Mucinous Carcinoma of the Breast: A Case Series of Five Patients

Abstract Background: Mucinous carcinoma (colloid carcinoma) of the breast is a rare subtype of invasive ductal carcinoma, comprising about 1–4% of all breast cancers. It is characterized by abundant extracellular mucin production and usually has a favorable prognosis compared to other invasive breast carcinomas.Objective: To describe the clinical, pathological, and prognostic characteristics of five patients diagnosed with mucinous carcinoma of the breast.Methods: A retrospective study of five histologically proven cases was conducted with analysis of clinical, imaging, histopathological, and follow‑up data.Results: Patients ranged from 45–72 years. Three cases were pure mucinous carcinoma and two were mixed type. All tumors were ER/PR positive and HER2 negative. Pure variants showed no nodal metastasis.Conclusion: Mucinous carcinoma generally carries an excellent prognosis, especially in pure variants. Accurate histological distinction is essential for treatment planning.