A Case of Incidental Giant Intraductal Papilloma Containing Ductal Carcinoma In Situ.

BACKGROUND: Intraductal papillomas of the breast (IDPs) are typically small benign lesions characterized by pathologic discharge, a palpable mass, or an occult presentation. Giant IDPs (> 5 cm) are a rare entity. The few existing cases of giant IDPs describe grossly apparent exam findings and concerning features on imaging. While surgical excision is the standard of care for most IDPs, there is a scarcity of evidence to guide management of giant papillary tumors.

CASE: We describe a case of a 64-year-old female presenting with pathologic nipple discharge and no discrete palpable breast mass who was routinely diagnosed with ductal carcinoma in situ (DCIS). Imaging findings of mass calcifications and intraductal mass debris correlated with biopsy results, and the patient underwent central lumpectomy with oncoplastic reconstruction. At the time of surgery, the DCIS was incidentally found to be contained within a large solitary papilloma. The specimen pathology showed DCIS spanning a large area in a multifocal pattern that involved a 7 cm giant intraductal papilloma. Though margins were negative for malignancy, the benign papillary lesion was incompletely excised. A multidisciplinary review opted to pursue whole breast radiation therapy followed by adjuvant endocrine treatment over re-excision.

CONCLUSION: This unusual case highlights the potential for giant IDP to remain clinically occult in the background of known ductal carcinoma in situ and emphasizes the value of multidisciplinary care discussion and a patient-centered approach to surgical decision making in the absence of existing guidelines.