Early-stage triple-negative breast cancer with separate lung carcinoid and later CML

What happened, in summary

This 59-year-old nonsmoking woman noticed a firm lump near the nipple of her left breast that had been present for about 1 month. She had hypothyroidism treated with daily levothyroxine, no rapid growth of the mass, no breast pain, no nipple discharge, no recent weight loss, and no family history of similar disease. Mammography and targeted ultrasound showed a small irregular left breast mass near the nipple, measuring 12 × 8 mm on mammogram and 7 × 4.5 mm on ultrasound. Core needle biopsy showed invasive ductal carcinoma, no special type, moderately differentiated. Tumor staining was CK-positive, patchy TTF-1-positive, GATA-3-negative, ER-negative, PR-negative, and HER2-negative, with low Ki-67 expression of 1%. Axillary nodes were unremarkable on imaging. She underwent breast-conserving surgery with axillary lymph node dissection. Final pathology confirmed ductal carcinoma with clear margins, and all 9 lymph nodes were negative for malignancy. She was discharged in good condition and then received adjuvant therapy, including 30 sessions of hormone therapy and later daily letrozole with calcium and weekly alendronate. Her staging workup also found a separate left lung mass, which was diagnosed as a well-differentiated neuroendocrine tumor rather than metastatic breast cancer. That lung tumor was later removed by wedge resection. During breast cancer follow-up, 2 CT scans showed no lymph node involvement or metastatic spread, and mammography was normal. During later follow-up, an elevated white blood cell count led to a diagnosis of chronic myelogenous leukemia, treated with imatinib. As of May 2025, serial breast ultrasound examinations showed no breast or axillary recurrence.