Vascular neoplasm or pseudovascular nevus? Potential pitfalls in diagnosis

Melanocytic nevi, on histopathologic evaluation, occasionally contain slit-like clefts or spaces that may resemble vascular or lymphatic spaces. The spaces may contain blood or, perhaps more concerning, nests of melanocytes that could suggest lymphatic invasion of melanoma. When lined by melanocytes rather than true endothelium, these pseudovascular spaces within melanocytic nevi are generally attributable to tissue processing artifact. When the space in question is pronounced, a proper diagnostic work-up is prudent in order to exclude a true vascular neoplasm or melanoma. In this case series we present several melanocytic lesions with prominent vascular-appearing spaces that warranted further investigation.