Detection of Corynebacterium kroppenstedtii in Granulomatous Lobular Mastitis Using Real-Time Polymerase Chain Reaction and Sanger Sequencing on Formalin-Fixed, Paraffin-Embedded Tissues

Abstract

Context.— Associations between granulomatous lobular mastitis (GLM) and Corynebacterium kroppenstedtii have been reported since 2002, but large scale studies to assess the actual prevalence of this bacterium in GLM have not been performed. Objective.— To assess the prevalence of C kroppenstedtii in GLM using real-time polymerase chain reaction and Sanger sequencing. Design.— We analyzed formalin-fixed, paraffin-embedded tissues from 67 cases of GLM by sequential DNA amplification and sequencing to assess the rate of C kroppenstedtii detection in GLM. A retrospective analysis including patient demographics, history of pregnancy and lactation, clinical signs and symptoms, radiographic findings, histologic pattern, Gram stain results, and microbial cultures was performed on 67 cases of GLM. In addition, 10 cases of nongranulomatous breast abscess were included as controls. Results.— C kroppenstedtii 16S rRNA SYBR real-time polymerase chain reaction was positive on formalin-fixed, paraffin-embedded tissues from 46 of 67 (68.7%) GLM cases, while all control cases were negative. Among the positive cases, the majority showed features of cystic neutrophilic granulomatous mastitis. Conclusions.— C kroppenstedtii was highly prevalent in GLM cases and was not found to be associated with nongranulomatous breast abscess in our study (P < .001).

Granulomatous Mastitis with Corynebacterium Infection

“…We found 16 English articles, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and 4 Japanese ones (Table 1). [31][32][33][34] Corynebacterium (C.) kroppenstedtii was detected most frequently, followed by C. tuberculostearicum.…”

“…19 Therefore, recent articles indicated not only bacterial culture but also real-time polymerase chain reaction (PCR) and formalin-fixed, paraffin-embedded (FFPE) biopsy specimens analysis for detecting pathogenically Corynebacterium spp. 18,25 It is reported that real-time PCR of C. kroppenstedtii from FFPE sections was useful (39-69% positive) in IGM cases. 18,25 The histopathological feature is granulomatous inflammation with dense exudation of lymphocytes, plasma cells, epithelioid histiocytes, multinucleated giant cells and neutrophils.…”

“…18,25 It is reported that real-time PCR of C. kroppenstedtii from FFPE sections was useful (39-69% positive) in IGM cases. 18,25 The histopathological feature is granulomatous inflammation with dense exudation of lymphocytes, plasma cells, epithelioid histiocytes, multinucleated giant cells and neutrophils. The inflammation is accentuated in the lobule and/or around the mammary duct.…”

Idiopathic Granulomatous Mastitis: Diagnosis and Histopathologic Features, A Review

“…12 The most common isolates are C. kroppenstedtii, followed by C. amycolatum, and C. tuberculostearicum. [35][36][37] The bacillary microorganisms can be identified in the empty spaces by the high-power examination of the lesion, though negative cases are common due to the scarcity of bacteria and poor Gram staining. (38) According to Paviour et al, Corynebacterium could be proposed as a pathogenetic factor in IGM.…”

The Emerging Role of Corynebacteria in the Pathogenesis of Granulomatous Lobular Mastitis

“…We recently reported our study assessing the prevalence of Corynebacterium kroppenstedtii in FFPE tissues by real-time PCR in a large cohort of GLM cases, the largest study of this type to date. 15 In this study, we included FFPE tissues from 67 cases fulfilling the histologic criteria of GLM as well as 10 cases of non-granulomatous breast abscess as controls. DNA was extracted from FFPE tissues of all 67 GLM cases as well as the 10 control cases and amplified SYBR real-time PCR with primers specifically targeting the Corynebacterium kroppenstedtii 16S rRNA gene region.…”