features can potentially result in delayed diagnosis or inappropriate treatment. This review highlights the key points in evaluating the range of lesions where AHM or NM are considered in the differential diagnosis and summarizes current evidence in relation to pigmented and vascular dermoscopic diagnostic criteria for both.