Introduction

Pulmonary manifestations of rheumatoid arthritis (RA) are infrequent and they include: involvement of the small airway and the pleura, pulmonary rheumatoid nodules, drug-induced lesions, interstitial lung disease and tumors.

Pulmonary rheumatoid nodules are oligosymptomatic, although they can produce upper respiratory symptoms and hemoptysis. Their radiological characteristics, serum markers and histopathology allow us to differentiate them from diagnosis such as infections, neoplasms or drug toxicity.

We present the case of a woman with a diagnosis of RA from the National University Hospital of Bogota, Colombia, in whom cavitating pulmonary nodules were documented.

Case description

A 65-year-old woman with 6 days of cough, hemoptoic expectoration and left pleuritic pain, without fever or dyspnea. History of RA for 15 years under treatment with methotrexate (MTX)-leflunomide, and former heavy smoker.

On admission, the patient had left chest pain and tachycardia. Auscultation with decreased breath sounds and fine crackles in the left hemithorax; bilateral ulnar deviation, swollen joints: 9, painful: 2, assessment of disease activity by CDAI: 14. Normal blood tests with hemogram and renal function, CRP: 24.8 mg/dl, ESR: 48 mm/h and rheumatoid factor: 40.7IU/ml(0-14IU/ml).

Antibiotic therapy with piperacillin/tazobactam plus clarithromycin was started. Due to suspicion of pulmonary thromboembolism (PTE), it was performed an angiotomography, observing multiple nodules of soft tissue density, poorly defined, of 16-30 mm, subpleural and cavitary; cavitary mass in the apicoposterior segment of the left upper lobe of 37 mm in diameter, with bilateral basal interstitial involvement (Fig. 1), negative for PTE.

Fig. 1 Pulmonary nodules and interstitial lung involvement. (A) PA chest X-ray with cavitations in the left upper lobe and the right lower lobe. (B) Cavitary mass in the left upper lobe. (C) Cavitating nodule in the right lower lobe. (D) Left pleural effusion of free appearance. 

The following differential diagnoses were proposed: septic embolism, tuberculosis, fungal infection, rheumatoid lung, and MTX-leflunomide toxicity.

Considering the risk of worsening the lung compromise with MTX and leflunomide, treatment with chloroquine 250mg/day and sulfasalazine was started and the antibiotic was discontinued; a fibrobronchoscopy with bronchoalveolar lavage showed 60% of polymorphonuclear cells without malignancy. The transbronchial biopsy evidenced an abundant polymorphonuclear inflammatory component without malignancy or granulomas. Negative PCR for tuberculosis. The patient presented improvement, reduction of joint pain and swelling, and was discharged after 7 days.

Discussion

Pulmonary rheumatoid nodules are an uncommon extra-articular manifestation of RA. They predominate in men with a 7:1 ratio and appear late in the course of the disease.¹

The risk factors include: male gender, age, smoking, HLA-DRB1, severe erosive arthritis, subcutaneous nodules and high titers of rheumatoid factor. Their prevalence varies according to the study: by chest X-ray 1%, by HRCT 20-22% and by biopsy 32%.²

They are oligosymptomatic, although they can occur with cough and hemoptysis. The latency period ranges between 6 months and 11 years. Imagenologically they are bilateral, peripheral and subpleural, they measure up to 7 cm and 30% become cavitated. They can become calcified and be associated with pneumoconiosis, a condition called Caplan's syndrome.²

Differential diagnoses include:

The diagnosis relies on the clinical presentation, radiology, serum markers, biopsy that rules out neoplasm or infection and absence of temporal relationship with the use of drugs associated with nodulosis (DMARDs and anti-TNF).⁶

Histopathologically, they show central necrosis surrounded by lymphocytes, plasma cells, polymorphonuclear cells and perivascular granulation tissue. They are T helper-1 lymphocytes-mediated granulomas. An extensive polymorphonuclear component was found in our case in contrast with the classical histological description.

The complications include hemoptysis, bronchopleural fistula, pneumothorax and abscesses.²

There is no specific treatment and most of them remit spontaneously, without any relation to the evolution of the arthritis.⁶ In symptomatic cases requiring treatment, rituximab⁷ and tocilizumab⁸ have shown to be useful.

The prognosis is worse in patients with RA and pulmonary rheumatoid nodules.

Conclusion

Pulmonary rheumatoid nodules are uncommon and have a poor prognosis because they are associated with severe joint commitment and greater mortality.

Their most serious complications are hemoptysis, bronchopleural fistula and pneumothorax. They should be considered in the differential diagnosis of nodules due to pulmonary tuberculosis and neoplasms; that is why their diagnosis is based on the clinical presentation and the histopathological study, after excluding other potentially serious causes. In the great majority of cases they do not require treatment.