Infantile myofibromatosis, myofibroma, US, MRI 672
Publication Date: 2005-02-01
Infantile myofibromatosis is, while rare, the most common fibrous tumor in infancy and can occur in the skin, muscle, bone or viscera. Approximately half of the lesions are solitary. One third are multifocal without visceral involvement with the remainder presenting as multifocal disease with solid organ involvement. While most cases occur in infants less than two years of age, they can present in older children or adults.
Prognosis for solitary or multifocal lesions without visceral disease is excellent. Morbidity and mortality in patients with solid organ involvement is usually due to obstruction, failure to thrive, or infection. While myofibromas can occur in any organ system, the cardiopulmonary and gastrointestinal organs are most commonly involved. Skeletal lesions most often occur in the skull and long bones.
US - The ultrasound characteristics of these lesions is variable. Lesions typically are heterogeneous with a predominantly hypoechoic center. Internal vascularity is usually not detected with color Doppler. However, flow can occasionally be detected along the periphery.
MRI - Myofibromas have a very heterogeneous appearance on MR imaging. They typically present as well circumscribed tumors that are predominantly low in signal intensity on T1-weighted images and high in signal intensity on T2-weighted images. With contrast-enhancement, these lesions demonstrate peripheral enhancement, with an appearance suggestive of central necrosis.
- GL Johnson, BL Baisden, EK Fishman. Infantile myofibromatosis. Skeletal Radiol. 1997; 26: 611-614.
- J Dubois, L Garel, M David, J Powell. Vascular Soft-Tissue Tumors in Infancy: Distinguishing Features on Doppler Sonography. Am. J. Roentgenol. 2002; 178: 1541-1545.
- SJ Counsell, C Devile, E Mercuri, JM Allsop, R Birch, F Muntoni. Magnetic resonance imaging assessment of infantile myofibromatosis. Clin Radiol. 2002; 57: 67-70.
- K Koujok, RE Ruiz, RJ Hernandez. Myofibromatosis: imaging characteristics. Pediatr Radiol. 2004; published online Nov 19.