18F-FDG PET/CT and MRI features of myxoid liposarcomas and intramuscular myxomas.
Skeletal Radiol 2018;
47:1641-1650. [PMID:
29926115 DOI:
10.1007/s00256-018-3000-y]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/30/2018] [Accepted: 06/01/2018] [Indexed: 02/02/2023]
Abstract
OBJECTIVE
To examine the imaging characteristics of intramuscular myxomas (IM) and myxoid liposarcomas (MLS) on 18F-FDG PET/CT and MRI.
MATERIALS AND METHODS
With IRB approval, our institutional imaging database was searched for pathologically proven IM and MLS evaluated by 18F-FDG PET/CT and MRI. PET/CT and MRI imaging characteristics were recorded and correlated with pathologic diagnosis.
RESULTS
We found eight patients (2 M, 6 F) with IM (mean age 65.6 ± 10.4 years) and 16 patients (7 F, 9 M) with MLS (mean age 42.8 ± 16.3 years). MRI was available in 7/8 IM and 15/16 MLS patients. There was no significant difference between the two groups in SUVmax (IM 2.7 ± 0.8, MLS 3.0 ± 1.0; p = 0.35), SUVmean (1.7 ± 0.4, 1.5 ± 0.5; p = 0.40), total lesion glycolysis (101.8 ± 127.3, 2420.2 ± 4003.3 cm3*g/ml; p = 0.12), metabolic tumor volume (62.3 ± 71.1, 1742.9 ± 3308.0 cm3; p = 0.17) or CT attenuation (p = 0.70). MLS occurred in younger patients (p = 0.0015), were larger (16.4 ± 8.2 vs. 5.6 ± 2.5 cm; p = 0.0015), more often T1 hyperintense (p = 0.03), with nodular enhancement (p = 0.006), and macroscopic fat on CT (p = 0.0013) and MRI (p = < 0.001) compared to myxomas.
CONCLUSIONS
IM and MLS most commonly demonstrate low-grade FDG activity and overlapping metabolic measures on PET/CT. MRI is useful in differentiation, but MLS can present without macroscopic fat on MRI, underscoring the importance of radiologic-pathologic correlation for accurate diagnosis.
Collapse