Granulomatous Mastitis Occurring during Pregnancy: A Case Report

Clinical and microbiological characteristics of granulomatous mastitis caused by Corynebacterium species: A case series

Corynebacterium species are an important cause of granulomatous mastitis (GM). Although there have been worldwide reports of infections caused by Corynebacterium kroppenstedtii, few cases of C. tuberculostearicum GM have been reported. We conducted a retrospective study to investigate the clinical and microbiological characteristics of GM caused by Corynebacterium spp. between January 1, 2014, and May 31, 2024. During the study period, six patients with GM were identified, including four cases of C. kroppenstedtii GM and two cases of C. tuberculostearicum GM. All patients were female with a median age of 32 years (range: 18-50 years). All patients underwent surgical drainage and were treated with clarithromycin. The minimum inhibitory concentration (MIC) values for various antimicrobial agents, including azithromycin, clarithromycin, ciprofloxacin, clindamycin, and trimethoprim-sulfamethoxazole, were higher for C. tuberculostearicum than for C. kroppenstedtii. Additionally, MALDI-TOF MS and 16s rRNA gene sequencing accurately identified C. kroppenstedtii and C. tuberculostearicum. Accurate identification of lipophilic Corynebacterium spp. is important for antibiotic treatment selection. If clinicians suspect lipophilic Corynebacterium spp. infection, particularly GM, they should ask the microbiology laboratory to test for lipophilic Corynebacterium spp.

Granulomatous mastitis during pregnancy with sudden onset of gait difficulty and erythema nodosum: A case report and review of the literature

Granulomatous mastitis (GM), a benign inflammatory disease of the breast, often mimics breast cancer on presentation. We present a case of GM during pregnancy manifesting as a breast mass, sudden onset of plantar pain, and erythema nodosum (EN). A 31-year-old pregnant Japanese woman, gravida 2, para 1, was referred to our hospital with severe plantar pain on both soles, causing difficulty walking. This pain worsened and EN appeared on both lower legs, followed by a left breast mass. Ultrasound findings suggested malignancy; however, aspiration biopsy confirmed GM. Her arthritis and EN resolved 2 days after commencing oral prednisolone and her walking improved. EN with/without arthritis is commonly associated with GM, especially during pregnancy. The described manifestations with a breast mass are suggestive of this diagnosis.

Idiopathic Granulomatous Mastitis, Erythema Nodosum, and Polyarthritis

Idiopathic granulomatous mastitis (IGM) is an inflammatory-mediated rare disease that can be linked to rare manifestations. Erythema nodosum (EN) and polyarthritis, seen in a multitude of autoinflammatory and autoimmune diseases, have been rarely linked to IGM. Despite the cause of IGM being unclear, Corynebacterium infections are thought to play a role in the pathophysiology of IGM. Unusually, IGM has a relapsing and remitting course, which also applies to its systemic manifestations. As such, we present a case of IGM in a middle-aged lady who was initially thought to have Corynebacterium-containing unilateral abscesses for which drainage was performed. However, several abscesses devoid of bacterial growth started recurring, and the disease course was complicated by EN and polyarthritis. IGM, EN, and polyarthritis eventually resolved and were managed with symptomatic treatment.

Idiopathic granulomatous mastitis: A challenging case report and comprehensive review of the literature

INTRODUCTION AND IMPORTANCE

Idiopathic granulomatous mastitis is an uncommon, long-lasting inflammatory condition of the female breast. It is characterized by the development of a painful breast mass that gradually increases in size. This condition is benign and its cause is unknown. It primarily affects women of childbearing age who have a history of pregnancy and breastfeeding. The main feature of idiopathic granulomatous mastitis is the presence of chronic inflammation in the breast.

CASE PRESENTATION

We report a 36-year-old woman with a history of pregnancy and breastfeeding presented with pain and swelling of the right breast. Physical examination revealed a mass with redness and retraction of the nipple. Imaging revealed localized density and hypoechoic areas with collection, suggesting granulomatous mastitis. A biopsy confirmed the diagnosis. The abscess was drained through a small incision performed under local anesthesia. Treatment with corticosteroids resulted in significant improvement, with complete resolution after one month.

CLINICAL DISCUSSION

A comprehensive evaluation of potential causes is necessary to confirm the diagnosis of idiopathic granulomatous mastitis. Histologically, it is distinguished by the predominant presence of neutrophils and the absence of caseous necrosis. Treatment remains controversial, with recent literature supporting the efficacy of conservative management with steroid and immunosuppressive therapy, leaving surgical excision for complicated and refractory cases.

CONCLUSIONS

Idiopathic granulomatous mastitis is an uncommon breast condition where the exact causes and recommended treatment approaches are not well-defined. It is important to consider this condition in women who are in their reproductive years.