Invasive basal cell carcinoma with metaplastic bone formation associated with a long-standing dermatofibroma

Area of Science:

• Dermatopathology
• Oncology
• Skeletal Biology

Background:

• Basal cell carcinoma (BCC) is the most common skin cancer.
• Dermatofibromas are common benign skin tumors.
• Metaplastic ossification is rare in skin lesions.

Observation:

• A nodule present for many years on the right leg of a 77-year-old woman was surgically removed.
• Microscopic examination of the excised nodule was performed.

Findings:

• The diagnosis was invasive keratinizing basal cell carcinoma.
• The BCC was found to arise within a pre-existing dermatofibroma.
• Metaplastic bone formation was observed within the tumor.

Implications:

• This case highlights a rare association between basal cell carcinoma and dermatofibroma.
• The presence of metaplastic bone in this context is unusual and warrants further investigation.
• Understanding these rare presentations is crucial for accurate diagnosis and patient management in dermatopathology.