Myofibroblastoma of the Breast: A Rare Cause of Breast Lump in a Postmenopausal Woman

Abstract

A breast mass in a postmenopausal age woman is treated with a high index of clinical suspicion for malignancy. Myofibroblastoma (MFB) of the breast is a very rare benign stromal tumor, predominantly occurring in menopausal women and older men. Owing to its rarity, nonspecific radiology, cytomorphology, and many variants, it can be confused with other malignant and benign breast lesions and hence can be a source of diagnostic pitfall. We present a case of an MFB of the breast in a 55-year-old female, which was detected on a routine screening mammography. Fine-needle aspiration cytology was inconclusive. Final diagnosis was made by histopathology and immunohistochemistry examination. We report this case as the likelihood of encountering MFB has increased in recent years due to routine mammographic screening, and this lesion should be kept in the differential diagnosis of spindle-cell lesions of the breast.

Mammary Myofibroblastoma in a Male: A Case Report and Review of the Literature

“…Myofibroblastoma is a rare, benign, stromal tumor of the mesenchyma with myofibroblastic differentiation [ 2 , 3 ]. It has been reported in mammary and extramammary regions [ 2 ], including the head, neck, soft tissue, skin, lymph node, axilla, parotid gland, and groin [ 4 - 7 ], with similar histology and immune‑phenotyping [ 1 ]. MFB was first described in 1987 by Wagortz et al, who reported 16 cases (11 in men) [ 8 ].…”

“…A review of the literature revealed 43 cases of MFB (25 men, 17 women, and one transgender patient aged 35-96 years). Among them, 24 were incidental findings on routine mammography screening [ 2 ] or other screenings for unrelated symptoms [ 1 , 12 ], and 19 involved a palpable mass or other symptoms [ 3 ]. Differential diagnoses for breast mass in males include gynecomastia, infection, lipoma, granular cell tumor, metastatic disease, and schwannoma [ 13 ].…”

“…Myofibroblastoma is a benign stromal tumor that has been identified in mammary and extramammary regions [ 1 ]. Mammary myofibroblastoma (MFB) is rare, with similar rates of occurrence among males and females and greater incidences in older versus younger men and postmenopausal versus premenopausal women [ 2 , 3 ]. These tumors can be symptomatic or asymptomatic and are often discovered incidentally [ 1 ].…”

“…These tumors can be symptomatic or asymptomatic and are often discovered incidentally [ 1 ]. To date, fewer than 90 cases of MFB have been reported [ 2 ]. We present a case of a 76-year-old male who presented with a palpable breast mass.…”

Myofibroblastoma of the Breast: A Morphologic and Immunohistochemical Study of Three Cases

“…MFB has been suggested to arise from mammary stromal fibroblasts with positivity for CD34 and vimentin markers. On the other hand, expression of ER, PR and AR receptors in these cells guided us to a probable role of sex steroid hormones in their pathogenesis (5). Myofibroblast cells are capable of multidirectional mesenchymal differentiation, which can further differentiate into smooth muscle, cartilage, or osseous tissue (1).…”