CT and MRI features of adult rhabdomyosarcoma of the extremities / 中国医师进修杂志

ABSTRACT

Objective@#To investigate the CT and MRI features of adult rhabdomyosarcoma (RMS) of extremities.@*Methods@#A retrospective analysis was carried out on CT and MRI findings of 10 patients with rhabdomyosarcoma of extremities confirmed by surgery and pathology in Wenzhou People′s Hospital and the Second Affiliated Hospital of Wenzhou Medical University. The site, size, shape, margin, density or signal, adjacent tissue changes and enhanced degree of the mass were observed.@*Results@#In the 10 cases, the mass was located in the thigh in 6 cases, in the calf in 3 cases, and in the upper arm in 1 case. The maximum diameter of the tumor was 2.9-22.5 (12.0 ± 7.2) cm. The masses were oval in 2 cases and irregular in 8 cases. The margins of the masses were clear in 2 cases and unclear in 8 cases. There was invasive destruction of adjacent bone in 3 cases, intratumoral necrotic cystic changes in 8 cases, intratumoral hemorrhage in 2 case, and lymph node metastasis in 3 cases. Four patients underwent plain CT scan CT presented isodensity in 1 case and slightly lower density in 3 cases. The mass density was uniform in 1 case and uneven in 3 cases. CT value of the solid part of the mass was 27-47 (42 ± 6) HU in average. Three patients underwent enhanced CT scan all the enhanced masses showed uneven enhancement, including 1 case of mild enhancement and 2 cases of moderate enhancement, with no enhancement of necrotic cystic lesion area and clear in lesion boundary. Nine patients underwent plain MRI scan mass of 9 cases presented iso-signal or slightly lower signal on T1WI, including 4 cases with iso-signal and 5 cases with slightly lower signal. There were 7 cases of uneven signals and 2 cases of uniform signals. The mass presented high signal on T2WI, including 8 cases with uneven signals and 1 case with uniform signals, and the necrotic cystic lesion showed higher signal on T2WI. Seven patients underwent enhanced MRI scan all the enhanced masses showed uneven enhancement, including significant enhancement in 5 cases, moderate enhancement in 2 cases, no enhancement in necrotic cystic lesion area, and "perivascular" phenomenon in 4 cases.@*Conclusions@#CT or MRI examination shows that the soft tissue tumor of the extremities presents low density on CT, equal or slightly low T1WI signal on MRI, and high signal on T2WI, with necrotic cystic lesion inside peripheral blood vessel density in the tumor, without calcification and significantly or moderately uneven enhancement should consider the possibility of RMS should be considered.