The Clinicopathological Features of Mediastinal Tuberculous Lymphadenitis in Cancer Patients and the Diagnostic Role of Endobronchial Ultrasound

Abstract

IntroductionMediastinal lymphadenopathy in cancer patients can be of both malignant and non-malignant (including infectious) etiology. Tuberculosis (TB) is an important differential in this regard, particularly in regions with high TB endemicity. ObjectivesTo determine the incidence and clinical characteristics of mediastinal tuberculous lymphadenitis (MTBLA) in cancer patients of a TB-endemic region, and the diagnostic role of endobronchial ultrasound (EBUS) guided transbronchial needle aspiration (TBNA) in such patients, utilizing both cytopathological and microbiological parameters for diagnosing TB. Materials and methodsWe retrospectively analyzed the relevant clinical data of all cancer patients diagnosed with MTBLA after undergoing EBUS-TBNA at our center, between July 2013 till July 2018 (total five years). The diagnostic yield, sensitivity and specificity of cytopathological and microbiological investigations (including TB culture and Mycobacterium tuberculosis Gene Xpert assay) for diagnosis of MTBLA were determined. ResultsOf the total 493 cancer patients, MTBLA was diagnosed in 54 (11%), with mean age of 48 ± 12 years, and predominantly male gender (59.3%). Thirty-three (61.1%) patients were clinically asymptomatic at the time of presentation, while cough was reported by 13 (24.7%) patients and weight loss, shortness of breath and fever by only six (11.1%), six (11.1%) and five (9.2%) patients, respectively. Total 53% had an underlying gastrointestinal malignancy. Chest imaging revealed bilateral versus unilateral hilar lymph node enlargement in 32 (59.3%) against 22 (40.7%) patients, respectively, while only 14 (25.9%) had accompanying lung parenchymal findings. Granulomatous TBNA cytology was detected in 41 (77.3%) patients, giving a diagnostic yield of 70.3% for MTBLA, with an estimated sensitivity and specificity of 79.2% and 99%, respectively. TB culture and Gene Xpert had a respective sensitivity of 48% and 53%, with the combined diagnostic yield of 64.8%. Treatment response was achieved in 51 (94%) patients, based on which EBUS was estimated to have sensitivity and specificity of 89% and 99% respectively, with no reported complications. ConclusionMediastinal TB can have diverse manifestations among cancer patients and can often be clinically occult, with overlapping radiological impressions. EBUS-TBNA can serve as a safe and reliable diagnostic tool in this regard.

Xpert MTB/RIF in the Diagnosis of Mediastinal Tuberculous Lymphadenitis by Endoscopic Ultrasound-Guided Needle Aspiration Techniques: A Systematic Review and Meta-Analysis

“…282 potential studies were selected for screening, 48 were suitable for full-text review and, then, 40 articles were excluded. A total of 8 studies [13,17,[20][21][22][23][24][25] met the inclusion criteria (Fig. 1).…”

“…The 8 selected articles were published between 2014 and 2021 [13,17,[20][21][22][23][24][25]; they describe studies carried out between 2010 and 2018 (Table 1). The epidemiological design of these observational studies was clearly reported in all studies: 2 (25%) were cross-sectional [17,22], 1 (12.5%) was prospective [20], and 5 (62.5%) were retrospective cohort studies [13,21,[23][24][25].…”

“…The 8 selected articles were published between 2014 and 2021 [13,17,[20][21][22][23][24][25]; they describe studies carried out between 2010 and 2018 (Table 1). The epidemiological design of these observational studies was clearly reported in all studies: 2 (25%) were cross-sectional [17,22], 1 (12.5%) was prospective [20], and 5 (62.5%) were retrospective cohort studies [13,21,[23][24][25]. The clinical centers where the studies were conducted were located in 4 countries: 5 (62.5%) in India [17,20,21,24,25], 1 (12.5%) in the United Kingdom [13], 1 (12.5%) in South Korea [23], and 1 (12.5%) in Pakistan [22].…”

“…The epidemiological design of these observational studies was clearly reported in all studies: 2 (25%) were cross-sectional [17,22], 1 (12.5%) was prospective [20], and 5 (62.5%) were retrospective cohort studies [13,21,[23][24][25]. The clinical centers where the studies were conducted were located in 4 countries: 5 (62.5%) in India [17,20,21,24,25], 1 (12.5%) in the United Kingdom [13], 1 (12.5%) in South Korea [23], and 1 (12.5%) in Pakistan [22]. All the studies were monocentric [13,17,[20][21][22][23][24][25].…”

Elucidating the Etiologies of 18F-fluorodeoxyglucose-Avid Mediastinal Lymph Nodes Among Cancer Patients in a Tuberculosis-Endemic Region Using Endobronchial Ultrasound

“…The risk stratification for malignancy appears to be improved if other characteristics such as nodal size and SUV of primary malignant mass are considered simultaneously [13]. However, such an approach has rarely been replicated in TB-endemic demographics, where TB is an important cause of mediastinal lymphadenopathy mimicking malignancy [15][16][17]. In general, there is a dearth of studies on cancer patients from such regions, highlighting the incidence and nodal characteristics of malignant versus non-malignant 18 F-FDG-avid mediastinal lymphadenopathy utilizing EBUS-TBNA, thus restricting the understanding concerning the risk stratification of lymph nodes for malignancy based on PET-CT.…”