RESUMO
Pleuro-pulmonary involvement is frequently encountered in connective tissue disease. The pathological changes due to connective tissue disease are multifold. They include pleural, interstitial and nodular manifestations as well as airway lesions and vascular changes. In clinical decision making it is important to differentiate between effects of the underlying connective tissue disease, complications due to treatment, such as opportunistic infections, toxic and idiosyncratic drug reactions, and unrelated primary pulmonary diseases. We describe 2 patients with a connective tissue disease and pleuro-pulmonary complications. The diagnostic procedures are discussed. The result of the open lung biopsy was consistent with the diagnosis of rheumatic disease and also Sjögren's disease in the first patient and excluded infection and vasculitis in the second patient. Whenever histological investigation is needed to establish and/or exclude a diagnosis of pulmonary involvement in connective tissue disease, the open lung biopsy remains the "gold standard". We therefore propose a flow-chart for use in the clinical approach to the patient with interstitial lung disease of unknown origin.