[Caplan's syndrome: rarely presenting as <> syndrome]. / Caplan-Syndrom: eine untypische Differenzialdiagnose des «pulmorenalen¼ Syndroms.

HISTORY AND ADMISSION FINDINGS: A 59-year-old man complained about having dry cough for months and a recent sudden onset of minor hemoptoe, asymmetric arthritis, myalgia as well as lack of appetite. He presented an occupational history of 12-year exposure to an organic dust as uranium miner in German Democratic Republic followed by 21 years as heavy construction worker in Germany and in Switzerland. Laboratory work-up tested positive for microhematuria and anti-neutrophilic cytoplasmic antibodies (ANCA). Chest X-rays and CT scan showed bilaterally scattered nodules. Thoracoscopic wedge resection was performed, histopathological analysis revealed granuloma with central necrotic area containing black coal dust and silica depositions surrounded by histiocytes. The pulmonary opacities on X-ray and the typical histology in the light of significant dust exposure allow the diagnosis of a Caplan's syndrome. TREATMENT AND COURSE: The symptoms improved rapidly under steroid therapy. Further investigations revealed a clear renal cell carcinoma as a cause for the persistent microhematuria. CONCLUSION: Rheumatoid arthritis, pulmonary nodules and history of prolonged dust exposure are classical findings that define Caplan's syndrome. These patients present with different immunological phenomena - in our case ANCA-positivity without vasculitis. Interestingly, the renal cell carcinoma which led to the "pulmorenal" syndrome in our patient is another health problem overrepresented in uranium mine workers.

[Rheumatoid arthritis and interstitial lung alterations - a clear case, isn't it?]. / Rheumatoide Arthritis und interstitielle Lungenver-änderungen - Ein klarer Fall! Oder eben doch nicht?

In a patient with rheumatoid arthritis (RA) and asymptomatic, diffuse reticulo-nodular lung parenchymal alterations with upper lobe predominance, a Caplan syndrome (CS) was diagnosed. According to the size of the pulmonary nodules, classification into two subtypes of the CS has been proposed: the classic (Caplan) type and the silicotic type. Patients with CS often present with considerable x-ray or computertomographic changes but relatively few symptoms. However, in case of respiratory symptoms, infectious complications or pneumotoxic side effects of the immunsuppressive/immune-modulating pharmacotherapy for RA must be encountered in the differential diagnosis.

Rheumatoid pneumoconiosis (Caplan's syndrome).

In 1953, Caplan described a characteristic radiographic pattern in coal miners with rheumatoid arthritis (RA) that was distinct from the typical progressive massive fibrosis pattern of coalworkers' pneumoconiosis. It consists of multiple well-defined rounded nodules on chest X-ray, from about 0.5 to about several centimetres in diameter, distributed throughout the lungs but predominantly at the lung periphery. Lesions appear often in crops, may coalesce and form a larger confluent nodule. Nodules often cavitate or calcify. They typically occur in the setting of pre-existing mild pneumoconiosis, but pneumoconiosis is not a prerequisite. The onset of the nodules is typically sudden, and their course varies thereafter, ranging from regression to progression. Histologically, the nodules have a characteristic appearance and are distinguishable from silicotic nodules or progressive massive fibrosis. Individual susceptibility is considered to play a role in the development of the disease. However, the pathogenetic link between exposure to silica, pneumoconiosis and RA has not been clarified conclusively. This review summarizes history, definition and current knowledge on epidemiology, pathology, pathophysiology, clinical presentation and treatment of Caplan's syndrome.

Rheumatoid pneumoconiosis (Caplan's syndrome) with a classical presentation.

Although rare, rheumatoid pneumoconiosis, also known as Caplan's syndrome, can occur in workers exposed to silica, as well as in patients with silicosis, coal workers' pneumoconiosis or asbestosis. Prevalence is higher among patients with silicosis, despite the fact that it was originally described in coal workers with pneumoconiosis. The classical finding that defines this syndrome is that of rheumatoid nodules in the lungs, regardless of whether there are small rounded opacities suggestive of pneumoconiosis or large opacities consistent with massive pulmonary fibrosis, with or without clinical rheumatoid arthritis. We describe the case of a female patient with rheumatoid arthritis, diagnosed 34 years after 7 years of occupational exposure to silica at a porcelain plant. A chest X-ray showed circular opacities of 1-5 cm in diameter, bilaterally distributed at the periphery of the lungs. A CT-guided thoracic punch biopsy of one of those nodules revealed that it was rheumatoid nodule surrounded by a palisade of macrophages, which is typical of Caplan's syndrome. Aspects of diagnosis, classification and occurrence of this syndrome are discussed, emphasizing the importance of the occupational anamnesis of patients with rheumatoid arthritis and lung opacities on chest X-rays.

Pneumoconiose reumatoide (síndrome de Caplan) com apresentação clássica / Rheumatoid pneumoconiosis (Caplan's syndrome) with a classical presentation

Apesar de rara, a pneumoconiose reumatoide, também chamada de síndrome de Caplan, pode ser diagnosticada entre trabalhadores expostos à sílica e entre pacientes com silicose, pneumoconiose dos mineiros de carvão e asbestose. A maior prevalência ocorre entre os silicóticos, apesar de ter sido descrita inicialmente em mineiros de carvão com pneumoconiose. O achado que define o tipo clássico da síndrome é a presença de nódulos reumatoides nos pulmões, independente da presença ou não de pequenas opacidades pneumoconióticas, ou de grandes opacidades de fibrose pulmonar maciça, associada ou não a um quadro de artrite reumatoide em atividade. Relatamos o caso de uma mulher com quadro de artrite reumatoide, diagnosticada 34 anos após exposição à sílica livre em uma indústria de porcelana por 7 anos, apresentando radiograma de tórax com opacidades arredondadas de 1 a 5 cm de diâmetro, distribuídas na periferia de ambos os pulmões. A biópsia transtorácica guiada por TC de um dos nódulos revelou tratar-se de nódulo reumatoide com macrófagos em paliçada, típico da síndrome de Caplan. São discutidos aspectos de diagnóstico da síndrome, classificação e ocorrência, ressaltando a importância da anamnese ocupacional em casos de artrite reumatoide com opacidades radiológicas pulmonares.

Although rare, rheumatoid pneumoconiosis, also known as Caplan's syndrome, can occur in workers exposed to silica, as well as in patients with silicosis, coal workers' pneumoconiosis or asbestosis. Prevalence is higher among patients with silicosis, despite the fact that it was originally described in coal workers with pneumoconiosis. The classical finding that defines this syndrome is that of rheumatoid nodules in the lungs, regardless of whether there are small rounded opacities suggestive of pneumoconiosis or large opacities consistent with massive pulmonary fibrosis, with or without clinical rheumatoid arthritis. We describe the case of a female patient with rheumatoid arthritis, diagnosed 34 years after 7 years of occupational exposure to silica at a porcelain plant. A chest X-ray showed circular opacities of 1-5 cm in diameter, bilaterally distributed at the periphery of the lungs. A CT-guided thoracic punch biopsy of one of those nodules revealed that it was rheumatoid nodule surrounded by a palisade of macrophages, which is typical of Caplan's syndrome. Aspects of diagnosis, classification and occurrence of this syndrome are discussed, emphasizing the importance of the occupational anamnesis of patients with rheumatoid arthritis and lung opacities on chest X-rays.

[New possibilities of making the diagnosis of Caplan syndrome]. / Nowe mozliwosci rozpoznawania zespolu Caplana.

We describe a 56-year old man with rheumatoid arthritis and pulmonary nodules detected by HRCT. Needle biopsy confirmed the diagnosis of Caplan syndrome.

Computed tomography findings of Caplan syndrome.

We report a case of Caplan syndrome complicated with tuberculosis, which was clinically followed up for 18 years and underwent autopsy. Initial chest radiograph showed 2 large nodules against the background of smaller pneumoconiotic nodules. One of the large nodules showed cavitation during follow-up. Computed tomography (CT) was helpful in identifying calcification in another large nodule. Autopsy confirmed the 2 large nodules as burned-out rheumatoid nodules and revealed additional rheumatoid nodules that were indistinguishable from silicotic nodules by CT.

[Biventricular inflow tract compression by chronic organized hemopericardium in Caplan syndrome]. / Biventrikuläre Einflusstraktkompression durch chronisch organisiertes Hämoperikard bei Caplan-Syndrom.

We report the case of a 59-year old patient with the rare combination of silicosis and rheumatoid arthritis, which is called Caplan's syndrome. The patient presented with right heart failure caused by a pericardial tumor compressing the right and the left ventricle. By means of several imaging techniques it was possible to elucidate the topographic relations of the tumor. Definite signs of malignant growth were not found. Despite his elevated perioperative risk we decided to operate on the patient. During the operation macroscopic and histologic evidence revealed that the tumor was not a neoplastic process but consisted of an organized hemopericardium. This demonstrates that pericarditis in rheumatoid arthritis can be hemorrhagic and can mimick a malignant pericardial tumor. The decision to operate was first supported by the findings of the applied imaging techniques, the normal endomyocardial biopsy, and the clinical course and were later confirmed in situ.

Changes of the lung in rheumatoid arthritis--rheumatoid pneumonia. A clinicopathological study.

The frequency and patho-histological characteristics of pulmonary changes were studied on the autopsy material of 100 patients with rheumatoid arthritis (RA). The formal pathogenesis and different stages of vasculitis, rheumatoid nodule, interstitial pneumonia, rheumatoid pleuritis, obliterative bronchiolitis, amyloidosis and the so-called rheumatoid pneumonia in the lungs is discussed. The rheumatoid pneumonia is a disseminating inflammatory lobular-sublobular process, not described previously. The frequency of rheumatoid pneumonia was 4%. The rheumatoid pneumonia is characterized by the necrotic vasculitis, fibrinoid necrosis or thrombovasculitis of the pulmonary and bronchial arterioles, and of small arteries. Because of the diminished blood supply distal to the vascular changes inflammatory foci may develop, more or less respecting the anatomic borders of pulmonary tissue. The lobular-sublobular inflammation is basically of non haemorrhagic character. Because of the recurrent nature of vasculitis, foci of inflammation in different stages can be observed in the lungs simultaneously side by side. Clinically the rheumatoid pneumonia was accompanied by severe RA, according to the frequency and severity of acute exacerbations. In all 4 cases of rheumatoid pneumonia the pulmonary process had been proven clinically and radiologically. Rheumatoid pneumonia occurred subsequent to recurrent arthritis following steroid withdrawal, and it was resistant to antibiotics.

Rheumatoid pneumoconiosis in a dolomite worker: a light and electron microscopic, and X-ray microanalytical study.

A 46-year-old woman suffering from rheumatoid arthritis developed numerous round opacities at the apex of the right lung 11 years after an exposure to dolomite . Resected lung showed discrete nodules, 0.8-2 cm in diameter, with central necrosis surrounded by palisading fibroblasts and a prominent inflammatory zone. A large number of birefringent dust particles were seen in the necrotic centres and around the nodules. By electron microscopy the particles were dense, mostly elongated and lamellar, varying from 0.005 to 3 microns in width, and from 0.1 to 6.5 microns in length. Energy dispersive x-ray microanalysis of the dust particles gave elemental spectra with high spikes of silicon, aluminium and potassium, and minimal magnesium, calcium, iron and titanium. According to chemical analysis, the original dolomite consisted almost entirely of magnesium and calcium carbonates and only of traces of silicon, aluminium and potassium. Apparently the human organism can better eliminate calcium and magnesium carbonates than silicon, aluminium and potassium.

Caplan's syndrome - a clinical study of 13 cases.

Thirteen cases of Caplan's syndrome were investigated by chest X-ray, rheumatic and immunological tests, heart and lung physiology and pathological-anatomical specimens. No positive correlation was found between exposure time to silica, roentgenolgical findings, degree of rheumatoid factor or physiological findings. In nine of the cases a rapid roentgenological progress took place. Although the combination of lung infiltrations and rheumatic disorders makes an immunological reaction probable, no correlation was found between the degree of rheumatic disorder and roentgenological progress. The hypothesis that silica acts as an adjuvant, which may strengthen an antigen-antibody reaction, was not reflected in rheumatic parameters. The roentgenological examination appeared to be the most sensitive method for following the disease.