5.4.2.3　Nodular melanoma

Under RCM，nodular melanoma（NM）exhibits several differential features compared with superficial spreading melanoma.These differences are often correlated with dermoscopic and histopathological findings.Within the epidermis，NM lacks characteristics of melanoma such as epidermal disarrangement and pagetoid spreading.Instead，they usually show a honeycomb pattern or a peculiar broadened pattern consisting of polygonal cells with black nuclei and bright and thick borders.At the DEJ，the typical papillary architecture is not visible in the nodules，corresponding to the epidermal flattening caused by massive proliferation of malignant cells in the dermis.Hyporefractive nests，called“cerebriform nests”，are observed in NM，correlating with deep tumor infiltration.Plump cells are present and correlated with dermal macrophages，usually associated with a moderate degree of inflammation.(https://www.daowen.com)