A case of a 54-year-old woman who presented with a breast mass is reported.
Histologically, a chronic granulomatous inflammatory response was observed
. The response was associated with an organism diagnosed as a fly larva, De
rmatobia hominis (human botfly). The incidence of myiasis, infestation by f
ly larvae, presenting as a long-standing breast mass and mimicking a neopla
sm is extremely rare, especially in the United States.