Primary squamous cell carcinoma of breast (a case report).

Primary squamous cell carcinoma of breast is an unusual malignant neoplasm and has much lower incidence compared to other breast cancers. We report a case of primary squamous cell carcinoma in a 61 years old woman who presented with a palpable mass in the left breast of 2 months duration. FNAC smears revealed malignant squamous cells. Histopathological examination showed features of squamous cell carcinoma (large cell keratinizing) the tumor being composed entirely of neoplastic squamous cells. Skin or dermal adnexae of the breast and nipple were not involved by the tumor. There was no component of obvious invasive ductal carcinoma or other features of metaplastic carcinoma. All the axillary nodes dissected were free from tumor deposit. The tumor was negative for estrogen receptor (ER), progesterone receptor (PR) and Her2/neu oncoprotein expression. Through clinical examination and extensive investigations ruled out any other primary focus of tumor outside the breast. The patient received chemotherapy with 5Flurouracil and Cisplatin following modified radical mastectomy and is asymptomatic in the 18 months follow up period. So, in a breast tumor showing malignant squamous cells on FNAC or histopathological examination, possibility of primary squamous cell carcinoma should be considered in the differential diagnosis. Diagnosis requires detailed clinical history, through examination and extensive investigations to exclude any extramamary primary along with careful histopathologic examination. This case is being reported for its extreme rarity.