Invasive papillary carcinoma of the breast: A case report.

Invasive papillary carcinoma (IPC) of the breast is a rare form of cancer. The current report documents a case of IPC characterized by a large tumor size and skin involvement. Surgical exploration revealed no evidence of axillary lymph node metastasis in breast cancer. Due to financial constraints, the patient opted solely for anastrozole endocrine therapy at a dosage of 1 mg/day for a period of 5 years post-surgery, foregoing other treatments such as radiotherapy and chemotherapy. Since discharge, 2.5 years have passed, during which the patient has been followed up via phone every 3 months, showing a good prognosis. A literature review indicated that IPC is prevalent amongst the elderly population and can be misdiagnosed due to its morphological, cytomorphological and immunophenotypic overlap with other types of papillary neoplasms. This tumor exhibits a more favorable prognosis compared with IDC, primarily attributed to its advantageous gene and molecular expression patterns, coupled with its decreased invasiveness. Despite limited evidence-based research on the treatment of IPC, the present case report, albeit with limitations, underscores the importance of avoiding over-treatment and suggests the feasibility of combining surgery with endocrine therapy for IPC.