Almost all forms of TB involve regional lymphatics and nodes. This section will focus on extrathoracic lymph nodes and, specifically, peripheral TB lymphadenitis.
Mycobacterial involvement of the lymph glands can be secondary to infection from Mycobacterium tuberculosis (M. tuberculosis) as well as other non-TB mycobacteria (NTM).97 Unilateral cervical chain involvement is the most common site of TB lymphadenitis (45 to 80%) but lymphadenitis can occur in the supraclavicular and axillary regions, as well as a variety of other nodal sites.98–100 Presentation can be at a single nodal site or in multiple sites.
In general, the disease is most often indolent, and the patient usually presents with an isolated, unilateral, nontender neck mass.98 The term “scrofula” has been used historically to describe TB involvement of a cervical lymph node with sinus tract formation or ulceration of the overlying skin. Non-nodal symptoms are rare, except in people with HIV.101,102
Fine-needle aspiration (FNA) biopsy of affected lymph nodes is a useful initial procedure (see Table 1). If FNA is nondiagnostic, the highest-yield procedure is an excisional lymph node biopsy. If there is high suspicion for an alternate diagnosis (eg, lymphoma), clinicians may choose to pursue excisional biopsy as the initial diagnostic test. Incisional biopsies are discouraged for initial testing because of the risk of sinus tract formation at the biopsy site in mycobacterial disease.103 Swabs are discouraged because of the limited material obtained and because the hydrophobic nature of the mycobacterial cell wall inhibits the transfer of organisms from the swab to the culture media.104 Specimens should be submitted for both mycobacteriologic (smear, culture and NAAT) and histopathologic analysis. Differentiation of M. tuberculosis from M. avium complex is important, as treatment of the 2 conditions is different.
3.1.1. TB lymphadenitis treatment
Two small randomized controls trials that compared 6- versus 9-month treatment courses did not report any difference in treatment completion or relapse rates.105,106 Three systematic reviews that also included observational studies reported the same findings.107–109
Recommendation
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We conditionally recommend six months of standard anti-TB therapy for treating drug-susceptible TB lymphadenitis (poor evidence).
In up to 23% of patients, nodes can appear afresh or enlarge during treatment, possibly as an immune response. This usually will resolve without change in regime or additional therapy and should not be considered evidence of treatment failure.110 At the end of treatment, up to 34% of patients may be left with residual nodes and, if after treatment, the nodes enlarge or reappear, this is usually transient.107 Such events do not necessarily imply relapse, but repeat FNA for mycobacterial culture should be considered to assess this possibility if the nodes are persistent.111,112
Good practice statement
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In TB lymphadenitis, surgical/drainage procedures, other than diagnostic, should be reserved for the relief of discomfort caused by enlarged nodes or tense, fluctuant nodes.
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