Homo sapiens Raw sequence reads
Mucinous cystadenocarcinoma (MCA) of the breast is a rare invasive carcinoma that resembles pancreatobiliary or ovarian mucinous cystadenocarcinoma in terms of histological appearance. Most mucinous cystadenocarcinomas of the breast are negative for ER, PR, and ERBB2 (HER2).To our knowledge, only five reports of HER2-positive MCAs have been retrieved from the English literature, and no reports focusing on the molecular characteristics of HER2-positive MCAs have been published. Here, we presentthe rare case of a 64-year-old woman with a HER2-positive MCA who underwent long-term follow-up without recurrence or distant metastasis. In addition, we provide a detailed analysis of its genomic characteristics.