Breast Pathology

The Breast Pathology Service, led by Dr. Melinda Lerwill, provides diagnostic services to Massachusetts General Hospital and outside pathologists in the U.S. and abroad, and to breast cancer researchers at the Mass General, Dana-Farber Cancer Institute, Massachusetts Institute of Technology, and National Institutes for Health. The Breast Pathology Service is fully integrated with the breast clinical services and serves a critical consultative role in the case management of breast cancer patients. The Breast Pathology team has a broad range of expertise from classical histomorphology to molecular pathology, and the research efforts of this group reflect these diverse fields. Significant initiatives are currently underway that focus on molecular pathologic technologies as they pertain to the diagnosis and clinical management of breast cancer patients.


  • Melinda Lerwill, MD - Subspecialty Head, Breast Pathology Service
  • Dennis C. Sgroi, MD
  • Amy Ly, MD
  • Veerle Bossuyt, MD
  • Anthony Guidi, MD

Clinical Program

The Breast Pathology Service sees approximately 4,500 case accessions per year. Of these, 3,400 represent in-house breast cases; approximately 50% are excisional biopsies, 25-30% are core biopsies, and 15-20% are mastectomy specimens. Approximately 1,100 outside consultation cases per year are reviewed, including patient referrals, consultation requests from area hospitals, and private consultation material. ER, PR, and HER2 IHC and HER2 FISH are performed within the Mass General Department of Pathology on all in-house breast cancer cases.

The Breast Pathology Service is split into three clinical services: Breast 1, Breast 2, and Breast 3. Residents are assigned to the Breast 1 service for their core rotations. They are responsible for 4-6 surgical specimens per day, as well as all breast core biopsies and breast skin biopsies. The Breast 2 service covers one-third of the in-house surgical cases and the outside referral cases for the Breast Center Multidisciplinary Conferences. Upper-level residents on elective and visiting fellows rotate on the Breast 2 service. The Breast 3 service covers one-third of the in-house surgical cases and the remaining outside referral cases. Individual pathologists handle private consultations that are directed to them.

Academic and Research Accomplishments

Information regarding specific research interests and links to PubMed can be found on individual faculty profiles (see below physician profiles section).

Teaching and Educational Activities

Breast Pathology Weekly Conference: All breast pathologists, the breast pathology fellow, and rotating residents review diagnostically challenging cases on a weekly basis.

Resident Teaching: During daily breast signout, each breast pathology staff member teaches the principles of gross and histological diagnosis to residents. In addition, the staff actively participate in resident teaching conferences. The Breast Pathology Service has developed a comprehensive Breast Manual, reviewing educational objectives, procedural protocols, and classic papers in breast pathology.

Breast Center Multidisciplinary Conferences: A breast pathologist and/or breast pathology fellow reviews pathology slides of patients who are seen in the clinic. This activity takes places 4 times per week throughout the entire year.

Graduate Medical Education: The Mass Generalbreast pathology groupin collaboration with Memorial Sloan Kettering Cancer Center, has offered an annual breast pathology course since 2007 entitled "Solving Everyday Problems in Breast Pathology: A Morphologic Approach." The breast pathology faculty frequently teach at a number of other continuing medical education courses, both nationally and internationally.

Breast Pathology Fellowship

This fellowship seeks to prepare a trainee in pathology for an academic career devoted to the study of breast pathology. The program provides intensive training in the pathologic diagnoses of breast diseases, a concentrated experience in translational research, participation in a multidisciplinary approach to treatment planning, and opportunities for collaborative clinical research.

The program is designed as a one-year program that consists predominantly of breast pathology service work. The breast pathology fellow will have four major activities:

  • Diagnostic - The fellow will spend 75% of their signout effort in breast pathology, with the remaining 25% in a second subspecialty area decided upon by the applicant and the program director. Supervision from a senior pathologist will be provided as needed.
  • Consultative - The fellow will serve as the pathology consultant during multidisciplinary breast cancer treatment planning sessions those weeks they are assigned to the Breast 2 service, with supervision from a senior pathologist as needed.
  • Teaching - The fellow teaches the principles of histologic diagnoses to junior pathology residents, both in the context of signout activities on the Breast 1 service and as a participant in the daily surgical pathology conference. In addition, the fellow provides informal teaching to residents, fellows, and staff members in the Departments of Radiation Oncology, Surgical Oncology, Medical Oncology and Radiology during the multidisciplinary conferences.
  • Research - During off-service time, the fellow will pursue clinical or translational research projects carried out in collaboration with members of the Breast Pathology Service and with staff and fellows in the Departments of Radiation Oncology, Surgical Oncology, and Medical Oncology.