Case Report
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Dec 16, 2016; 4(12): 409-412
Published online Dec 16, 2016. doi: 10.12998/wjcc.v4.i12.409
Granulomatous lobular mastitis secondary to Mycobacterium fortuitum
Armin Kamyab
Armin Kamyab, Department of Surgery, Cox Monett Hospital, Monett, MO 65708, United States
Author contributions: Kamyab A solely contributed to this paper.
Institutional review board statement: This case report was exempt from the Institutional Review Board standards as it is a case report.
Informed consent statement: The patient involved in this study gave her written informed consent authorizing use and disclosure of her protected health information.
Conflict-of-interest statement: The author has no conflicts of interest to disclose.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Armin Kamyab, MD, Chief of Surgery, Department of Surgery, Cox Monett Hospital, 801 N Lincoln, Monett, MO 65708, United States.
Telephone: +1-417-2362440 Fax: +1-417-3541458
Received: February 22, 2016
Peer-review started: February 24, 2016
First decision: April 26, 2016
Revised: April 29, 2016
Accepted: June 1, 2016
Article in press: June 3, 2016
Published online: December 16, 2016

Granulomatous lobular mastitis is a rare inflammatory disease of the breast of unknown etiology. Most present as breast masses in women of child-bearing age. A 29-year-old female presented with a swollen, firm and tender right breast, initially misdiagnosed as mastitis. Core needle biopsy revealed findings consistent with granulomatous lobular mastitis, and cultures were all negative for an infectious etiology. She was started on steroid therapy to which she initially responded well. A few weeks later she deteriorated and was found to have multiple breast abscesses. She underwent operative drainage and cultures grew Mycobacterium fortuitum. Granulomatous lobular mastitis is a rare inflammatory disease of the breast. The definitive diagnose entails a biopsy. Other causes of chronic or granulomatous mastitis should be ruled out, including atypical or rare bacteria such as Mycobacterium fortuitum. This is the first reported case of granulomatous mastitis secondary to Mycobacterium fortuitum. With pathologic confirmation of granulomatous mastitis, an infectious etiology must be ruled out. Atypical bacteria such as Mycobacterium fortuitum may not readily grow on cultures, as with our case. Medical management is appropriate, with surgical excision reserved for refractory cases or for drainage of abscesses.

Keywords: Breast, Granulomatous, Lobular, Mastitis, Breast mass, Mycobacterium fortuitum

Core tip: Granulomatous mastitis is a rare inflammatory disease of the breast, that often presents as a breast mass. The exact etiology is unkown. We report a rare presentation of this conditions arising in the right breast of a 29-year-old female. The treatment if granulomatous mastitis is yet to be defined, but literature supports non operative management with steroids, with surgery reserved for failure of medical management. Failure of steroid therapy should raise the suspicion of an underlying misdiagnosed infectious etiology. If an infectious etiology is identified however, medical management with antibiotics remains the mainstay for treatment.