Late onset dermal melanocytosis: an upper back variant

Area of Science:

• Dermatology and Pathology
• Histopathology of Skin Lesions
• Melanocyte Biology

Background:

• Pigmented skin lesions can manifest in various forms across different demographics.
• Understanding the cellular origin of dermal pigmentation is crucial for diagnosis.
• Late-onset pigmentary conditions require further investigation and classification.

Observation:

• Seven elderly Japanese men presented with distinct blue macules localized to their upper backs.
• Clinical observation of the macules' color and distribution.
• Patient demographic data focusing on age and ethnicity.

Findings:

• Histological examination revealed melanosis, characterized by spindle-shaped or oval pigment-laden cells within the dermis.
• Electron microscopy confirmed these cells are consistent with dermal melanocytes.
• The findings support a diagnosis of dermal melanocytosis.

Implications:

• This study proposes a novel variant of late-onset dermal melanocytosis, specifically affecting the upper back.
• This finding expands the known spectrum of dermal melanocytosis and its clinical presentations.
• Further research may elucidate the specific etiology and pathogenesis of this upper back variant.