E1547. Breast Lymphoplasmacytic Infiltrates on Core Needle Biopsy: Now What?
  1. Joshua Weinstein; Boston Medical Center, Department of Radiology
  2. Jamie Yoon; Boston University School of Medicine
  3. Lina Ma; Boston Medical Center, Department of Pathology
  4. Michael Fishman; Boston Medical Center, Department of Radiology
  5. Jordana Phillips; Boston Medical Center, Department of Radiology
  6. Anna Rives; Boston Medical Center, Department of Radiology
  7. Priscilla Slanetz; Boston Medical Center, Department of Radiology
Lymphoplasmacytic infiltrates are a histologic finding characterized by a dense array of small lymphocytes and plasma cells in tissue. In the breast, lymphoplasmacytic infiltrates can be seen in a variety of conditions, ranging from breast malignancies including lymphoma to many non-neoplastic inflammatory entities. As a non-specific finding on breast core biopsy, this can cause a diagnostic challenge for the breast radiologist. In this exhibit, we will discuss the breast diseases that characteristically exhibit lymphoplasmacytic infiltrates on histopathology. Using a case-based approach, we will discuss the imaging findings, histopathologic features, and management of a broad array of these diseases including diabetic mastopathy, fat necrosis, IgG4 mastopathy, and MALT-lymphoma. By reviewing these entities, radiologists will gain insight into how to manage this pathology when encountered on percutaneous core biopsy.

Educational Goals / Teaching Points
The educational goals of this exhibit are: to define characteristics of lymphoplasmacytic infiltration including its prevalence, pathophysiology, and histopathology; to provide a multimodality case-based presentation and discussion of diseases that present with this histopathology; and to discuss radiologic-pathologic concordance and further management of this less commonly encountered histopathology.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
A similar histologic appearance can be seen with a variety of breast diseases that cause lymphoplasmacytic infiltration, ranging from inflammatory conditions such as diabetic mastopathy and IgG4 mastopathy to malignancies, typically breast lymphomas. While there are many tools the pathologist can use to help differentiate these conditions, it is important for the breast radiologist to be aware of the diagnostic challenge, as it is the breast radiologist’s responsibility to determine the concordance of the clinical, radiologic, and pathologic findings to confirm the diagnosis and determine the next steps in management.

By discussing the broad differential diagnosis of lymphoplasmacytic infiltrates on core needle biopsy and reviewing case-based examples showing the radiologic and pathologic findings, radiologists can be better prepared for how to manage this pathology when encountered in clinical practice.