Abstract
Nodular fasciitis (NF) is a benign soft tissue lesion that can occur anywhere in the body. Its occurrence in the breast is a rare phenomenon, but is clinically important to distinguish from a malignant tumor as they both present as lesions of the breast. In this report, we discuss a case of NF of the breast in an postmenopausal woman who presented with an asymmetry of the breast on an annual screening mammogram followed by diagnostic imaging and a core biopsy. Ultimately, excision of the lesion (1.2 cm) was the definitive treatment for this patient and histological evaluation confirmed the diagnosis of NF. Additionally, we review the most recent literature on this topic discussing the significance to better understand the characteristics and best treatment course for breast NF. Results from a review of 11 breast NF cases demonstrated that the average age at diagnosis is 49, the mean diameter of lesions was 1.33 cm, and lesions were more frequently identified in the right upper breast. The clinical features of breast NF may present similarly to that of a malignant tumor. Accurate diagnosis with immunohistochemistry staining or USP6 FISH analysis is critical to prevent misdiagnosis and overtreatment. Clinician awareness, surgical treatment, and patient education are important for best management of breast NF.