Pathology: myofibroblastoma
Myofibroblastoma, mammary-type
Circumscribed and unencapsulated; fascicles of spindle-stellate cells
Eosinophilic cytoplasm
Monomorphic ovoid nucleoli; inconspicuous mitotic activity
Intervening stroma is collagenous-myxoid
IHC: desmin, CD34, RB1
Myofibroblastoma, mammary-type
Circumscribed and unencapsulated; short spindle cell fascicles
Eosinophilic cytoplasm
Monomorphic ovoid nucleoli with small nucleoli; inconspicuous mitotic activity
Intervening stroma is collagenous
IHC: CD34
Myofibroblastoma, mammary-type
Circumscribed; short spindle cell fascicles
Eosinophilic cytoplasm
Monomorphic ovoid nucleoli with small nucleoli; inconspicuous mitotic activity
Intervening stroma is myxoid with collagen bands; prominent adipocytic component
IHC: CD34, desmin, RB1
Myofibroblastoma, mammary-type
Short spindle cell fascicles
Eosinophilic cytoplasm
Monomorphic ovoid nucleoli with small nucleoli; inconspicuous mitotic activity
Intervening stroma is myxoid with broad collagen bands; interspersed adipocytes
IHC: CD34, desmin