Myofibroblastoma of female breast masquerading as schirrous malignancy - a rare case report with review of literature.

Myofibroblastoma is a rare benign mesenchymal tumour of the breast commonly reported in males. It is a spindle cell neoplasm exhibiting myofibroblastic differentiation with characteristic immunohistochemical staining. Herein, we present a case of myofibroblastoma in a premenopausal female which was mimicking like malignancy clinically. Lump was growing rapidly in size measuring 8 cm x 6 cm and stony hard in consistency. Mammogram showed a large homogeneous hyperdense lump suggestive of fibroadenoma, Hamartoma and fibromatosis. FNAC and trucut biopsy of mass could not be done due to stony hard consistency. Hence excision biopsy was done. Histopathological examination revealed the tumour as myofibroblastoma. Immunohistochemical staining for markers of myofibroblasts like CD-34 and Vimentin showed strong positivity. A negative expression for cytokeratin was noted. This case is presented for its rarity, unusual clinical presentation and stony hard consistency.