Imaging findings of inflammatory myofibroblastic tumor in breast: A case report

RATIONALE: Inflammatory myofibroblastic tumors (IMTs), particularly breast IMTs, are rare neoplastic lesions typically associated with a favorable prognosis. Breast IMTs are easily misdiagnosed as other types of malignant lesions, and therefore there is a significant unmet need for a better preoperational differential diagnosis based on imaging manifestations. Here, we report the imaging findings of a breast IMT and compare our findings with previously published features of breast IMTs. PATIENT CONCERNS: The patient, a 43-year-old female, reported the presence of a palpable lump within her left breast. An ultrasound examination revealed an irregular hypoechoic mass with unclear boundaries. Mammography demonstrated a mass of heterogeneous and striped density with granular calcification. Magnetic resonance image (MRI) inspection displayed an irregular tissue lump with an undistinguishable boundary and a further dynamic contrast-enhanced MRI disclosed an associated efflux change. DIAGNOSES: Breast inflammatory myofibroblastic tumors. INTERVENTIONS: Breast needle biopsy and mammary resection were performed. Pathological staining of the bulk resected tumor after preoperative preparation revealed that the tumor-like tissue was enriched for spindle cells arranged in fascicular clusters. Histopathological diagnosis and immunohistochemistry confirmed the mass as being a breast IMT. OUTCOMES: No metastatic recurrence was found during 6-month or 1-year follow-ups. LESSONS: Breast IMTs commonly develop in elderly women with atypical imaging features. They are primarily composed of lobular soft tissues infiltrated with an abundant focal blood supply and granular calcification. Development of breast IMTs is closely related to trauma. A preliminary diagnosis of such masses can be made based on combined manifestations of both clinical and imaging features, while a final confirmation still requires pathological staining. Imaging examinations are of value for such tumors to define the lesion edges and their associations with adjacent tissues.