RESUMEN
Mucinous carcinoma of the breast is a type of well-differentiated adenocarcinoma, a rare subtype of infiltrating ductal carcinoma. It represents approximately 2% of all invasive breast carcinomas. The mean age of presentation is 65 years, with an incidence of 1% in women younger than 35 years. Depending on the mucin content of the carcinoma, they are described as pure or mixed; the distinction between the 2 is important for prognosis and treatment. The treatment of special types of breast cancer is still controversial due to the limited amount of evidence, however, the main treatment for breast cancer is still surgery. We present a case of a 29-year-old patient with mucinous carcinoma of the breast with a delay in its management, but with a favorable postoperative result.