Differentiation of Benign and Malignant Superficial Soft-tissue Masses Using Grayscale and Color Doppler Ultrasonography

BACKGROUND: This study was performed to evaluate the usefulness of high-resolution grayscale and color Doppler ultrasound to distinguish benign from malignant soft-tissue masses on the basis of ultrasonographic patterns. METHODS: We enrolled 398 female and 420 male patients aged 1-104 years (mean, 49.8 years). All presented with a palpable nodule or mass located superficially in the body. Each lesion was examined by grayscale and color Doppler ultrasonography to assess its echogenicity, margin, shape, composition, acoustic transmission, size and other patterns. Spectral Doppler was applied in lesions with positive color flow signals. The nature of all masses was confirmed by aspiration cytology, biopsy, surgical pathology or long-term clinical follow-up. RESULTS: There were a total of 693 benign and 125 malignant masses. Five malignant and 14 benign histologies (including 6 types with inflammation-related, hematoma or pseudoaneurysm) occurred that had more than 10 subjects with each histology. Eight benign histopathologies included cysts, neoplasms, vascular and miscellaneous. Five malignant histologies included metastases, osteogenic sarcomas, lymphomas, malignant fibrous histiocytomas and liposarcomas. There were significant differences (p < 0.05) between the benign and malignant soft-tissue tumors in terms of parameters including tumor margin, shape and size. Benign lesions did not have infiltrated margins or a scalloped shape and malignant tumors tended to be large. However, there was no significant difference (p > 0.05) between the benign and malignant soft-tissue tumors in terms of echogenicity, composition and color Doppler features. CONCLUSION: Ultrasonography with color Doppler imaging is a good modality for characterizing most soft-tissue masses, and tumor size > 5 cm and having infiltrated margin highly suggests malignancy.