Pulmonary Kaposi Sarcoma without Mucocutaneous Involvement: The Role of Sequential Thallium and Gallium Scintigraphy.

Kaposi sarcoma (KS) is a vascular-related tumor that has been associated with human immunodeficiency virus (HIV). It commonly involves the skin and lymph nodes, and infrequently involves the lungs. In very rare instances, pulmonary KS can be found in the absence of endobronchial and mucocutaneous involvement. Utilization of sequential thallium and gallium scintigraphy can aid in the diagnosis of pulmonary KS in the absence of mucocutaneous and endobronchial involvement. In this report, we discuss a case of a patient with acquired immunodeficiency syndrome who presented with dyspnea and cough and was found to have subtle pulmonary parenchymal nodular airspace opacities. He underwent negative infectious evaluation, including bronchoscopy. Despite the absence of mucocutaneous findings, sequential positive thallium and negative gallium scintigraphy led to an early diagnosis of pulmonary KS. Pulmonary KS in the absence of mucocutaneous involvement is a rare finding that is exceedingly difficult to diagnose. However, pulmonary KS should be considered in patients with HIV who present with respiratory symptoms even if the typical mucocutaneous manifestations of KS are absent. In such circumstances, sequential thallium and gallium scintigraphy can help differentiate pulmonary KS from other processes such as infections and lymphoma, and assist in establishing an earlier diagnosis.