RESUMO
Also known as inflammatory pseudotumor, inflammatory myofibroblastic tumor is now considered a true low-grade neoplasm. Although the lung is the most common site, it has been described in many other locations, including the breast; the first report of breast involvement was by Pettinato et al. in 1988. We report the case of a 52-year-old perimenopausal woman presenting with a slow-growing mass in her right breast. Mammography revealed a well demarcated lesion which was hypoechoic on ultrasound. A needle biopsy was performed yielding an initial diagnosis of myofibroma and the mass was resected. Histopathology of the 5-cm tumor revealed a fusocellular proliferation with a striking presence of inflammatory cells, morphologically and immunohistochemically concordant with inflammatory myofibroblastic tumor. The patient underwent further surgery to ensure free margins and after a negative extension study (PET-CT) is receiving no further therapy. To date, she has shown no signs of recurrence 8 months postoperatively. Inflammatory myofibroblastic tumor of the breast is very infrequent, with less than 30 reported cases. Differential diagnosis with both benign and malignant entities is extensive and it may precede or coexist with carcinoma of the adjacent breast. Although it is considered a low-malignant potential lesion, there are well documented cases of recurrence and even metastasis. Surgical resection with wide margins is the primary treatment and no systemic therapy is indicated; however, clinical follow-up is mandatory as there are no well-established criteria as yet to predict the biological behavior of this tumor.