Mammary and extramammary myofibroblastoma: multimodality imaging features with clinicopathologic correlation, management and outcomes in a series of 23 patients

Abstract

Objective: The purpose of this study was to describe the imaging appearance, diagnosis, and management of mammary and extramammary myofibroblastoma (MFB) in a series of 23 patients. Methods and materials: Following institutional review board approval, cases were identified by searching for “myofibroblastoma” in radiology reports. Multimodality imaging and pathological features were assessed. Results: 23 cases of myofibroblastoma were identified in 15 males and 8 females. Most cases were in the breast (20/23, 87%), presenting as a palpable mass or discovered incidentally on mammography in females or chest CT in males. Extramammary MFB lesions (3/23, 13%) presented with symptoms related to mass effect. At imaging, MFB most often demonstrated an oval or irregular mass that was hypoechoic or heterogeneously echogenic with variable margins. MRI showed T2 hyperintensity, diffusion restriction, and plateau kinetics. Extramammary MFB appeared as an enhancing mass with variable fat content and T2 intensity. Conclusion: Here we describe imaging and clinicopathological features of mammary and extramammary myofibroblastoma. Advances in knowledge: Imaging description of this rare tumor is limited in the literature, and to date this is the largest case series describing the imaging findings.