Liposclerosing myxofibrous tumor: radiographic reporting frequency, pathologic correlation, and malignant...

To analyze the experience at our institutions with liposclerosing myxofibrous tumor (LSMFT) regarding radiographic reporting, pathologic correlation, and follow-up for malignant transformation.

A retrospective search of imaging and pathology databases at two tertiary institutions (1987-2022) identified cases with LSMFT in the diagnosis or differential diagnosis. Clinical records, imaging reports, and follow-up data were reviewed. Two fellowship-trained musculoskeletal radiologists independently assessed imaging features and two bone tumor pathologists independently reviewed the pathology findings.

Among over 11 million imaging reports, 149 cases included LSMFT in the imaging report differential diagnosis, with pathologic correlation available in 18 patients (8 men, 10 women; median age 41.9 years [range, 16.5-68.3 years]). All patients presented with hip pain. Radiography was performed in all 18 cases, CT in 7 cases, and MRI in 15 cases. On imaging, lesions appeared well-defined with a sclerotic margin (14/18) and were most commonly central (14/18) and intertrochanteric (16/18) in location. Mean diameter was 5.9 cm in greatest dimension (range, 3.2-11.5 cm). Histopathology revealed low-grade benign neoplastic and non-neoplastic lesions in all cases, most commonly fibrous dysplasia (9/18). Two out of 18 cases were found with LSMFT in the pathology report impression. No malignant transformations were observed on follow-up.

When radiography shows findings described as possible LSMFT, the pathology diagnosis generally corresponds to other benign lesions. No malignant transformations were observed in our cohort. In the absence of symptoms or aggressive imaging features, we do not routinely pursue surveillance cross-sectional imaging, biopsy, or surgical management.