SummaryA 46‐year‐old woman had a well differentiated squamous cell carcinoma of the hreast excised. This tumour was not attached to skin, there was no associated adenocarcinorna, and it had metastasized to axillary nodes as squamous cell carcinoma.She remains well seven and one‐half years following operation.This is thought to be an authentic example of a rare neoplasm. Despite the rarity of the cmndition its existence should be remembered in the differential diagnosis of a lump in the b