Pathology A 65-year-old woman is found to have a 1-cm mass in the upper outer quadrant of the left breast. The most likely cause is A Fibrocystic disease. B Acute mastitis. C Fibroadenoma. D Carcinoma. 💡 Explanation A 65-year-old woman is found to have a 1-cm mass in the upper outer quadrant of the left breast. The most likely cause is ✓ Correct Answer: D. Carcinoma.