= infantile fibromatosis of nondesmoid type

= rare fibrofatty tumor of childhood

Histo: mass with abundant adipose tissue traversed by bundles of spindle-shaped fibroblasts

Location: hand + foot >head & neck, chest wall, abdominal wall, jaw

Median age: 1 year (range, 11 days to 12 years); present at birth in 18%; M÷F = 2÷1

• slow-growing painless subcutaneous mass

Median size: 2 (range, 1–10) cm

MR (modality of choice):

• mass isointense to fat interspersed by low- to intermediate SI (= fibrous component) on all sequences:
  • infiltrative toward subcutaneous + deeper soft tissues
  • ± enhancement of fibrous component