title: Histopathological spectrum of cutaneous tuberculosis and non-tuberculous mycobacterial infections.
abstract: The non-specific clinical findings and variable histopathological features of cutaneous tuberculosis and non-tuberculous mycobacterial infections often make it difficult to establish a diagnosis and initiate appropriate therapy. We investigated 25 patients diagnosed with mycobacterial infections of the skin in Hanyang University Hospital between 2001 and 2011. Skin biopsy specimens were re-evaluated by various histopathological criteria and molecular studies. To identify the mycobacteria, we performed staining for acid-fast bacilli and also completed polymerase chain reaction analysis. The non-tuberculous mycobacterium species were identified by genetic sequencing of formalin-fixed, paraffin-embedded tissues. Immunocompromised status was more frequent in non-tuberculous mycobacterial infections than in tuberculosis (p = 0.017) while disease duration was longer in tuberculosis (p = 0.026). Microscopically, neutrophil infiltration, interstitial granuloma, small vessel proliferation and increased numbers of bacilli were found to be associated with non-tuberculous mycobacterial infections (all p < 0.05). In contrast, giant cells, plasma cells, tuberculoid granulomas and necrosis were associated with tuberculosis (all p < 0.05). There were no species-specific histopathological findings in non-tuberculous mycobacterial infections. The significant histopathological differences between cutaneous tuberculous and non-tuberculous mycobacterial infections are helpful in considering differential diagnoses. In addition, molecular techniques together with clinico-pathological findings may assist in making accurate diagnoses of cutaneous non-tuberculous mycobacterial infections.
authors.affiliation: Department of Pathology, College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Kyueng-Whan
authors.initials: KW
authors.lastname: Min
authors.forename: Joo Yeon
authors.initials: JY
authors.lastname: Ko
authors.forename: Chan Kum
authors.initials: CK
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006101:Granuloma, Giant Cell / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000235:genetics / Q000382:microbiology / Q000473:pathology*; D020556:Neutrophil Infiltration; D009170:Nontuberculous Mycobacteria / Q000235:genetics; D010950:Plasma Cells / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods; D012189:Retrospective Studies; D014382:Tuberculosis, Cutaneous / Q000235:genetics / Q000382:microbiology / Q000473:pathology*