Lipofibromatosis arising in a pediatric forearm--a case report.

Lipofibromatosis is a rare pediatric tumour described by Fetsch et al. in 2000. There have been few reports about this tumour and few descriptions of its imaging features. We report a case of this tumour forming a slowly growing, painless mass arising in the forearm of a ten-month-old boy. This is the first report of lipofibromatosis to present the radiological findings before surgery. Plain radiography and computed tomography demonstrated a tumour located just beneath the fascia. Ultrasonic study showed a hyperechoic tumour of 33 x 30 x 7 mm in size. Magnetic resonance imaging demonstrated a multilobular mass with high signal intensities on both T1/T2 weighted images. Macroscopically, the tumour was poorly marginated. Microscopically, the tumour was composed of abundant adipose tissues transversed by fibroblastic bands. The adipose tissue occupied over 70% of the tumour. Adipocytes and fibroblastic element infiltrated into the normal skeletal muscle tissues. Recognition of this clinical entity is needed, especially in cases of lipomatous tumours arising in pediatric hands and feet.