FIBROMATOSIS COLLI OF INFANCY - VARIABILITY OF SONOGRAPHIC APPEARANCE

Purpose. We describe the variable sonographic appearances of fibromato sis colli, a disease that presents as a mass-like enlargement of the s ternocleidomastoid muscle during the first 8 weeks of life. Methods. S onograms and records of 12 infants who presented with a sternocleidoma stoid mass or torticollis before they were 12 weeks old were retrospec tively reviewed for sonographic features (presence of a mass, diffuse muscle enlargement, and echogenicity), medical history, and follow-up data. Results. Sonographically, 6 infants had on ly a mass in the ster nocleidomastoid muscle, 2 had a mass with fusiform muscle enlargement, and 4 had only muscle enlargement. Five masses were hyperechoic, and 1 mass was of mixed echogenicity. The 2 masses associated with muscle enlargement were hypoechoic. Three cases of diffuse muscle enlargement were of mixed echogenicity, and 1 was hypoechoic. Unusual variations included (1) a mass split longitudinally into 2 components and (2) a d iffusely enlarged muscle with a striated pattern of mixed echogenicity . Followup in 10 patients at 4 months and in 7 patients at 6 months sh owed clinical improvement. Conclusion. Fibromatosis colli usually appe ars sonographically as a hyperechoic mass or diffuse sternocleidomasto id enlargement of mixed echogenicity. Variations in its appearance sho uld not prevent the correct diagnosis as long as the abnormality is in tramuscular and adjacent soft tissues are normal. (C) 1998 John Wiley & Sons, Inc.