Simultaneous occurrence of accelerated nodulosis in lungs, liver, and kidneys, and acute exacerbation of interstitial pneumonia in a patient with rheumatoid arthritis: an autopsy case report

Background Accelerated nodulosis (ARN) is a rare variant of rheumatoid nodules (RNs) that is characterized by a rapid onset or the worsening of RNs. It generally develops at the fingers in patients with rheumatoid arthritis (RA) receiving methotrexate (MTX). Few case reports have described ARN at an extracutaneous location. Case presentation An elderly patient with long-standing RA was admitted to our hospital with acute respiratory failure. Computed tomography upon admission showed diffuse ground-glass opacities superimposed with subpleural reticular shadowing and honeycombing and multiple nodules in the lungs and liver. Despite the discontinuation of MTX and introduction of an immunosuppressive regimen with pulse methylprednisolone followed by a tapering dose of prednisolone and intravenous cyclophosphamide, the patient died due to the acute exacerbation (AE) of RA-related interstitial lung disease (ILD) following the parallel waxing and waning of a diffuse interstitial shadow and pulmonary and liver nodules. At autopsy, RNs were scattered throughout both lung fields in addition to extensive interstitial changes. RNs were also detected in the liver and kidneys. The foci of cryptococcosis were mainly identified in alveolar spaces. Based on the clinical and pathological findings, these nodules were most consistent with ARN because of acute increases in the size and number of previously detected pulmonary nodules. Conclusion The present case is noteworthy because ARN was concurrently detected in multiple internal organs and may be associated with the AE of RA-related ILD.