SESSION TITLE: Imaging Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: AIDS-related Kaposi Sarcoma (KS) is a vascular tumor associated with human herpesvirus 8. Pulmonary involvement is common, but rarely occurs in the absence of mucocutaneous lesions. Diagnosis may be confounded by the presence of opportunistic infections. We present a case of pulmonary KS without evidence of mucocutaneous or endobronchial involvement and discuss alternative diagnostic techniques.
CASE PRESENTATION: A 28 year-old man with AIDS presented with dyspnea on exertion and a chronic non-productive cough. He was diagnosed with HIV 10 years prior to admission, but had been off HAART for 2 years. Review of systems was notable for headache, diarrhea, chills, night sweats, and 10lbs weight loss. He was non-toxic appearing, afebrile and saturating 100% on room air. Exam was notable for thrush, poor dentition, tender submandibular lymphadenopathy, and fine inspiratory rales. Skin lesions were notably absent. Initial labs were remarkable for CD4 count of 3, HIV viral load 3x10^6, WBC 1.0, Hgb 10, normal LDH. Chest xray showed evidence of old granulomatous infection, but no acute findings. CT chest revealed ill-defined hematogenous appearing micronodules associated with ground glass opacities suspicious for pulmonary syphilis vs. lymphoma vs. KS. CT abdomen/pelvis showed scattered retroperitoneal lymphadenopathy. A bronchoscopy showed no abnormal lesions in either right or left tracheobronchial trees. BAL and infectious workup including PCP, fungal, and bacterial cultures were unremarkable. Nonetheles, high suspicion for KS prompted a thallium/gallium nuclear study. Pulmonary uptake was positive for thallium, but not gallium; a finding specific for KS. KS was later confirmed on HHV-8 positive submandibular node biopsy.
DISCUSSION: Pulmonary KS without mucocutaneous involvement represents fewer than 15% of pulmonary KS cases  and is more unusual in de novo cases. While bronchoscopy remains the most sensitive technique for diagnosis of pulmonary KS, lesions may not be detected if 1) KS does not involve bronchi or adjacent tissue 2) KS does not extend to submucosal tissue 3) interstitial involvement is microscopic 4) the bronchoscope is not advanced far enough to see distal disease . In such circustances, thallium/gallium uptake scan can distinguish KS from lymphoma and opportunistic infection. Thallium uptake is positive in lyphoma and KS and negative in infection. Gallium uptake is positive in lymphoma and infection, but negative in KS.
CONCLUSIONS: This case illustrates an atypical presentation of KS and highlights the utility of nuclear studies in assisting histopathologic confirmation of diagnosis with a high clinical index of suspicion.
Reference #1: 1. Huang L et al. Presentation of AIDS-related pulmonary Kaposi’s sarcoma diagnosed by bronchoscopy. Am J RespirCrit Care Med. 1996 Apr; 153:1385-90
Reference #2: 2. Driscoll, Barbara. Lung Cancer: Volume 2, Diagnostic and Therapeutic Methods and reviews. Springer Science and Business Media. 2002.
DISCLOSURE: The following authors have nothing to disclose: Caleb Hsieh, Nader Kamangar
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