A 10-year-old girl is referred to dermatology for evaluation of an asymptomatic “wart” that manifested on her thigh several years ago. At first, the lesion grew rapidly, but it has since stabilized. It remains unaffected despite multiple treatments with liquid nitrogen.
According to her parents (with confirmation from her medical record), the patient is otherwise quite healthy.
EXAMINATION
A spindle-shaped, pinkish red, 1.2 x 0.7-cm nodule with a smooth surface and rounded borders is located on the patient’s distal left anterior thigh. The lesion itself is quite firm but nontender to the touch, and its long axis is parallel to transverse local skin tension lines. The patient’s type II skin is otherwise unremarkable.
After consultation with the patient and her family, the lesion is excised under local anesthesia with 5-mm margins in an elliptical pattern to yield favorable lines of closure. The sample is sent to pathology.
What is the diagnosis?