ANN R. CUSACKCARRIEMDSENAIT W.DYSONMDJACQUELINE M.JUNKINS-HOPKINSMDVINCENTLIUMDKARLA S.ROSENMANMD
The biopsy findings showed a subcutaneous proliferation with 3 different tissue components: trabeculae of interlacing fibrous tissue, nests or whorls of spindle cells in a mucinous matrix (mesenchymal cells), and mature fat. Fibrous trabeculae, composed of spindle-shaped cells in a densely collagenous stroma, intersected mature fat lobules and nests of immature spindle-shaped to stellate cells in myxoid stroma.
Fibrous hamartoma of infancy (FHI) is a rare, benign, mesenchymal tumor that can occur congenitally or appear during early childhood, with 90% of cases arising within the first year of life.1 The tumor is usually slow growing, although it may initially undergo a period of rapid growth.2 Generally, FHI presents as a painless, freely movable, firm, solitary mass, but cases of multiple synchronous lesions have been reported.3 A solitary lesion may also consist of multiple nodules. Typically, FHI lesions range from 0.5 to 4.0 cm in diameter, but lesions as large as 20 cm have been reported.1 A slight male predominance exists (male to female ratio, 2.4:1).1 The tumor can appear in various anatomic sites, with the most common locations being the axillary regions, upper arms, upper trunk, inguinal region, and external genital regions.1 There does not appear to be a familial relationship. No association with other neoplasms or congenital malformations has been reported.
Bluish Subcutaneous Nodule in a Child—Diagnosis. Arch Dermatol. 2008;144(4):547–552. doi:10.1001/archderm.144.4.547-h