Breast Metastases From ACTH Secreting Thymic Carcinoid

A 33-year-old woman with Cushing syndrome (CS), who underwent incomplete resection of ACTH-secreting thymic carcinoid, presented with a recurrence of Cushingoid features after 3 months of surgery. CECT and PET/CT scans (18F-FDG and 68Ga-DOTATATE) revealed anterior mediastinal lesion encasing the aorta, mediastinal adenopathy, lung nodules, and left breast lesions, the latter being pathologically proven to be metastases from the neuroendocrine tumor (NET). Breast metastases from NET are rare, with their diagnosis being challenging due to considerable overlap with invasive breast cancer. Nevertheless, metastatic lesions to the breast in patients of NET should be ruled out before considering aggressive surgical management.