Breast cancer and large-cell neuroendocrine carcinoma harboring the same PIK3CA mutation: A case report
The distinction between a metastatic recurrence and the onset of a second primary malignancy can be diagnostically challenging. Precision medicine can offer valuable support in this context.
A 34-year-old woman was diagnosed in 2012 with hormone-receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer in the left breast, with homolateral axillary node involvement but no distant metastases.

