Pseudo‐melanoma revealing Laugier‐Hunziker syndrome

A 47‐year‐old Arabic woman presented with a few months history of a 20 × 10 mm brown‐black interdigital macule, irregular in shape and outline (Fig. 1). The patient had no previous personal or familial history of dysplastic nevi, melanoma, or gastrointestinal polyposis. She was receiving fluindione, furosemide, digoxin. and lisinopril dihydrate for chronic atrial fibrillation. She had a mitral valvular bioprothesis secondary to rheumatic heart disease. On physical examination there were no enlarged lymph nodes. Multiple pigmented macules were noted on the lower lip and buccal mucosa (Fig. 2). Genital mucosa showed no pigmentary abnormalities. There were also many pigmented longitudinal streaks involving five finger‐ and two toenails without Hutchinson's sign, two brownish interdigital macules of the fingers (Fig. 3), and dark brown spots around the nails. Clinical examination of her two sisters and three children did not demonstrate mucocutaneous pigmentation. Investigations showed normal renal, hepatic, and thyroid function. Human immunodeficiency virus serology was negative. Two‐punch biopsy 4×4 mm of the right darkness and left edges of the interdigital lesion confirmed the diagnosis of Laugier‐Hunziker syndrome with basal hypermelanosis without melanocytic proliferation or cytologic atypia (Fig. 5). After 2 years follow‐up, clinical and histologic examination was not modified.