MRI of soft-tissue masses: the relationship between lesion size, depth, and diagnosis

AIMS: To identify the relationship between depth and size of soft-tissue mass lesions relative to histological diagnosis in a range of malignant neoplastic, benign neoplastic, and non-neoplastic conditions on magnetic resonance imaging (MRI). METHOD: The MRI findings of 571 consecutive patients referred to a supra-regional orthopaedic oncology unit with a suspected soft-tissue neoplasm were reviewed and included in the study. The patient age, histological diagnosis, lesion size, anatomical location, and lesion depth (superficial or deep to fascia) were recorded. RESULTS: There were 288 mates and 283 females (mean age 48 years, age range 2-92 years). The mean age was 54.1 years for malignant neoplastic lesions compared with 40.1 years for benign neoplastic and 45.4 years for nonneoplastic conditions. There was a significant age difference when malignant lesions were compared with benign neoplastic and non-neoplastic lesions (p < 0.001). No significant relationship was present between lesion depth (480 deep, 91 superficial) and diagnosis (288 malignant neoplastic, 197 benign neoplastic and 86 non-neoplastic lesions). However, a significant relationship was identified between lesion size and diagnosis (p < 0.001). Furthermore, a significant relationship was identified when Lesion size greater than 5 cm, lesion depth, and diagnosis were analysed. CONCLUSION: Current guidelines suggest the most important variables for assessing risk of malignancy in a soft-tissue lesion include size, depth in relation to the fascia, increasing size, and pain. The current study suggests that relationship to fascia is less important as a predictor of malignant potential in a patient cohort treated at a supra-regional centre. Significant risk factors include increasing patient age and lesion size greater than or equal to 5 cm. (C) 2007 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.