Inflammatory myofibroblastic tumor (IMT) is a rare tumor with low-grade malignant risk mainly occurring in soft tissues and lungs, and it is extremely rare in the breast. Meanwhile, imaging findings of the tumor often present with non-specific features that lead to misdiagnosis and delayed treatment. Here, we report a case of inflammatory myofibroblastic tumor in the breast with the imaging findings of mammography, magnetic resonance imaging (MRI), and pathologic findings to improve the understanding of the disease. The patient was treated by surgical operation, and was followed up for 44 months, no local recurrence and distant metastasis.

Rhabdomyosarcoma (RMS) is a common malignancy in children, but embryonal rhabdomyosarcoma (ERMS) deposits rarely occur in the breast in adults. Therefore, little is known about magnetic resonance imaging (MRI) features of breast metastases from RMS, especially the embryonal type. We reported a case of a 22‐year‐old woman who was diagnosed with ERMS at left foot 2 years ago and accepted operation and chemotherapy. She was confirmed to have breast metastases from the left foot. Successive imaging examinations were performed 3 months apart. Breast ultrasound indicated a benign lesion, and further examination did not reveal any bone metastases. However, predominant restricted diffusion and rim contrast enhancement on MRI combined with the patient's medical history suggested a malignancy of BI‐RADS 5. After 3 months, breast ultrasound revealed masses detected last time became larger and lobulated. In addition, internal heterogeneous intensity and rim contrast enhancement with restricted diffusion were revealed on MRI. We speculated that typical MRI findings of breast metastases from RMS may include iso‐ to hypointensity on T1WI, heterogeneous hyperintensity on T2WI, and circular enhancement with restricted diffusion. Moreover, mild peritumoral edema, rapid expansion of necrosis, and ascending time‐intensity curve detected on MRI may be features of the ERMS type.