Gray Zone Papillary Breast Lesions as a Diagnostic Dilemma: An Institutional Experience

Abstract

Introduction: Papillary lesions of breast presents as both diagnostic and therapeutic challenge in clinical practice. Papillary lesions arise within the ducto-lobular system and are classified into benign, borderline and malignant. Benign and malignant papillary lesions comprise less than 10% and 1% of all breast lesions cases respectively. Many papillary lesions share overlapping morphologic features and pose diagnostic dilemma. The rarity of the lesions and limited data available in the literature has prompted us to take up this study. Aim: To categorise gray zone papillary lesions of the breast with the help of immunohistochemical markers. Materials and Methods: Nineteen papillary lesions of breast were reviewed in the Department of Pathology in a tertiary health care hospital, Bengaluru, Karnataka, India from January 2016 to June 2019. Immunohistochemistry with the help of available myoepithelial markers was done in all challenging cases. Results were analysed by consensus opinion by two senior pathologists. Results: Pathological diagnosis for 19 cases of papillary lesions included 12 Intraductal papilloma, three cases of Atypical papilloma, two cases of Encapsulated papillary carcinoma and one case each of Papillary Ductal Carcinoma In Situ (DCIS) and Invasive Papillary Carcinoma (IPC). Immunoprofile for both luminal and myoepithelial cells was employed in difficult cases. Conclusion: A thorough knowledge of the clinical presentation with sonomammographic findings, histopathology and judicious use of immunoprofile will help the pathologist and clinician for the optimal management of these gray zone papillary breast lesions.

Keywords

• atypical papilloma
• encapsulated papillary carcinoma
• intraductal papilloma
• invasive papillary carcinoma