Context: Displacement of epithelial cells (DE) in the breast may occur after various types of needling procedures.
Objective: To determine if specific lesions or entities in the breast are more prone to displacement than others.
Design: A review of our computer files from January 1994 to June 2004 yielded 53 cases with DE. Clinical information, including the age of the patient, specific reason for the biopsy, and type of biopsy, was gathered. Histologic review of all hematoxylin-eosin-stained slides (core biopsies and excisions) was performed.
Results: Needling procedures included 1 or more of the following: ultrasound-guided core biopsy (24 cases), mammotome core biopsies (16), fine-needle aspiration (8), anesthetic injection (3), suture placement (5), and wire localization (1). Procedures were performed in order to investigate a mass (34 cases), calcifications (15), both (3), or nipple discharge (1). The time from needling to surgical procedure yielding a specimen with DE ranged from minutes to 47 days. Displacement of epithelial cells occurred in the following sites: biopsy tract (42 cases), lymphatic channels (5), both biopsy tract and lymphatic channels (4), and breast stroma (2). The diagnoses included intraductal papilloma (6 cases) and intraductal carcinoma (DCIS) (45; 15 with invasive carcinoma). The remaining 2 cases were invasive carcinoma (colloid and papillary types) devoid of DCIS. Of the DCIS cases, either pure or with invasive carcinoma, the pattern was micropapillary in 23, intraductal papilloma involved by DCIS in 32, and both features in 12. The remaining 2 cases of DCIS included comedo DCIS and cribriform DCIS involving a cyst.
Conclusions: With the exception of 3 cases, DE was associated with 1 or more underlying papillary lesions, including pure intraductal papilloma, DCIS involving intraductal papilloma, micropapillary DCIS, and invasive carcinoma. Other etiologies included mucinous carcinoma and cystic lesions, with only 1 case in which a mechanism for DE could not be postulated.