Evaluate for soft tissue infection. Check deep spaces given contusion of left thigh, subsequent encounter Overall the heterogeneous and ill-defined soft tissue mass in the areas previously described by both CT and MR appears similar to mildly enlarged, specifically the morning or chronic components have minimally increased since 9/25/2015 and mild areas of involvement since the prior MR only evaluating the lower pelvis and upper most thigh. The mass margins remain poorly defined and difficult to measure axially consistently, yet when compared to the prior CT at the level of the upper thigh and area of scattered calcifications, again the mass roughly measures 10 x 9 cm with increased extension and involvement into the left subcutaneous tissues and fat underlying the midline crease (image 21 series 19). Interval increased necrotic and cystic components are again observed inferior to the ischial tuberosity and for reference the 9 x 3 cm collection currently measures 13 x 4 cm (image 19 series 20).Similar mild enlargement of the lobulated cystic and necrotic component centered in the abductor magnus musculature, remains mildly more discrete in margin and currently measures 5.3 x 4.7 cm (image 6 series 40) with mild peripheral enhancement, previously 4.5 x 3.4 cm. The overall pattern of enhancement and signal abnormality begins supports tumor invasion as apposed to specific signs of infection such as gas. Again diffuse subcutaneous reticulation and skin thickening is observed throughout the left thigh, of uncertain significance and although tumor invasion cannot entirely be excluded, this may be possibly related to radiation therapy; please correlate. This larger fluid collection in the abductor magnus however would be readily accessible if sampling was needed clinically.
Persistent redemonstration of heterogeneous ill-defined soft tissue mass throughout the left groin demonstrating mild interval minimal enlargement but largely enlarging central to chronic cystic components. See measurements provided. Overall appearance again remains compatible with known sarcoma and possible interval posttreatment changes. Specifically no discrete new findings to support concern for focal infection, however given tumor characteristics and appearance, specificity and exclusion is difficult to confirm.