1 - Unidade de Infeciologia Pediátrica, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisboa;
2 - Departamento de Microbiologia, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisboa;
3 - Unidade de Doenças Infeciosas, Instituto Nacional de Saúde Doutor Ricardo Jorge, Porto;
4 – Unidade de Imunodeficiências Primárias, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisboa.
- reunião internacional: ESPID 2023, Lisboa
Background: Nontuberculous mycobacteria (NTM) are an important cause of cervical lymphadenitis in immunocompetent children. Most cases are caused by Mycobacterium avium complex. However, Mycobacterium kansasii remains one of the most relevant species of NTM.
Case Presentation Summary: A previously healthy 6-year-old girl was referred to our institution due to a 3-month history of hard adherent unilateral cervical lymphadenopathy. Other symptoms were absent, animal contact or recent travel were denied, and her immunizations did not include BCG. Blood work showed elevated erythrocyte sedimentation rate (25 mm/h), with normal complete blood cell count, C reactive protein and aminotransferases. HIV, CMV, EBV, toxoplasmosis were excluded. QuantiFERON®-TB gold test (QTF) was positive, chest X-ray was unremarkable, and the neck ultrasound revealed a right adenopathic conglomerate (52 mm) and the abdominal ultrasound mesenteric adenopathies (7 mm) and small bowel intussusception. Lymph node’s biopsy revealed a caseous granuloma and acid-fast bacilli smear and nucleic acid amplification tests were negative. Tuberculous lymphadenitis was considered, and isoniazid, rifampicin, pyrazinamide, ethambutol [HRZE] were initiated. Biopsy’s cultural exam isolated M. kansasii, sensitive to R, moxifloxacin and clarithromycin, which motivated pyrazinamide discontinuation and treatment with HRE, so far for five months, with gradual improvement. Immunological study is ongoing.
Learning Points/Discussion: The clinical syndromes and radiologic findings of M. kansasii infection are usually indistinguishable from those of M. tuberculosis, so microbiological confirmation is required. Furthermore, QTF may be positive in patients infected with M. kansasii, confounding the diagnosis, as it firstly happened in this case. There is limited evidence to guide treatment of M. kansasii extra-pulmonary disease. We decided to treat this presumed immunocompetent child with extrapulmonary disseminated infection with HRE for a minimum of six months, being the duration decided according to clinical and imagiological evolution.
Palavras Chave: Caseous granuloma; Mycobacterium kansasii; Nontuberculous mycobacteria