Diagnostic and Differential Considerations in Squamous Breast Lesions
Squamous metaplasia is allegedly a very rare finding in breast tissue that has been previously reported in association with ducts, sclerosing lesions, fibrocystic changes, fibroepithelial lesions, papilloma(s), and cysts. Notably, it is not uncommon to see squamous metaplasia of lobules and ducts at the site of prior biopsy or resections. Although squamous metaplasia is clinically irrelevant, care should be taken to rule out a malignant process, which can also show squamous cells. The differential diagnosis would include low-grade adenosquamous carcinoma, metaplastic squamous cell carcinoma, cutaneous squamous cell carcinoma, and metastases.
