An Algorithm for Approaching Mediastinal Lymphadenopathy in Pulmonary Hypertension: Response

Abstract

We are grateful for the thoughtful commentary by Dr Medford relating to our recent article in CHEST.1Moua T Levin DL Carmona EM Ryu JH Frequency of mediastinal lymphadenopathy in patients with idiopathic pulmonary arterial hypertension.Chest. 2013; 143: 344-348Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar We agree that because procedural risk in patients with idiopathic pulmonary arterial hypertension (IPAH) is high, pretest suspicion for a more ominous diagnosis is warranted prior to invasive studies of associated mediastinal lymphadenopathy (MLAD). Specifically, exclusion of malignancy (lymphoma, lung primary, metastatic primary, and so forth) should be the only immediate justification for invasive assessment in this setting. Unfortunately, few studies have commented on MLAD associated with pulmonary hypertension. Our observed frequency of close to one in five patients with IPAH (18%) involved a selected cohort with both right-sided heart catheterization and chest CT scan for the purposes of correlating lymphadenopathy with severity of cardiac hemodynamics. This may underestimate the true prevalence of MLAD in all patients with IPAH. We did find a similar distribution and size of abnormal lymph nodes when compared with left-sided congestive adenopathy,2Ngom A Dumont P Diot P Lemarié E Benign mediastinal lymphadenopathy in congestive heart failure.Chest. 2001; 119: 653-656Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar and, although others have shown resolution or improvement in adenopathy following heart failure treatment,3Chabbert V Canevet G Baixas C et al.Mediastinal lymphadenopathy in congestive heart failure: a sequential CT evaluation with clinical and echocardiographic correlations.Eur Radiol. 2004; 14: 881-889Crossref PubMed Scopus (28) Google Scholar only one of nine patients with MLAD and follow-up CT scanning in our study had regression, despite receiving therapy. These specific findings from our study contribute to the clinical understanding of MLAD associated with pulmonary hypertension and may be applicable to MLAD with pulmonary hypertension from other causes. As Dr Medford noted, enlarged nodes of <2 cm on short axis with known left- or right-sided heart disease may justify observation with directed heart failure management for 1 to 3 months prior to invasive assessment. This approach appears reasonable for MLAD and pulmonary hypertension from most causes. For example, pulmonary hypertension associated with sarcoidosis may be a unifying diagnosis in some patients presenting with persistent MLAD.4Handa T Nagai S Miki S et al.Incidence of pulmonary hypertension and its clinical relevance in patients with sarcoidosis.Chest. 2006; 129: 1246-1252Abstract Full Text Full Text PDF PubMed Scopus (213) Google Scholar PET scanning and other studies may be suggestive in this setting,5Prabhakar HB Rabinowitz CB Gibbons FK O'Donnell WJ Shepard JA Aquino SL Imaging features of sarcoidosis on MDCT, FDG PET, and PET/CT.AJR Am J Roentgenol. 2008; 190: S1-S6Crossref PubMed Scopus (85) Google Scholar although sarcoidosis without pulmonary parenchymal findings is unlikely to be immediately life threatening, again justifying a period of observation prior to biopsy assessment if not regressing. There is a known frequent association of MLAD with interstitial lung disease,6Souza CA Müller NL Lee KS Johkoh T Mitsuhiro H Chong S Idiopathic interstitial pneumonias: prevalence of mediastinal lymph node enlargement in 206 patients.AJR Am J Roentgenol. 2006; 186: 995-999Crossref PubMed Scopus (76) Google Scholar and, as such, diagnostic assessment without other clinical features of malignancy is likely unjustified. We suggest and agree with a cautious approach to MLAD associated with pulmonary hypertension of any cause, particularly if pretest suspicion for malignancy is low. Further prospective and observational work to refine a safe approach to MLAD in this setting is needed, as noted by Dr Medford. An Algorithm for Approaching Mediastinal Lymphadenopathy in Pulmonary HypertensionCHESTVol. 144Issue 1PreviewThe recently published article by Moua et al1 (February 2013) is timely but raises more questions about how to study patients with mediastinal lymphadenopathy (MLAD) and idiopathic pulmonary arterial hypertension (IPAH). It would be particularly helpful for clinicians who treat such patients to be able to perform a risk assessment of the need for mediastinal sampling in a patient group where even minimally invasive endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) or conventional TBNA2 is likely to be tolerated less well compared with patients without IPAH. Full-Text PDF