Images in Pathology - Squamous Cell Carcinoma of breast

A 47-year-old postmenopausal woman presented with the history of a lump in the upper outer quadrant of left peast for which a lumpectomy had been done. She did not have pain, nipple discharge or skin changes prior to the lumpectomy. She did not have a family history of peast cancer. The histopathology of the lump was an invasive squamous carcinoma of the peast. Examination of her oral cavity and pelvic examination was normal. Her chest radiograph was normal. She did not have any other site of squamous carcinoma. She was subsequently subjected to a mastectomy with axillary clearance. Histopathological examination after exhaustive sampling revealed a moderately differentiated keratinising type of pure squamous carcinoma (Figure 1). There was no associated in-situ carcinoma and there were no features of glandular differentiation. The axillary lymph nodes did not harbour metastases. The surrounding peast tissue had areas of inflammatory mastitis and ductal hyperplasia. There was no squamous metaplasia at the interface between the tumour and the normal peast parenchyma. The skin and the nipple-areola complex were not involved.