Solution: Classic MRI Features of Mucinous carcinoma. This a lobular tumor and is the only breast neoplasm that is T2 hyperintense due to the mucin. Mucinous carcinoma of the breast is a rare type of invasive breast cancer, diagnosed in less than 3% of all women diagnosed with breast cancer. On biopsy thready mucous like samples are obtained. Prognosis is better than most invasive breast cancers.