Foamy Macrophage Deposition in Lymph Nodes Mimicking Lung Cancer Recurrence Diagnosed via Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration.

The radiological finding of mediastinal lymph node enlargement following surgery for lung cancer often signifies locoregional recurrence. The use of oxidised cellulose haemostatic agents (OCHAs) during staging mediastinoscopy is common. We report a case of 18-fluorodeoxyglucose-avid subcarinal lymphadenopathy in a patient in whom OCHAs had been used at mediastinoscopy 5 months earlier. Histopathological examination of suspected nodal recurrence is facilitated by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The technique is particularly useful after previous mediastinoscopy, when repeat surgical exploration can be challenging. EBUS-TBNA samples showed extensive foamy macrophage deposition, with no evidence of malignancy. The association between the use of OCHAs and subsequent intranodal foamy macrophage deposition is new. Clinicians should consider this possibility in the differential diagnosis of mediastinal lymphadenopathy after surgical exploration, where OCHAs have been left in situ; it remains important to resample the lymph nodes before assuming disease recurrence to prevent unnecessary treatment.