Case of disseminated cutaneous Mycobacterium chelonae infection mimicking cutaneous vasculitis

Nasal Septal Perforation and Widespread Skin Lesions Caused by Mycobacterium chelonae Infection Mimicking Granulomatosis with Polyangiitis

Mycobacterium chelonae, a rapidly growing mycobacterium found in the natural environment, is known to cause localized lesions in the skin, soft tissue, and bone through traumatic inoculation, but widespread lesions are uncommon. We herein report an immunocompromised 79-year-old man suspected of having polyangiitis granulomatosis due to weight loss, epistaxis, and nasal crusts with impending septal perforation who was subsequently diagnosed with mucocutaneous and bone disease caused by widespread M. chelonae infection. Given these findings, clinicians should be aware of the tendency to develop unusual widespread lesions in immunocompromised patients, which can present a clinical picture similar to systemic vasculitides, such as granulomatosis with polyangiitis.

Subcutaneous vacuoles with suppuration and granulomas: a histological clue to atypical mycobacterial infection

An 83-year-old woman was referred to the Dermatology department with a papular eruption on her left arm, occurring below the scar site of a malignant melanoma in situ, which had been excised 6 months previously. On physical examination, multiple, tender, violaceous papules and nodules inferior to the scar were noted, with central pustules in some of the lesions.

Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Small vessel vasculitis secondary to Mycobacterium chelonae

Mycobacterial infection can be seriously debilitating and challenging to diagnose. The infection can mimic vasculitis associated with positive anti-neutrophilic cytoplasmic autoantibodies (ANCA). This clinical scenario is exemplified with a well-studied case of a 63-year-old Caucasian man with uncontrolled diabetes and ulcerative colitis on immunosuppressive agents. The patient was hospitalized for 3 months with worsening painful hand ulcerations. Primary vasculitis was first suspected, but the patient was later diagnosed with vasculitis secondary to Mycobacterium chelonae infection. Report includes discussion on sequence of testing which led to the diagnosis. After proper diagnosis and change to proper antibiotics, the patient's vasculitis improved over time. It is our hope that this report further raises awareness of mycobacterial infection as a mimicker of vasculitis. We also provide a review of relevant literature on non-tuberculosis mycobacterial (NTM) infection including a review of 22 articles and 12 cases found in the literature. The salient features of the literature review include that 10 of the 12 cases were patients who had risk factors of immunosuppression due to medications, and all patients were infected by mycobacterium causing skin vasculitis. After given the proper directed antibiotic treatment, 11 of the 12 patients had a reported improved outcome.

Histopathological Features of Mycobacterium chelonae Infection in Two Farmed Japanese Pufferfish (Takifugu rubripes)

Granulomatous lesions were observed in the swim bladder, kidney, spleen and gills of two farmed Japanese pufferfish (Takifugu rubripes) infected with Mycobacterium chelonae. Three types of lesions were noted: unencapsulated clusters of epithelioid cells without central necrosis (type 1), encapsulated granulomas without central necrosis (type 2) and encapsulated granulomas with central necrosis (type 3). Type 3 lesions occurred most frequently in the swim bladder, while type 1 and type 2 lesions occurred frequently in the kidney and spleen, and the gills exhibited mostly type 1 lesions. This suggests that the lesions in the swim bladder were more fully developed than those occurring elsewhere and that the swim bladder may be more susceptible to infection with M. chelonae. This is the first report describing the histopathological features of M. chelonae infection in Tetraodontidae.

Necrotizing osteomyelitis in a man with disseminated Mycobacterium chelonae infection

Cases of disseminated nontuberculous mycobacterial (NTM) infection are difficult to treat. We encountered an elderly man with disseminated Mycobacterium chelonae infection. The clinical evaluation and treatment of patients with this type of systemic infection pose unique challenges. Disseminated NTM infection with bone involvement often requires surgical intervention in addition to antimicrobial therapy.

[Cutaneous infections: Pathologist's role in unusual or atypical situations]

In infectious pathology, the gold standard consists of the detection of the pathogen within the sample. Identification of the pathogen is often difficult despite the presence of few and inexpensive tools, such, as special stain, immunohistochemistry, or in situ hybridization specific of the pathogen. In infectious pathology, there are morphological signs, which can guide us towards an etiology. We present some clinicopathological examples illustrating rare or unusual situations in cutaneous infectious pathology.

Mycobacteria

The immunocompromised host is at increased risk of Mycobacterium tuberculosis complex and nontuberculous mycobacteria infection. Although Mycobacterium tuberculosis complex is a significant mycobacterial pathogen, nontuberculous mycobacteria causes substantial disease in those with suppressed immune responses. Mycobacterial infections can cause significant morbidity and mortality in this patient population, and rapid identification and susceptibility testing of the mycobacterial species is paramount to patient management and outcomes. Mycobacterial diagnostics has undergone some significant advances in the last two decades with immunodiagnostics (interferon gamma release assay), microscopy (light-emitting diode), culture (automated broth-based systems), identification (direct PCR, sequencing and matrix-assisted laser-desorption ionization–time of flight mass spectrometry) and susceptibility testing (molecular detection of drug resistance from direct specimens or positive cultures). Employing the most rapid and sensitive methods in the mycobacterial laboratory will have a tremendous impact on patient care and, in the case of Mycobacterium tuberculosis complex, in the control of tuberculosis.