Acute respiratory failure developing in a patient with lymphomatoid granulomatosis.

Lymphomatoid granulomatosis (LYG) is a rare B cell lymphoproliferative disorder associated with Epstein-Barr virus infection. LYG diagnosis is often difficult because of non-specific and varied radiological and pathological findings. The lung is the most common organ of LYG occurrence, but extrapulmonary lesions involving the central nervous system, skin, kidneys and liver are observed. A surgical biopsy is often inevitable for LYG diagnosis.We encountered a man in his 50s who presented with progressive dyspnoea. Extrapulmonary lesions were not observed. Although he developed respiratory failure within a short period, a low dose of corticosteroid relieved his symptoms. Video-assisted thoracoscopic lung biopsy revealed grade 1 LYG. The patient was successfully treated with chemotherapy, including rituximab. Only a few cases of LYG with progressive respiratory failure are reported, and most have been diagnosed via autopsy. Our case highlights the importance of performing a surgical lung biopsy at the appropriate time to diagnose LYG.