A 12-year-old boy presents with multiple dark, irregularly bordered hairy patches on the upper back and shoulders present since early childhood. The lesions have become more raised and hairy over recent years. There are no other systemic findings. What is the diagnosis?
- A Café-au-lait spots of neurofibromatosis type 1
- B Congenital melanocytic nevus (bathing trunk nevus variant)
- C Becker nevus ✓
- D Pigmented epithelioid melanocytoma
Correct answer: C. Becker nevus
Explanation
Becker nevus presents in childhood or adolescence as a unilateral, hyperpigmented, irregularly bordered patch that gradually becomes hypertrunk, usually on the shoulder or upper chest. It is a benign hamartoma. Neurofibromatosis type 1 requires six or more café-au-lait spots greater than 5 mm in prepubertal children and they are smooth, not hairy or raised. Bathing trunk nevi are large congenital melanocytic nevi present at birth.
Reference: Andrews' Diseases of the Skin: Clinical Dermatology, 13th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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