(150) Cardiac Sarcoidosis and the Diagnostic Value of Excisional Lymph Node Biopsy

Introduction: Sarcoidosis is a chronic condition of unknown etiology with multi-organ involvement consisting of granulomatous inflammation leading to fibrosis and end-organ dysfunction. Cardiac fibrosis is emerging in about 5-10% of sarcoidosis cases and is increasingly becoming diagnosed.

Description: 39-year-old male patient initially presented to the ED with 3 days of progressive shortness of breath, cough and chest pain with known influenza exposure. He had a past medical history of pulmonary hypertension (PH), congestive heart failure and polysubstance abuse. In the ED, his labs revealed hyponatremia and elevated, up-trending troponin, however, EKG was unchanged. He tested positive for Influenza A and CT chest showed bilateral interstitial opacities concerning for pneumonia. He was treated with ceftriaxone, azithromycin, tamiflu, aspirin and started on heparin for elevated troponins and possible ACS. His echo showed EF 56%, dilated RV with reduced systolic function and elevated pressure and severe PH. He was initially placed on CPAP. Due to worsening respiratory status, escalated to BiPAP and transferred to the ICU for acute hypoxic respiratory failure (AHRF) where he was urgently intubated. Cardiac MRI was performed and was concerning for cardiac sarcoidosis, being suspicious as the cause of AHRF and PH. Endobronchial ultrasound (EBUS) was performed twice and was negative for metastasis or sarcoidosis repeatedly. An excisional lymph node biopsy was performed which confirmed sarcoidosis. Prednisone was started which resulted in good response and he was successfully extubated. The patient’s respiratory status continued to improve, and he was able to be discharged.

Discussion: New diagnostic modalities such as cardiac MRI and PET scan contribute to increasing clinical awareness of cardiac sarcoidosis. Despite this progress, it can be difficult to differentiate from other causes of cardiomyopathy. The difficulty in diagnosis in this case was attributed to the repeatedly negative EBUS findings due to inadequate tissue sampling. Therefore, in cases where suspicion for sarcoidosis remains high despite negative EBUS results, excisional lymph node biopsy can help confirm the diagnosis as it provides a greater tissue sample to visualize non-caseating granulomas which could otherwise be missed.