[A Case of Late Recurrence of Breast Cancer Causing Carcinomatous Pleurisy 29 Years Postoperatively].

The patient was a 81-year-old female with a history of treatment for the right breast cancer 29 years earlier. She presented with a chief complaint of dyspnea. CT showed pleural effusion and a mediastinal tumor. A biopsy was performed on the mediastinal tumor, and not only pathological but also immunohistological examination findings were similar to those of the surgical specimens 29 years ago. In view of the patient's age, we initiated treatment by anastrozole. The treatment was effective, and other forms of endocrine therapy were administered. She continued to be treated with the endocrine therapy over 4.5 years. The late recurrence of breast cancer in the form of carcinomatous pleurisy 29 years postoperatively is rare.