Objective To analyze the PET/CT imaging features of abdominal fibroblastic/myofibroblastic tumors and to improve the understanding of this rare disease.

Methods We collected 28 cases of abdominal myofibroblastic tumors confirmed by operation or puncture pathology. The PET/CT manifestations of the tumors were analyzed. Statistical methods were independent sample t test and homogeneity of variance test.

Results (1) There were 13 cases of aggressive fibromatosis, 10 cases of solitary fibrous tumors and 3 cases of myofibroblastoma in intermediate group and 2 cases of fibrosarcoma in malignant group. 16 cases were located in the abdominal cavity and 12 cases were located in the retroperitoneum with an average diameter of 12.4 cm. (2) PET/CT showed that the main lesions were local fat infiltration or organ invasion. No lymph node metastasis was found in any case, and distant metastasis occurred in 3 cases. (3) The mean SUVmax values of aggressive fibromatosis, solitary fibrous tumors, myofibroblastoma and fibrosarcoma were 4.9, 3.6, 5.6 and 17.9. There was no statistical difference among the first three groups (intermediate type), but they were significantly lower than that of fibrosarcoma (malignant type).

Conclusion PET/CT is helpful for preoperative TNM staging of abdominal fibroblastic/myofibroblastic tumors. SUVmax value is helpful to indicate the malignant degree of tumors.