The deep penetrating nevus

Melanocytic nevi and melanoma: unraveling a complex relationship

“…For the purposes of this review, all three types will be considered together. It should be noted that additional types of benign melanocytic nevi such as: blue nevi, 32 Spitz nevi 33 and deep penetrating nevi 34 exist, however, are relatively less common and will not be discussed in detail. Dysplastic nevi will be considered separately below.…”

Deep Penetrating Nevus: A Rare Variant of Melanocytic Nevus

“…Deep penetrating nevus usually affects young individuals [4]. The dermoscopic features of DPN have not been well established [1]. Some authors described asymmetrical, regular, "negative" globular pattern with underlying homogenous blue-brown pigmentation [5] and polychromatic pattern (blue, brown and white) [6].There is still controversy as to whether DPN represents a distinct clinical entity or simply a variant of blue nevus; in addition, DPN has also frequently been found in association with other nevi, thus forming a combined nevus.…”

“…Histopathologically, DPN is a sharply demarcated lesion, and at low power is symmetric and wedged-shaped with a broad base that runs parallel with the epidermis and an apex that is oriented towards the subcutaneous adipose. It consists of often vertically oriented, loose fascicles and nests of spindle-shaped and epithelioid melanocytes extending into the reticular dermis in a plexiform pattern [1].In particular, unlike blue nevi, nevus cells may have a round contour, and are interspersed with scarce melanophages; moreover, compared to other benign melanocytic lesions, nevus cellularity is usually high in DPN [3]. At higher magnification, nevus cells show pleomorphic nuclei with nuclear pseudo-inclusions; mitotic activity is low or absent.…”

“…The earlier reports of DPN discuss is by complete excision. However, perhaps because DPN can clinically and histologically appear similar to malignant melanoma, some clinicians re-excise DPN with margins [1].…”

“…The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life [1]. DPN needs to be distinguished from malignant melanoma and also from other benign lesions as blue nevus, cellular blue nevus, spindle and epithelioid nevus, pigmented spindle cell nevus and congenital melanocytic nevus [2].…”