This study was designed too identify the MR histoanatomical distribution of soft-tissue tumors.

A total of 290 soft-tissue tumors of 281 patients were analyzed by the use of MR imaging and were pathologically confirmed after surgical resection or a biopsy. There were 120 malignant soft-tissue tumors including tumors of an intermediate malignancy and 170 benign tumors. The histoanatomical locations were divided into three types: 'Type I' with superficial layer tumors that involved the cutaneous and subcutaneous tissue, 'Type II' with deep layer tumors that involved the muscle or tendon and 'Type III' with soft-tissue tumors that involved both the superficial and deep layers.

Soft-tissue tumors with more than three cases with a frequency of more than 75% included dermatofibrosarcoma protuberans, glomus tumor, angiolipoma, leiomyosarcoma and lymphoma as 'Type I' tumors. 'Type II' tumors with more than three cases with a frequency of more than 75% included liposarcoma, fibromatosis, papillary endothelial hyperplasia and rhabdomyosarcoma. 'Type III' tumors with more than three cases with a frequency of more than 50% included neurofibromatosis.

The MR histoanatomical distributions of soft tissue tumors are useful in the differential pathological diagnosis when a soft-tissue tumor has a nonspecific MR appearance.