Visual Diagnosis

Presentation

A 10-year-old boy who has multiple hyperpigmented spots on his skin and a deformed left forearm since birth presents to a tertiary care center for additional evaluation. He was born at term via vaginal delivery. He has been healthy except for functional and cosmetic problems related to his deformed left forearm. The family resides in a locale that lacks advanced health-care services. In the past, a local health practitioner informed the family that their child's skin lesions and limb deformity were congenital and no treatment was available. No surgical correction has been attempted. However, recent evaluation by a pediatrician prompted referral to the tertiary care center. The child has no history of developmental delay, and his school performance is average for age. His vision and hearing are normal. His parents are first cousins, and he has four healthy siblings. Family history is otherwise unremarkable, with no history of multiple hyperpigmented skin lesions or limb deformities.

Physical examination reveals an alert, short, and underweight child whose facies are normal. His weight is 21 kg (∼5th percentile), height is 124 cm (∼5th percentile), and head circumference is 52 cm (50th percentile). All vital signs are normal. Skin examination reveals multiple hyperpigmented skin macules of variable sizes and shapes scattered over the trunk, back, and upper and lower limbs (Fig. 1). Two palpable, firm skin nodules measuring 1×2 cm are present on the lateral aspect of his neck and back. Eye examination suggests raised spots on the irises. Examination of the hair, nails, ears, nose, throat, chest, heart, abdomen, and genitalia yields normal results. Musculoskeletal examination reveals marked bowing of the left forearm, although the hand and digits appear normal (Fig. 2). Results of the neurologic examination are unremarkable.