Pulmonary Kaposi's Sarcoma: Diagnostic Features and Natural History in Patients with Acquired Immuneodeficiency Syndrome

Abstract

OBJECTIVE: This retrospective descriptive study was undertaken to highlight the diagnostic features and natural history of pulmonary Kaposi's sarcoma (KS).METHODS: Thirty-three patients with symptomatic pulmonary KS were assembled from a cohort of 239 patient with KS. Pulmonary KS was diagnosed by visualization of endobronchial lesions at bronchoscopy or based on clinical-radiological correlation and exclusion of opportunistic infections.RESULTS: The median time from initial presentation with KS to the development of pulmonary involvement was nine months. Dyspnea (79%) and dry cough (79%) were the most common presenting symptoms. Oral palatal involvement was present in 58% of patients with pulmonary KS. Pulmonary nodules (58%) were the most common radiological finding, but an interstitial pattern was noted in 42% of patients. Pleural effusion was present in 39%. Radiological patterns were not static, as 50% of patients with an initial interstitial pattern progressed to develop poorly formed nodules in the peripheral lung fields. Endobronchial lesions were noted on bronchoscopy in 23 patients. A presumptive diagnosis of pulmonary KS was made in 10 patients, with autopsy confirmation in four. Chemotherapy completely resolved symptoms in nine of 25 treated (36%) patients, and a further nine (36%) experienced a significant reduction in symptoms. Radiological improvement was noted in two of the clinical responders. Median survival from the time of diagnosis of pulmonary KS was only eight months, and symptoms relapsed within six weeks of achieving the best clinical response with chemotherapy.CONCLUSIONS: Pulmonary KS presents a difficult diagnostic challenge due to a nonspecific constellation of symptoms and radiological findings. Bronchoscopy is diagnostic when endobronchial lesions are visualized but, more important, it can exclude opportunistic infections. In some patients, even with a negative bronchoscopy, the diagnosis may still be established using clinical-radiographic correlation, particularly if there is radiological evolution to a nodular pattern over time. Multidrug chemotherapeutic regimens appear to have some symptomatic benefit, but radiological improvement is extremely limited. Progression of disease occurs in virtually all patients, and the median survival is only eight months from the point of recognition of pulmonary KS.