Rheumatoid Lung Nodules

Fig. 23.2 Cavitary lung nodules representing pulmonary metastatic nodules in a 50-year-old man with renal cell carcinoma. (a, b) Lung window images of CT scans (5.0-mm section thickness) obtained at levels of right upper lobar bronchus (a) and basal trunks (b), respectively, show multiple cavitating (arrows) and noncavitating nodules in both lungs. (c)

Enhanced CT scan obtained at level of cardiac ventricle shows a lowattenuation nodule (arrow) in right ventricle abutting lateral wall of the chamber. (d) Fluorodeoxyglucose positron emission tomography displays high uptake of glucose (arrow) at right ventricular nodule. Arrows in (c) and (d) indicate metastatic nodules in right cardiac ventricle

Rheumatoid Lung Nodules

Pathology and Pathogenesis

The rheumatoid lung nodules have a necrotic center of finely granular eosinophilic debris surrounded by a capsule of chronic inflammatory granulation tissue. The boundary between dead and viable tissue is marked by a characteristic palisade of radially oriented macrophages (Fig. 23.1). The inflammatory cells include a small number of giant cells as well as plentiful lymphocytes and plasma cells [8].

Symptoms and Signs

Most patients with rheumatoid lung nodules are asymptomatic. Occasionally, cavitation may lead to hemoptysis [9].

Due to their typical subpleural distribution, complications, including pneumothorax, empyema, pleural effusions, and bronchopleural fistula, may occur.

CT Findings

Rheumatoid nodules have a maximum diameter of 0.5– 5.0 cm and are usually located in peripheral zones of the upper and middle lung regions [10] (Fig. 23.1). Pulmonary nodules may increase in size or resolve spontaneously. Cavitation of nodules is common and is rarely associated with rupturing into the pleural space, producing bronchopleural fistula, pneumothorax, pleural effusion, or empyema [11]. Calcification of rheumatoid pulmonary nodules is not a frequent finding but may be seen in some patients with Caplan syndrome.