[Nested melanoma]

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Nested melanoma is a recently described entity, first reported in 2012.
• It is characterized by specific clinical, dermatoscopic, and histopathological features.
• This study aims to highlight criteria for this melanoma subtype.

Observation:

• A 52-year-old male presented with a large, irregular, and discolored pigmented lesion on his chest.
• Dermatoscopy revealed a chaotic pattern with a structureless black area, peripheral globules, and segmental radial lines.
• Histopathology showed an asymmetric lesion with large junctional melanocytic nests, focal gathering, and cytological atypia.

Findings:

• Nested melanoma is a distinct anatomoclinical variant of superficial spreading melanoma.
• Clinically, lesions are typically large and found on sun-damaged skin, though not exclusive to the elderly.
• Key dermatoscopic findings include a globular pattern, alongside features of superficial spreading melanoma.

Implications:

• Histological diagnosis can be challenging, mimicking benign nevi due to the nested pattern.
• Distinguishing features include large, atypical junctional nests, bridging, and lesion asymmetry.
• Recognizing these specific criteria is vital for accurate diagnosis and management of nested melanoma.