[A Case of Rapidly Growing Breast Spindle Cell Carcinoma].

We report a case of rapidly growing breast spindle cell carcinoma. The case was a 69-year-old female. Her chief complaint was right breast pain. She was being followed after surgery for left breast cancer but was seen because of right breast pain. In the right mammary gland CD area, a 27×27 mm large unclear mass lesion was observed, which had not been seen half a year prior. Right mastectomy and axillary dissection were performed following a preoperative diagnosis of pT2N1M0, pStage ⅡB ductal carcinoma. Currently, 2 years and 2 months have passed since the operation, and recurrence has not been observed. Case reports of rapidly growing breast spindle cell carcinoma are occasionally found, but no literature specifically defines acute growth. Here, we defined rapid growth using the tumor doubling time(DT)proposed by Gerstenberg et al. Of all the reported cases of breast spindle cell carcinoma, the DT was fewer than 90 days in most cases. Breast spindle cell carcinoma demonstrates rapid grown compared to normal breast cancer.