Pure Mucinous Breast Carcinoma with Micropapillary Pattern in a ۳۲-Year-Old Female

Background:Mucinous carcinoma (MC) is a rare breast malignancy with a large extracellular mucin secretion. It has a good prognosis in comparison to other breast malignancies.Case presentation:We report a ۳۲ years old female with multiple hard palpable masses in the left breast with rapid growth in ۶ months. She was mentally retarded with lower limb varicose veins associated with mucocutaneous lesions on the face. She underwent ultrasound examination of the breast, thyroid and lower extremity veins. Core needle biopsy and fine needle aspiration from left breast lesions and right thyroid nodules showed MC and follicular lesion with hurtle cell change, respectively. Suspected metastasis in the left rib and calvarium in the subsequent bone scan survey and brain magnetic resonance imaging was reported. She underwent radical mastectomy and right hemi-thyroidectomy.Conclusion: Pure mucinous carcinoma with micropapillary pattern (MUMPC) is a new histology variant of Pure Mucinous Carcinoma (PMC) that shows favorable prognosis with less aggression and occurs in older patients. However, PMC in our patient occurred at a young age with greater aggression.