A case of nodular fasciitis in a child

comparison with an adult case and 28 cases of children reported in Japan

Abstract

Case: An 8-year-old boy with no history of trauma presented with a lump on his right lumbar back that had appeared 1 week before. The lump was a 12 × 10 mm flat nodule with a smooth surface and good mobility and could be moved against the foundational structure. At the 4-month follow-up, the lump had expanded to 20 mm. A biopsy revealed a relatively well-defined basophilic region from the deep dermis to the superficial subcutaneous fat. The lesion mostly comprised spindle-shaped cells, with dense and substantial nuclei in the darkly stained areas, a storiform or cartwheel distribution in the lightly stained areas, as well as sparse mitotic figures, lymphocytic infiltration, and extravasated red blood cells. The fatty tissues were not divided into honeycomb-like sections, but increased in a compressible manner. It was strongly positive for α-SMA, but negative for Desmin, ALK, S100, CD34, and Factor XIIIa; thus, the diagnosis of nodular fasciitis was made. The nodule all but disappeared 5 months after the biopsy, and no recurrence was observed for 1.5 years. Nodular fasciitis is a benign lesion characterized by rapid growth and often spontaneous resolution. In children, the mean age of onset was 8.3 years, slightly more common in boys, and the predominant site of onset was the head and neck region. Nodular fasciitis should be considered when examining rapidly growing subcutaneous nodules, even in children.