Pulmonary Kaposi's sarcoma: Premortem histologic diagnosis

Nine open lung biopsies and nine transbronchial biopsies from 10 patients with pulmonary Kaposi's sarcoma were reviewed to define the pattern of involvement in the lung by Kaposi's sarcoma and to determine the usefulness of transbronchial biopsy in making the diagnosis. There were nine patients with acquired immune deficiency syndrome (AIDS) and one patient with sporadic pulmonary Kaposi's sarcoma. A lymphatic distribution was seen in all cases. A spectrum ranging from distinctive polymorphous cellular infiltrates ultimately interpreted as Kaposi's sarcoma to 'classic' Kaposi's sarcoma was found. Recognition of the former enabled retrospective recognition of Kaposi's sarcoma in four of eight transbronchial biopsies. The diagnosis of pulmonary Kaposi's sarcoma in one other patient was made solely on the basis of transbronchial biopsy. Eight patients died from pulmonary Kaposi's sarcoma; two patients are alive with extensive pulmonary Kaposi's sarcoma at last follow-up. We believe that transbronchial biopsy may be useful in establishing a diagnosis of pulmonary Kaposi's sarcoma in many more patients than is generally appreciated.