This IGM case demonstrates potential difficulties in diagnosis and management, iatrogenic complications, the need to involve different areas of expertise, and the absence of knowledge about the etiology of IGM.
IGM is a relatively recent reported condition which was first described in 1972 by Kessler and Wollock. It has also been called granular lobular mastitis by Going et al since 1987, based on histological samples that had a lobule-centered distribution from patients with the disease. It is a rare, benign, inflammatory chronic condition of unclear etiology. The primary presentation is a firm breast mass, which is tender. It has been reported that up to 25% of cases can involve both breasts. The full presentation includes breast masses, tumorous indurations, skin ulcerations, inflammation, local pain, tenderness, galactorrhea, abscesses and fistulae. Some authors have suggested that IGM is a self-limiting condition, with a range of two to 24 months but a chronic presentation could last for several years.
IGM is seen more frequently in premenopausal women, but the age of presentation can widely vary. It has been reported in an 11 year old girl as well as cases in the 6th, 7th and 8th decades. Associations have been suggested with breast feeding, use of contraceptives, autoimmune disorders, alpha-1 antitrypsin deficiency and hyperprolactinemia[5, 8]. Diagnostic tools such as ultrasound, mammogram, true-cut biopsy, fine needle aspiration biopsy and contrast-enhanced MRI can be helpful in diagnosis. A true-cut biopsy is recommended to clarify the diagnosis. Other entities such us malignancy, fungal, bacterial and parasitic infections, autoimmune conditions, and other granulomatous diseases such as tuberculosis and sarcoidosis should be excluded. The diagnostic histopathologic changes include chronic granulomatous lobulitis without caseating necrosis plus giant cells, leucocytes, epitheloid cells, macrophages and micro-abscesses.
IGM is usually a diagnostic and therapeutic dilemma, which initially can mimic other conditions and is a diagnosis of exclusion. The clinical presentation frequently suggests breast abscess or breast cancer[9, 12]. Some authors have mentioned that more than 50% of cases can mimic breast carcinoma. The patient reported in this article started her clinical picture with unspecific findings of an expanding mass and surrounding local inflammation, as is usually described[5, 8]. As with most patients with IGM the initial presentation leads to the use of antibiotics. In this patient, symptoms developed to suggest an infective mastitis or possibly an abscess. As her condition worsened, empiric antibiotic treatment was started.
When the diagnosis suggests mastitis, the lack of response in patients suffering from this condition can lead to different antibiotic combinations and the uncertain treatment could lead to complications, as was the case of this patient (“Red man” syndrome and allergic reaction to Clindamycin).
As the study of patients with this clinical presentation requires exclusion of other causes of mastitis and malignancy, obtaining core specimens by true-cut biopsy for pathological study is paramount. In this case, the pathology ruled out neoplasms but reported abscesses with positive bacterial cultures leading to antibiotic treatments. However, the presence of a granuloma and giant cells suggested IGM. Having a granuloma with central necrosis and evidence of a calcified pulmonary nodule on x-ray made tuberculosis a possible etiology, but the different cultures and stains were always negative for tuberculosis and her previous history was noncontributory for this diagnosis.
In the case presented, the patient emphatically refused to accept the radical surgical treatment that was proposed to her, her tenacity made her maintain her wish for conservative management, and her desperation lead her to look for further treatment in Colombia that helped to stabilize her situation. There is still debate about the treatment for this condition but it should initially be non-operative[1, 5]. Conservative treatment with close observation has been suggested. In most of the cases once infectious conditions have been excluded oral steroid therapy is required[1, 8]. Most of the evidence that supports these interventions comes from original articles and case reports. Anti-inflammatory medications, systemic antibiotics, methotrexate, colchicine, local infiltrations and ulcers wound care are also helpful. One study documented relapse in 50% of cases after discontinuing corticosteroid treatment. In those refractory to treatment or which recur, methotrexate or azathioprine are recommended. In more difficult cases immunosuppressive management and complete surgical excision can be considered.