Homogeneous blue pigmentation in dermatofibroma simulating a blue naevus

Area of Science:

• Dermatology
• Dermoscopy
• Histopathology

Background:

• Accurate diagnosis of pigmented skin lesions is crucial for patient management.
• Blue nevi and dermatofibromas are common skin conditions with distinct clinical and dermoscopic features.
• Dermoscopy aids in differentiating benign from malignant pigmented lesions.

Observation:

• A pigmented skin lesion presented with features suggestive of a blue nevus on clinical and dermoscopic examination.
• Histopathological examination revealed the lesion to be a dermatofibroma.
• The dermoscopic finding of homogeneous blue pigmentation, typically associated with blue nevi, was observed.

Findings:

• This case demonstrates that dermatofibroma can exhibit homogeneous blue pigmentation on dermoscopy.
• Dermatofibroma should be considered in the differential diagnosis of lesions with this dermoscopic feature.
• The study defines dermatofibroma as a new exception to the rule for 'homogeneous blue pigmentation' in dermoscopy.

Implications:

• Dermoscopic criteria for diagnosing pigmented lesions require continuous refinement.
• Clinicians should be aware of atypical presentations of common skin conditions.
• This finding may impact diagnostic algorithms and improve the accuracy of differentiating blue nevi from dermatofibromas.