Soft-tissue inflammatory myofibroblastic tumors (IMTs) of the limbs: potential and limits of diagnostic imaging

OBJECTIVE: The objective of this work was to evaluate the potential of diagnostic imaging in the identification, localization, and characterization of soft-tissue inflammatory myofibroblastic tumors (IMTs) of limbs with correlation to differential diagnosis and therapy. MATERIALS AND METHODS: From a retrospective analysis of 324 histologically verified soft-tissue lesions of limbs and extremities diagnosed in our institute from January 2002 to July 2010, we selected seven cases of histologically proven IMT. These included six males and one female, aged between 28 and 81 years (mean age, 57 years). Lesions were localized in three cases to the thigh, in two cases to the popliteal space, and in the remaining two cases, to the shoulder girdle. All patients were evaluated on the basis of US, CT, and MRI. RESULTS: Ultrasound detected the presence of a non-homogeneous solid formation in all cases and calcifications in three cases. CT showed the presence and type of calcification/ossification and bone reaction. On MRI, all cases had low signal intensity on SE T1-weighted sequences and an intermediate-low signal intensity on SE and FSE T2-weighted sequences in six of them; only one case had an intermediate-high signal intensity on SE and FSE T2-weighted sequences. Both contrast-enhanced CT and MRI showed precocious enhancement in association with multiple peripheral hypertrophic blood vessels. CONCLUSIONS: On the basis of integrated imaging data obtained by US, CT, and MRI, it is possible to evaluate the lesion extension to provide a loco-regional staging, to characterize IMTs, and to allow an optimal therapeutical planning.