Hepatic nontuberculous mycobacterial granulomas in patients with cancer mimicking metastases: an analysis of three cases

Detection of Mycobacterium tuberculosis in a patient with suspected cystic echinococcosis: a case report

BACKGROUND

Tuberculosis is a global health issue affecting millions of people worldwide. While pulmonary tuberculosis is common, hepatic tuberculosis is rare and accounts for less than 1% of cases. Diagnosis is challenging owing to nonspecific symptoms and its ability to mimic other hepatic diseases.

CASE PRESENTATION

This case report describes a 62-year-old male healthcare worker, originally from the Philippines and of Filipino ethnicity, who was initially suspected to have cystic echinococcosis, an epidemiologically uncommon zoonotic disease in both Austria and the Philippines. Echinococcosis was excluded by ultrasound and serology. Several other differential diagnoses, including pyogenic and amoebic liver abscesses, brucellosis, hepatocellular carcinoma, and hepatic metastases of other malignancies, were also ruled out. Ultimately, a biopsy of the liver lesion was performed, and the tissue tested positive for Mycobacterium tuberculosis complex by polymerase chain reaction. The patient was successfully treated with a standard 6-month antitubercular combination therapy.

CONCLUSION

This case highlights the potential for tuberculosis to affect any organ system, including the liver, particularly in patients from high-burden regions.

Non-Tuberculosis Mycobacterium Periprosthetic Joint Infections Following Total Hip and Knee Arthroplasty: Case Series and Review of the Literature

OBJECTIVE

Periprosthetic joint infection (PJI) caused by non-tubercular mycobacteria (NTM) is uncommon but catastrophic. However, conclusive clinical data on PJI caused by NTM are lacking. In this case series and systematic review, the clinical manifestations, diagnosis, and management of NTM PJI are summarized and analyzed.

METHODS

From 2012 to 2020, we retrospectively analyzed consecutive PJI cases caused by NTM in our institution. A literature review was also conducted from January 2000 to December 2021, utilizing the PubMed, MEDLINE, Cochrane Library, and EMBASE databases to identify all reported NTM-induced PJI cases. The clinical characteristics, demographics, pathogen identification, treatment protocols, and prognosis of NTM PJI were summarized and analyzed.

RESULTS

In this retrospective analysis, seven patients infected with NTM following total joint arthroplasty at our institution were included, including six cases of PJI caused by NTM and one case of septic arthritis (SA) caused by NTM. There were six men and one woman, and their average age was 62.3 years. The average interval between TJA and PJI onset was 4 months. The preoperative serological markers, including the mean ESR (51 mm/h), CRP (4.0 mg/dL), fibrinogen (5.7 g/L), and D-dimer (1.1 g/L), were increased. Six patients underwent staged revision surgery, and one patient with SA received antibiotic-loaded bone cement beads to treat the infection. After an average of 33 months of observation following surgical intervention, none of the patients showed any symptoms of infection recurrence. From 2000 to 2021, 68 patients with NTM PJI were found in 39 studies in the published literature. Reinfections occurred within 1 year after arthroplasty in more than half (53.2%) of the patients. M. fortuitum and M. abscesses were the most prevalent rapidly growing mycobacteria (RGM) in all PJI patients, whereas Mycobacterium avium intracellulare (MAC) was the most prevalent slowly growing mycobacterium (SGM). The corresponding antibiotics were amikacin and ethambutol. The rate of culture-negative without specific clinical symptoms was as high as 36.4% (12/33), while 45% (18/40) utilized additional diagnostic techniques such as NGS. A final clinical follow-up record was available for 59 patients (86.7%; mean follow-up period, 29 months), and 10.1% of patients failed to respond to treatment.

CONCLUSION

Orthopaedic surgeons should consider NTM in patients with negative routine cultures who are at risk for Mycobacterium infection. Treatment options rely on the accurate result of microbiologic identification and drug sensitivity testing, and to achieve this, it may be necessary to send multiple culture specimens, extend the culture time, and change the culture medium. Every effort should be made to identify NTM and its various subtypes through modern diagnostic tools if necessary.

Primary tubercular granulomatous hepatitis presenting as fluctuating jaundice

Granulomatous hepatitis is an uncommon presentation of tuberculosis (TB). It is even more peculiar to have TB confined to the liver alone with no pulmonary or a disseminated form. In either form, there is the usual presentation of nonprogressive cholestatic jaundice, but no documented case with fluctuating jaundice in the literature was found. In order to highlight this rare presentation aiding the right diagnosis, we present one such case of a 46-year-old woman with no known comorbidities, who complained of fluctuating and painless type of jaundice, associated with fatiguability, pruritus, and weight loss. Preliminary blood investigations showed anemia and cholestatic pattern of jaundice. Ultrasonography and computed tomography imaging showed hepatomegaly with heterogeneous texture. Magnetic resonance cholangiopancreatography further revealed features of cholecystitis with hepatic ducts near proximal common bile duct showing postinflammatory change. The periampullary region was normal. Sputum acid-fast staining and cartridge-based nucleic acid amplification test were negative. Eventually, liver biopsy was done which showed caseating granulomas with Langhans giant cells. The tissue was abundant in acid-fast bacilli. The patient was started on a 9-month course of first-line Antitubercular treatment (ATT) and responded well. Fluctuating jaundice is a rare and undocumented presentation of primary hepatic TB and can cause diagnostic dilemmas.

Drug Resistance in Nontuberculous Mycobacteria: Mechanisms and Models

The genus Mycobacteria comprises a multitude of species known to cause serious disease in humans, including Mycobacterium tuberculosis and M. leprae, the responsible agents for tuberculosis and leprosy, respectively. In addition, there is a worldwide spike in the number of infections caused by a mixed group of species such as the M. avium, M. abscessus and M. ulcerans complexes, collectively called nontuberculous mycobacteria (NTMs). The situation is forecasted to worsen because, like tuberculosis, NTMs either naturally possess or are developing high resistance against conventional antibiotics. It is, therefore, important to implement and develop models that allow us to effectively examine the fundamental questions of NTM virulence, as well as to apply them for the discovery of new and improved therapies. This literature review will focus on the known molecular mechanisms behind drug resistance in NTM and the current models that may be used to test new effective antimicrobial therapies.

A Rare Case of Disseminated Mycobacterium avium-intracellulare Presenting as Proctitis

Mycobacterium avium intracellulare (MAI) infections are common in Human Immuno-deficiency Virus (HIV) positive patients. MAI infection can have localized or disseminated presentation, patients with low CD4 count presenting with disseminated infection. Fever, abdominal pain, diarrhea, and weight loss are generally the presenting symptoms of disseminated MAI. We present a rare case of a patient with HIV and low CD4 count presenting with proctitis as manifestation of disseminated MAI infection. A 25 year-old-man with HIV came to the emergency room (ER) with complaints of intermittent rectal bleeding for two months. His CD4 count was less than 20 cells/µL. He was MSM (men having sex with men) and has receptive anal intercourse with men. His stool work-up was unrevealing for infectious etiology. Swabs for gonorrhea and chlamydia were negative. Colonoscopy revealed erythematous, congested, friable rectal mucosa with two superficial ulcers. Biopsies of the ulcer were positive for acid fast staining bacteria and the culture grew MAI. His blood culture was negative for growth of acid-fast bacteria (AFB). However, liver biopsy performed for elevated alkaline phosphatase of 958 units/L revealed noncaseating granuloma. Gastro-duodenoscopy with duodenal biopsy did not reveal any mucosal abnormality. He was managed as with disseminated MAI infection using clarithromycin, ethambutol, and rifabutin in addition to HAART therapy. Interval Colonoscopy in 20 months showed resolution of rectal ulcer. The gut is often involved in patients with disseminated MAI infection, with the duodenum being the most common site. MAI infection should be suspected as possible etiology for proctitis in HIV positive patient with low CD4 count, as proctitis, though infrequent can be the sole presentation for disseminated MAI infection in patients with HIV and low CD4 count.