ABSTRACT
Proliferating tricholemmal tumour is derived from the outer sheath of a hair follicle and usually proliferates following trauma or inflammation. It mostly has a benign character; however, sometimes it shows malignant behaviour. It is commonly seen in elderly woman and is generally located on the scalp but also can also be located on the nose, abdomen, hips, elbows and vulva. We present a case who was admitted with an enlarging mass lesion on the right breast for one year and diagnosed tricholemmal tumour pathologically. The choice of treatment was wide local excision and the patient has been healthy for a 5-year follow-up period. Two cases have been reported in the literature about breast located proliferating tricholemmal tumour, and it is remarkable for unusual location.