Rare Breast Cancer Subtypes: A Case Study Series on Mucinous, Metaplastic, Medullary, and Papillary Carcinomas (Code-T0258)

Breast cancer is a diverse disease with multiple histological subtypes, each having distinct clinical characteristics, prognostic factors, and responses to treatment. While invasive ductal carcinoma remains the predominant form, rarer subtypes, such as Mucinous Carcinoma, Metaplastic Carcinoma, Medullary Carcinoma, and Invasive Papillary Carcinoma, present unique challenges in diagnosis and management. This case study series presents four patients, aged 40 to 85, diagnosed with these uncommon breast cancer variants. The first case is a 63-year-old woman diagnosed with Mucinous Carcinoma, which is marked by mucin production and typically shows lower rates of lymph node involvement. Surgical excision was performed with clear margins, and no lymphatic spread was detected, indicating a favorable prognosis. The second case involves a 75-year-old woman diagnosed with Metaplastic Carcinoma, specifically low-grade Adenosquamous Carcinoma. Despite its relatively low grade, there was evidence of lymph node involvement, a factor often linked to a poorer prognosis. The third case presents a 45-year-old woman with Medullary Carcinoma, a high-grade tumor that frequently occurs in younger patients. Although the tumor displayed aggressive features, lymph node involvement was absent, suggesting a better prognosis. The fourth case is a 68-year-old woman diagnosed with Invasive Papillary Carcinoma, which exhibited moderate differentiation with well-defined papillary structures. This patient also had clear margins and no lymph node involvement, aligning with the generally favorable outcomes for this subtype. This case series highlights the necessity for personalized treatment regimens, as rare breast cancer subtypes may not follow conventional therapeutic guidelines. Accurate histopathological evaluation, alongside immunohistochemical analysis and imaging, is crucial in guiding treatment decisions and improving patient outcomes. This study enriches the existing literature on rare breast cancer subtypes and emphasizes the need for early detection and tailored therapeutic strategies.

Keywords: Rare breast cancer subtypes, Mucinous carcinoma, Metaplastic carcinoma, Medullary carcinoma, Invasive papillary carcinoma, Histopathology.