2020 年 59 巻 13 号 p. 1665-1669
A 40-year-old woman presented with a left adrenal incidentaloma. Based on the presence of café-au-lait spots, cutaneous neurofibroma, and family history, she was diagnosed with neurofibromatosis type 1 (NF1). Adrenal incidentaloma screening showed an elevated normetanephrine level; the left adrenal mass showed the uptake of I-123 meta-iodobenzylguanidine. She underwent left adrenalectomy, and pheochromocytoma was diagnosed. One year later, the results of a biopsy of a palpable mass in the left breast suggested invasive ductal carcinoma. The patient underwent neoadjuvant chemotherapy followed by left breast-conserving surgery. We herein report a rare case of an NF1 patient who developed both pheochromocytoma and breast cancer.