Purpose: When evaluating superficial soft tissue masses with ultrasound, it is not always easy to determine cystic or solid nature. We reviewed sonograms of soft tissue tumors interpreted as cystic but confirmed as solid.
Materials and Methods: We scanned database of patients with superficial soft tissue masses from 2 different institutes. Lesions were evaluated on ultrasound and then confirmed surgically. 25 out of 431 masses were selected, of which initial interpretation was cystic or included cystic tumor and its pathology was solid tumor. All images were reviewed by two radiologists, regarding internal echogenecity of lesions, presence of posterior enhancement, margin, size, and internal vascularity.
Results: Twenty five masses were proven as benign fibrous histiocytoma (n = 2), fibroma and GCT of tendon sheath (n = 5), fibromatosis (n = 2), dermatofibrosarcoma protuberans (n = 2), dermatofibroma (n = 1), schwannoma (n = 4), angioleiomyoma (n = 3), granular cell tumor (n = 2), one of eccrine spiroadenoma, granulation tissue, lymphoma, myeloma. Masses were hypoechoic in 16 (homogenous in 10, heterogenous in 6), anechoic in 6 and isoechoic in 3. Posterior enhancement was present in 12 masses and 8 of them showed no internal vascularity on color Doppler images. Margin was smooth in 10, smooth with mild lobulation in 10 and lobulated in 5. Mean size was 2.09 cm.
Conclusion: Of cyst-like solid masses on ultrasound, fibrous tumor was the most frequent. Care should be given to these solid tumors that have cystic appearances even without internal vascularity on Doppler imaging.