Although the incidence of TB has stabilized or declined in most world regions, it is increasing in Africa, Southeast Asia, and the Eastern Mediterranean, fuelled by the HIV pandemic. More than 4,000 people died daily from TB-related illnesses in 2005. TB is a major cause of childhood morbidity and mortality in these developing countries, and there is an urgent need for rapid and definitive modalities for mycobacterial diagnosis in children. This prospective study in Tygerberg Hospital, Cape Town, South Africa, evaluates the ability of fine needle aspiration biopsy (FNAB) to diagnose mycobacterial lymphadenitis in children, using cytomorphology, autofluorescence on Papanicolaou stained smears, Ziehl-Nielsen (ZN) staining and/or culture. FNABs were performed on 200 children, and 25 (12.5%) aspirates were inadequate. Cultures were positive in 79/175 (45%); Mycobacterium tuberculosis was identified in 61 and Mycobacterium bovis BCG in 18 cases. Using culture as the gold standard, the concordance of the different techniques was as follows: cytomorphology 70%, ZN staining 73%, and autofluorescence 68%. Using an alternative gold standard (culture positive and/or suggestive cytomorphology plus positive autofluorescence or ZN smear), the "true" diagnostic performance of the various techniques was as follows: cytomorphology-sensitivity 78%, specificity 91%, positive predictive value (PPV) 93%, ZN staining - sensitivity 62%%, specificity 97%, PPV 97%; autofluorescence-sensitivity 67%, specificity 97%, PPV 97%; and culture-sensitivity 75%, specificity 100%, and PPV 100%. FNAB was shown to provide a rapid and definitive diagnosis in the majority of cases of suspected tuberculous lymphadenitis in children, based on cytomorphology and identification of the organism.

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Papulonecrotic tuberculid (PNT), a form of cutaneous tuberculosis (TB), is uncommon in children. We identified eight children (six girls and two boys) with PNT. Their ages ranged from 19 to 139 months (median 47.5 months, mean:64.75 months). Skin lesions had been present for 2-24 weeks (median: 4 weeks) before diagnosis. All patients displayed scattered papulo- and/or pustulonecrotic lesions on the limbs, and the ears were involved in six patients. Lesions healed with varioliform scars. Associated pulmonary TB was present in seven patients. Additional clinical findings included fever (n = 4), hepatomegaly (n = 4), lymphadenopathy (n = 3), phlyctenular conjunctivitis (n = 3), and splenomegaly (n = 2). Histology of eight biopsies showed ulceration (n = 6), dermal necrosis (n = 6) (follicle-centered in two), granulomatous inflammation (n = 6) (palisading granuloma-like in three), superficial and deep infiltrate of lymphocytes (n = 7), erythrocyte extravasation (n = 7), and subepidermal edema (n = 3). Vasculitis was not a feature. A Ziehl-Neelsen stain was negative in all. Glycosaminoglycans were not increased. Immunohistochemistry found a predominance of T lymphocytes, macrophages, a few antigen-presenting cells, and no B lymphocytes, consistent with a type IV hypersensitivity reaction. Polymerase chain reaction (PCR) performed on deparaffinized tissue identified M. tuberculosis DNA in one biopsy. All patients received combination anti-TB treatment for 6 months. Six patients were compliant and were followed up for 6-30 months. Skin lesions and pulmonary TB healed in all. PNT in children resembles the adult form, but phlyctenular conjunctivitis and associated TB are more common, scrofuloderma and concomitant erythema induratum of Bazin are unusual, and vasculitis is not found. In cases where M. tuberculosis DNA can be confirmed with PCR, papulonecrotic TB is perhaps the more appropriate nomenclature.