Tissue Sampling in Suspected Sarcoidosis: Can We Avoid Mediastinal Procedures?

To the Editor:

We read with interest the recent American Thoracic Society clinical practice guidelines (1) for the diagnosis and detection of sarcoidosis. We are grateful to the guideline group for producing an important evidence-based document to guide clinicians across the world.

We would like to comment on the recommendation about tissue sampling for patients with suspected sarcoidosis on the basis of mediastinal and/or hilar lymphadenopathy, which forms Question 2 of the document: Should Patients with Suspected Sarcoidosis and Mediastinal and/or Hilar Lymphadenopathy, for Whom It Has Been Determined That Tissue Sampling Is Necessary, Undergo EBUS-guided Lymph Node Sampling or Mediastinoscopy as the Initial Mediastinal and/or Hilar Lymph Node Sampling Procedure?

The committee has recommended endobronchial ultrasound (EBUS)-guided lymph node sampling—rather than mediastinoscopy—as the initial procedure of choice to use the relatively less invasive of the two procedures. However, we believe that there is scope for an even lesser invasive approach in the scenario addressed in Question 2, applicable to a significant fraction of patients.

We have recently evaluated our experience (2) of performing ultrasound-guided core-needle biopsy of cervical lymph nodes in 25 patients suspected of sarcoidosis who had mediastinal and/or hilar lymphadenopathy on thoracic computed tomographic scans. It is important to note that the lymph nodes sampled following ultrasound were not generally enlarged, many with a short axis dimension <10 mm, and that in many cases, the lymph nodes were sonographically normal. Where a neck node could be biopsied, granulomatous inflammation was nearly always confirmed.

This technique is considerably cheaper than either EBUS–transbronchial needle aspiration or mediastinoscopy and less invasive than either. We therefore would strongly recommend that neck ultrasound be considered a first-line tool when pulmonologists are confronted with a patient with lymphadenopathy and tissue sampling is considered necessary to confirm granulomatous inflammation.

Moreover, the approach may have value (on a case-by-case basis) in the scenario posed in Question 1: Should Lymph Node Sampling Be Performed in a Patient Presenting with Asymptomatic Bilateral Hilar Lymphadenopathy? As these patients may be reluctant to undergo mediastinal procedures because of invasiveness and risk of complications, ultrasound assessment with a view to cervical lymph node sampling would be more acceptable.

We would recommend that pulmonologists and radiologists be more widely aware of the advantages of this approach and feel that dissemination of this option as an initial diagnostic modality could benefit a large number of patients and offer cost savings.

Finally, and importantly, it provides an attractive option during the current coronavirus disease (COVID-19) pandemic as a diagnostic modality with a lower crossinfection risk.