Clinical Findings: A 28 years old woman presented with a 1.3 x 0.7 cm darkly pigmented lesion on the left lateral side of neck. She recalled this lesion has been there since her birth. She did not feel any recent change in size or irritation symptoms. Dermatologist was suspicious of melanoma and a punch biopsy was performed.
Pathological findings; At scanning magnification, sections showed the relatively sharply demarcated, intensely pigmented and wedge-shaped configuration of the lesion, which extends through the full thickness of dermis into the subcutis in the center of the lesion. No obvious maturation of melanocytes was noted. There were a few junctonal melanocytic components with no remarkable atypia. A discontinuation of the lesion in the papillary dermis was also seen, mimicking a “Grenz zone”. The dermal component was composed of loose nests and vertically oriented fascicles of epithelioid and short-spindled melanocytes. The epidermoid morphology was more frequent in the upper parts of the lesion and the spindled ones predominant in the deeper parts. Melanophages, dendritic melanocytes and mild inflammatory cells were also admixed. The melanocytes extended along skin adnexa and perivascular spaces without destroying them. The subcutis extension of these melanocytes was closely associated with this adnexal extension. The melanocytes showed small to medium-sized nuclei with irregular nuclear contour, inconspicuous nucleoli and relatively even chromatin pattern. No mitosis was identified in any of dermal component. Double Immunohistochemical study with MART- 1 and Ki67 also demonstrated no double-positive melanocytes in the dermal components, indicating as a low proliferative activity.
Treatment; A conservative complete excision of any residual pigment lesion was performed.