Abstract

Mammary myofibroblastoma, abbreviated MMFB, (aka "Wargotz tumor") is a rare, benign tumor of the breast.

Symptoms

These tumors are painless masses that manifest as breast lumps and may be found on a mammogram.

Diagnosis

The diagnosis is based on examination under a microscope, by a pathologist. Radiologic findings may be suggestive, as these tumors are well-circumscribed and devoid of calcifications.

Pathology

Myofibroblastoma of the breast, first described by Wargotz et al. {Am J Surg Pathol. 1987 Jul;11(7):493-502} consist of bland spindle cells arranged in fascicles with interspersed thick bundles of collagen. They typically stain with CD34 and desmin.

In extra-mammary sites the tumour is known as a "mammary-type myofibroblastoma", and may immunohistochemically and histomorphologically overlap with spindle cell lipoma.