Inflammatory myofibroblastic tumour of the breast: report of a case with giant vacuolated cells

Inflammatory myofibroblastic tumours (IMTs) or inflammatory pseudo-tumours are uncommon lesions of unknown aetiology. The majority of the cases are reported in the lungs of young patients. Extra-pulmonary anatomic locations include the abdomen and pelvis, but rare cases have been described in the breast. We describe an IMT in an 86-year-old female, presenting as a well-circumscribed palpable mass in the left breast. Histologically the remarkable feature was the presence of giant vacuolated cells intermixed with spindle cells and a prominent plasma cell infiltrate immersed in a fibrous hyalinized stroma. Immunohistochemical and electron microscopy studies demonstrated the myofibroblastic nature of the giant vacuolated cells and the spindle cells, and the polyclonal nature of the plasma cells. The morphologic and immunohistochemical findings supported the diagnosis of IMT. The biological behaviour of IMT in this age group is unknown and surgical excision with close mammographic follow-up is considered to be appropriate treatment for this lesion in the breast.