en Surgery Surgery case report case report <b><font face="TimesNewRomanPS-BoldMT"><p align="left">Abstract</p></font><font size="2" face="TimesNewRomanPSMT"><font size="2" face="TimesNewRomanPSMT"><p align="left">Epidermal inclusion cysts are uncommon in the breast, but the consequences can be</p><p align="left">severe when these cysts occur in the breast parenchyma. Here, we report two such</p><p align="left">cases. The patient in case 1 was an 37-year-old woman with a 3-cm palpable mass in</p><p align="left">the right breast. Mammography revealed a round and smoothly outlined mass, which</p><p align="left">indicated a benign tumor, and sonography showed an irregularly shaped and heterogeneous</p><p align="left">hypoechoic mass, fibroadenoma was suspected on the basis of clinical and</p><p align="left">image findings, but excisional biopsy revealed an epidermal inclusion cyst. The patient</p><p align="left">in case 2 was a 50-year-old woman with a 2.5-cm lesion in the left breast. Mammography</p><p align="left">revealed a round, dense, smoothly outlined mass, and sonography showed</p><p align="left">a well-defined, central hyperechoic mass. . Breast cancer was suspected on the basis</p><p align="left">of the sonographic findings and the age of the patient, but the resected specimen revealed</p><p align="left">an epidermal inclusion cyst. Although epidermal inclusion cysts are benign,</p><p align="left">occasionally they may play a role in the origin of squamous carcinoma of the breast. .</p><p align="left">Mammographic and sonographic features of an epidermal cyst may mimic a malignant</p><p align="left">lesion. Malignant change appears to occur more frequently in epidermal inclusion</p><p align="left">cysts in the mammary gland, compared to common epidermal inclusion cysts,</p><p align="left">and this may be associated with origination of mammary epidermal inclusion cysts</p><p align="left">from squamous metaplasia of the mammary duct epithelium.</p><p align="left">Epidermmoid inclusion cyst of the breast is potentially serious, although such cysts</p><p align="left">are rare, and differentiation from a malignant or benign breast tumor is required. Excision</p><p align="left">is probably the most appropriate treatment, and can eliminate the possible risk</p><p align="left">of malignant transformation.</p></font></font></b> epidermal inclusion cyst, epidermoid cyst, breast, cancer. 207 211 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-18&slc_lang=en&sid=1 Amir R. Motabar amotabar@yahoo.com 20031947532846001693 20031947532846001693 Yes Department of Surgery, Iran University of Medical Sciences, Rasool-e- Akram Hospital