A large epidermoid cyst of breast mimicking carcinoma: A case report and review of literature

Abstract

Introduction: Triple assessment of a suspicious breast lesion may not always provide a definite diagnosis. We report a case of epidermoid cyst of breast, which caused diagnostic dilemma in spite of a thorough triple assessment and entailed mastectomy.

Presentation of case: A 69-year-old woman presented with a large painful retroareolar left breast mass. Clinical examination, ultrasound and mammography were highly suspicious of malignancy. However, core biopsy suggested a benign lesion. Due to size of the lesion and diagnostic uncertainty, various options were discussed with the patient. She opted for a simple mastectomy. The histology confirmed a large epidermoid cyst.

Discussion: It is rare for an epidermoid cyst to present as such an advanced lesion, mimicking carcinoma. Excision of such a large retroareolar 'benign' lesion, however, may sometime entail mastectomy. This is the first reported case of an epidermoid cyst of breast necessitating mastectomy.

Conclusion: Diagnostic dilemma while dealing with a suspected breast cancer is not rare. Involvement of multidisciplinary team as well as patient is important in the decision-making. The report illustrates a rare presentation of a deep seated large epidermoid cyst of breast, which mimicked carcinoma, caused diagnostic confusion and entailed mastectomy. We strongly advocate the option of breast reconstruction in such cases.

Fig. 1

Mammogram of the left breast (medio-lateral oblique view) showing a central mass with some lack of clarity of the margin and ductal prominence anteriorly (M4).

Fig. 2

Ultrasound scan of the left breast showing a solid mass with extension into the duct system (U4).

Fig. 3

Core biopsies of the lesion of the left breast (H & E; 40×) showing periductal mastitis, duct ectasia, fragments of acanthotic squamous epithelium with no evidence of malignancy.

Fig. 4

Macrophotographs of the left mastectomy specimen (suture marking superior border) showing the lesion near the centre of the breast.

Fig. 5

Microphotograph of the histology (H & E; 40×) of the left breast lesion showing cyst, lined by squamous keratinised epithelium, suggestive of an epidermoid cyst.