[Pulmonary microvascular cytology in critical patients].

Cytology in blood drawn through a wedged Swan-Ganz catheter appears as a sensitive method for the diagnosis of carcinomatous lymphangitis in patients in whom transbronchial biopsy is considered dangerous or who refuse to undergo the latter procedure. However, its usefulness has not been assessed in critical patients with acute respiratory failure of unknown etiology in whom malignant disease is suspected. We report our experience in two patients admitted to the Intensive Care Unit with acute respiratory failure of unknown etiology: they were a female with breast carcinoma and a male with lymphoma in whom the cytological study of pulmonary capillary blood disclosed malignant cells. The clinical evaluation and the subsequent histological studies confirmed the pulmonary involvement by malignant disease in both cases.