Squamous cell carcinoma of the breast after augmentation with liquid silicone injection.

Squamous cell carcinoma of the breast is an extremely rare neoplasm. Approximately 50 cases have been reported in the English literature since 1917. The pathogenesis of squamous cell carcinoma of the breast is puzzling because epithelial elements are not normally identified in breast tissue. It has been suggested that epithelial cells are derived from epidermoid cysts deposited during early embryological development, from metaplastic transformation of ductal cells, or after trauma or surgical manipulation. Although no evidence has been published to support a casual relationship between liquid silicone-induced mastopathy and breast carcinoma, squamous cell cancers are known to arise in the setting of prolonged inflammation often seen after liquid silicone injection. This case of primary squamous cell carcinoma of the breast, arising 25 years after augmentation with liquid silicone injections, occurred in a 70-year-old patient with silicone-induced mastopathy.