Melanoacanthoma: a potential pitfall of reflectance confocal microscopy
Ana Carolina Souza Porto1, Tatiana Pinto Blumetti1, Mariana Petaccia de Macedo1
1Cutaneous Oncology Department, AC Camargo Cancer Center, São Paulo, SP, Brazil.
Anais Brasileiros De Dermatologia
|December 3, 2019
Summary
Melanoacanthoma, a rare seborrheic keratosis variant, presents diagnostic challenges due to its dark pigment and rapid growth. This case highlights the importance of histopathology for accurate diagnosis of this benign skin lesion.
Area of Science:
- Dermatology
- Dermatopathology
Background:
- Melanoacanthoma is a rare variant of seborrheic keratosis.
- It is characterized by dark pigmentation and rapid radial growth.
- Distinguishing melanoacanthoma from melanoma can be challenging.
Observation:
- A scalp lesion with fast growth was observed.
- Dermoscopy and confocal microscopy suggested dendritic cell proliferation.
- The lesion's appearance made clear benign classification difficult.
Findings:
- Histological examination revealed proliferation of keratinocytes and dendritic melanocytes.
- Immunohistochemical staining confirmed the diagnosis.
- The lesion was histopathologically consistent with melanoacanthoma.
Implications:
- Accurate diagnosis of melanoacanthoma is crucial to avoid unnecessary treatment for melanoma.
- Dermoscopy and confocal microscopy can aid in the in vivo assessment of such lesions.
- Excision and subsequent histopathologic evaluation remain the gold standard for definitive diagnosis.
