Massive Breast Intraductal Papilloma Undiagnosed After Several Core Needle Biopsies: A Case Report

Background: Patients with breast Intraductal Papilloma (IDP) and atypical ductal hyperplasia have an increased risk for breast cancer. Core Needle Biopsy (CNB) plays a significant role in inchoate diagnosis of atypical IDP. However, the standard procedure of CNB may be unable to provide definite diagnosis of a complicated large mass. This is the first report of the largest case of peripheral atypical IDP with ductal epithelial atypical hyperplasia and hemorrhage necrosis. The mass grew larger, without a clear diagnosis. Herein, we documented our recommendations for the treatment of a large breast mass. 1.2. Case Summary: A 74-year-old Chinese female had a palpable left breast mass for two years, which was enlarging in the past one month. The patient had periodic breast check-ups in a reputed hospital. However, the ultrasound examination and four CNBs of the breast mass did not provide a clear diagnosis, besides non-lactating mastitis. However the mass was finally diagnosed as an atypical IDP after intraoperative pathology. The patient recovered well after the lumpectomy. Conclusion: When obtaining the sample from cystic tissue during CNB, the needle should take the core of the mass as well as the surrounding wall of the cyst. Clear diagnosis is important for further treatment. Large breast IDP in elderly may develop into breast cancer, so we recommend that lumpectomy is necessary rather than periodic check-ups for these patient.