1. Pulmonary involvement in HIV- associated Kaposi's sarcoma 基隆長庚醫院呼吸胸腔內科 姜伯穎 醫師 26 October, 2007

2. Kaposi's sarcoma (KS) the most common malignancy associated with HIV infection occurs in approximately 6 to 20 percent of HIV-infected homosexual or bisexual men and a small number of HIV- infected patients from other risk groups Kaposi's sarcoma-associated herpesvirus or human herpesvirus 8, is responsible for the development of Kaposi's sarcoma With prevention and control of opportunistic infections, patients with AIDS live longer, and disseminated malignancy has become one of the major causes of morbidity and mortality.

3. Clinical Presentation of KS Clinical Presentation of KS varies from indolent skin lesions to extensive visceral disease The face and mucous membranes of the oral cavity are common sites of initial involvement. Major clinical problems encountered with KS are –local disfigurement, –disabling lymphedema, and –extensive visceral involvement, with the gastrointestinal tract and lungs being the most common sites of disease

4. Pulmonary KS Approximately one-third of KS patients will have clinically evident pulmonary disease and one-half have pulmonary involvement at autopsy. Affected patients can present with shortness of breath, fever, cough, hemoptysis, or chest pain, or with no symptoms but an abnormal chest radiograph. In patients with known KS who present with a respiratory problem, up to 50 percent are due to parenchymal involvement by KS. KS can involve the lung parenchyma, the airways, the pleura, and intrathoracic lymph nodes.

5. Pulmonary KS – 1 Parenchyma –KS involves the lung typically in either an interstitial or nodular pattern. –Parenchymal involvement is usually manifested clinically by dyspnea, hypoxemia, and dry cough. Hemoptysis, fever, and occasionally respiratory failure can also occur. Endobronchial lesions –Violaceous or bright red lesions are found in some patients on the mucosa of the lower airways, especially at branching points, or, much less commonly, in the upper airways. –These lesions usually cause no symptoms, although intractable cough, hemoptysis, wheezing, upper airway obstruction, and atelectasis are occasionally seen.

6. Pulmonary KS – 2 Pleura –Pleural effusions are radiographically visualized in up to two thirds of patients with parenchymal KS and occasionally as an isolated phenomenon. –The effusion may be unilateral or bilateral and range from small to large. They are typically clear or serosanguineous and are almost always exudates. –Transudates and chylous effusions are rare. –Many effusions are asymptomatic. –However, chest pain can occur and, when the effusions are large, respiratory distress can be a serious problem. Intrathoracic adenopathy –Enlarged mediastinal nodes have been reported in up to 46 percent of cases, although the origin of the nodes is seldom documented in these reports. –The clinical significance of adenopathy in KS is related to the need to distinguish KS from other diseases which can cause adenopathy, such as infection.

7. Chest Radiographic Features of Pulmonary KS VariablesFeatures ParenchymaReticulonodular infiltrates due to tumor nodules. Diffuse interstitial infiltrates or linear/septal angiomatous infiltration. Focal air space consolidation or collapse. Parenchymal lesions may appear normal, particularly in the early stages of disease. PleuraPleural effusions on one or both sides of the chest that may vary considerably in size. LymphadenopathyIn advanced pulmonary KS, 10–20% of patients have enlarged hilar or mediastinal nodes. Radiol Clin North Am 1997; 35:1029–1082 Br J Hosp Med 1995; 53:344–350

8. Prognosis The median survival in HIV-infected patients with extensive pulmonary KS has been reported to be two to ten months In a retrospective review of patients treated with chemotherapy for extensive pulmonary KS, survival for responders was 10 months versus six months for nonresponders –Poor prognostic factors included: Presence of a pleural effusion Severe shortness of breath CD4 count below 100 Median survival in another study of 30 patients with symptomatic pulmonary disease treated with chemotherapy was 6.5 months. –Poor prognostic factors in this study were: Absence of cutaneous KS Presence of previous opportunistic infection CD4 count below 100 Hemoglobin below 10 g/dL Lack of radiographic response to chemotherapy Am J Med 1989 Jul;87(1):57-61 Thorax 1994 Oct;49(10):958-60

9. Treatment Treatment is palliative in almost all cases. Although biological modifiers such as interferon alfa have a role early or late in the course of KS, pulmonary involvement usually requires chemotherapy. Chemotherapy –KS responds to a variety of chemotherapeutic agents, including vincristine, vinblastine, bleomycin, doxorubicin, and paclitaxel. –Highly active antiretroviral therapy (HAART) is associated with both a decreased proportion of new AIDS cases with KS and a regression in size of existing KS lesions. Radiation therapy –Radiation therapy has been successfully used to treat symptomatic airway obstruction in KS. –There is often significant improvement in dyspnea and hemoptysis but survival is short, averaging 2.5 months in one series. Management of pleural effusions –Sclerosis is usually tried if the effusions recur after thoracentesis, but it is often ineffective. –Thus, repeated thoracentesis is the modality most often used to relieve symptoms, frequently in combination with chemotherapy in an attempt to control the disease.