Sjögren's syndrome and fibrosing alveolitis complicated by pulmonary lymphoma

Imaging manifestations of autoimmune disease-associated lymphoproliferative disorders of the lung

Lymphoproliferative disorders (LPDs) may involve intrathoracic organs in patients with autoimmune disease, but little is known about the radiologic manifestations of autoimmune disease-associated LPDs (ALPDs) of the lungs. The purpose of our work was to identify the radiologic characteristics of pulmonary involvement in ALPDs. A comprehensive search for PubMed database was conducted with the combination of MeSH words. All articles which had original images or description on radiologic findings were included in this analysis. Also, CT images of eight patients with biopsy-proven lymphoproliferative disorder observed from our institution were added. Overall, 44 cases of ALPD were identified, and consisted of 24 cases of bronchus-associated lymphoid tissue lymphoma (BALToma), eight cases of non-Hodgkin's lymphoma (NHL), six cases of lymphoid interstitial pneumonia (LIP), two cases of nodular lymphoid hyperplasia, two cases of unclassified lymphoproliferative disorder, and one case each of lymphomatoid granulomatosis and hyperblastic BALT. Multiple nodules (n = 14, 32 %) and single mass (n = 8, 18 %) were the predominant radiologic manifestations. The imaging findings conformed to previously described findings of BALToma, NHL, or LIP. Data suggest that BALToma, NHL, and LIP are the predominant ALPDs of the lung, and ALPD generally shared common radiologic features with sporadic LPDs. Familiarity with ALPDs and their imaging findings may enable radiologists or clinicians to include the disease as a potential differential diagnosis and thus, to prompt early biopsy followed by appropriate treatment.

Collagen Vascular Diseases and Disorders of Connective Tissue

The collagen vascular diseases, also referred to as connective tissue diseases, are a diverse group of systemic inflammatory disorders thought to be immunologically mediated. The concept of collagen vascular disease began to take shape in the 1930s, when it was recognized that rheumatic fever and rheumatoid arthritis can affect connective tissues throughout the body.1,2 During the following decade, as conditions such as systemic lupus erythematosus (SLE) and scleroderma came to be viewed as systemic diseases of connective tissue, the terms diffuse connective disease and diffuse collagen disease were proposed.3,4 During the same period, the designation of diffuse vascular disease was proposed for diseases such as scleroderma, polymyositis, SLE, and polyarteritis nodosa, which featured widespread vascular involvement.5 With the realization that many of these entities can exhibit both systemic connective tissue manifestations and vascular abnormalities, the unifying designation of collagen vascular disease was introduced.6

Primary Sjögren's syndrome

Significant abnormalities in pulmonary function are encountered in about 24% of patients with primary Sjögren's syndrome. The most common cause of dyspnoea is interstitial fibrosis, with a prevalence of around 8%, but a number of other pathologies may be encountered in the lungs of these patients (Table 1). Lymphoproliferative disorders are relatively uncommon, but these apparently benign lesions may harbour malignant potential. Interstitial fibrosis and the lymphoproliferative disorders may be responsive to corticosteroids or cytotoxic agents, and it is therefore important to establish an accurate diagnosis at an early stage. On the basis of our experience we would recommend the investigative strategy outlined below. Patients should be screened for significant lung disease by taking a careful history of respiratory symptoms followed by standard pulmonary function testing (including measurement of carbon monoxide diffusing capacity) and chest radiography. High resolution computed tomography is a non-invasive technique that should prove superior to chest radiography in the detection of early cases of interstitial fibrosis. When the disease is patchy it may be useful in identifying areas of maximal involvement for subsequent biopsy. Bronchoalveolar lavage is a sensitive tool in the non-smoker, but lacks the specificity to command a significant role in the investigation of pulmonary pathology in these patients. One exception to this may be in the investigation of the clonality of lymphocytes which may allow early and specific diagnosis of lymphomatous proliferation. The application of techniques such as the polymerase chain reaction may assist in the investigation of the role of the Epstein-Barr virus in the causation of lymphoproliferative lesions. In most patients with significant symptoms and abnormalities of pulmonary function a tissue diagnosis will be required, either by transbronchial biopsy or by open lung biopsy. Both bronchial and interstitial lung tissue should be obtained where possible. Histological confirmation is probably mandatory when there is a recent history of parotid enlargement, weight loss or the appearance of a monoclonal gammopathy. Advances in our understanding of the mechanisms of the MALT system may provide the key to unlocking some of the mysteries of 'autoimmune' diseases such as Sjögren's syndrome. The response of lymphoproliferative disorders to immunosuppressive therapy provides hope that if the diagnosis of sicca syndrome can be made earlier lymphocyte induced tissue damage may be halted or reversed.