Myofibroblastomas are soft-tissue neoplasms that are thought to arise
from myofibroblasts. They are mostly observed in males 41–85
years of age; however, this lesion also occurs in women. The usual
clinical presentation is a unilateral painless lump that is not
adherent to overlying or underlying structures. Microscopically,
myofibroblastomas can be divided into 5 subtypes: classical,
epithelioid, collagenised, cellular, and infiltrative. Mammary ducts
and lobules are absent in the typical histological subtypes and the
adjacent breast parenchyma may form a pseudocapsule. The majority of
myofibroblastomas are immunoreactive for CD34, desmin, smooth muscle
actin, and vimentin and are negative for cytokeratin and S-100 protein.
We present a case of a giant myofibroblastoma arising in the background
of gynecomastia in an adult male
