Idiopathic Granulomatous Mastitis : Diagnostic Strategy and Therapeutic Implications in Omani Patients = إلتهاب الثدي الحبيبي : خطط التشخيص و التطبيقات العلاجية للمرضى العمانيين

Abstract

abstract:Objectives: Idiopathic granulomatous mastitis (IGM) is a rare benign disorder of the breast whose aetiology is controversial, and is often misdiagnosed clinically and radiologically as mammary malignancy; as a result, it may be incorrectly treated. Although no standard treatment is available for this chronic disease, surgery with or without corticosteroids has been tried with controversial results. This study discusses the clinical presentation, diagnosis, management, recurrence, and follow-up data of IGM with a review of relevant literature. Methods: From 2009-2012, the Breast Unit at Sultan Qaboos University Hospital, Oman, conducted a clinical study on 20 patients with breast lumps. Their clinical and radiological examinations were indeterminate, and a diagnosis of granulomatous mastitis was established only by histopathology. Results: The majority of the patients were cases of unknown aetiology, who presented with a unilateral breast mass. A few patients had a mass with an abscess, along with axillary lymphadenopathy. A total of 4 patients were suspected of malignancy using radiology. In all patients, sterilised pus was sent for culture and sensitivity. Microscopy showed the characteristic pattern of granulomatous inflammation. All patients were treated with antibiotics for 6 weeks, and the mean follow-up period was 15 months (11-33 months). All patients had complete remission with no further recurrence. Conclusion: This single largest study of cases of IGM in Oman highlights the pitfalls in diagnosing this non-neoplastic disease of unknown aetiology and uncertain pathogenesis. It emphasises IGM's excellent response to antibiotics, which is crucial, as IGM is a disease which is notoriously difficult and controversial to treat.

Granulomatous Mastitis: A Ten-Year Experience at a University Hospital

“…In TM, the most common features include caseous necrosis, epithelioid histiocytes, Langhans' giant cells and granulomas. The presence of predominantly neutrophils in the background, and the lack of caseous necrosis may favour a diagnosis of IGM rather than that of TM [2][3][4]27]. In all our cases, the presence of caseous necrosis, in addition to other features mentioned above in the histologic evaluation of biopsy specimens, favoured the diagnosis of TM.…”

“…Breast imaging modalities, such as mammography and ultrasound, may be useful adjuvant diagnostic tools in the overall process of diagnosing TM [13,27,29]. However, these imaging modalities are by no means reliable in distinguishing TM from that of a breast malignancy [34].…”

“…The accurate diagnosis of TM has traditionally relied upon the demonstration of a classical caseous lesion, acid-fast bacilli within such a lesion, and/or the demonstration of epithelioid granulomas, Langhans' giant cells and lymphocytic aggregates [13,27,29]. It has been more recently recognized that an AFB-positive smear is not always sufficient evidence for the definitive mycobacterial diagnosis of tuberculosis.…”

“…Medical treatment with a four drug regimen of rifampicin, isoniazid, pyrazinamide, and ethambutol forms the basis of TM treatment [13,27,29]. Surgical intervention is generally reserved for diagnostic purposes, aspiration/drainage of a residual breast mass (representing a "cold abscess"), excision of a residual mass and excision of a residual sinus tract.…”

Idiopathic granulomatous mastitis: A systematic review of 3060 patients

“…The characteristic of reviewed articles is summarized in Table (). The total number of articles was 70, 59 in group A and 11 in group B.…”