Epidermal inclusion cyst (EIC) arising from the breast is an uncommon benign condition. We report two cases of enlarging EIC of the breast in two women in their forties. The diagnosis of this condition may not be straightforward with imaging alone if an EIC presents as an enlarging lump in the breast and mimics a benign breast lesion, most commonly a fibroadenoma or malignant lesion with benign imaging features. Excision is usually recommended for a definite histopathological diagnosis and for the prevention of potential risks of malignant transformation. Asymptomatic stable lesions do not require treatment; biopsy is unnecessary, and follow-up imaging suffices if typical sonographic and clinical findings are found.