SESSION TITLE: Lung Cancer Cases
SESSION TYPE: Affiliate Case Report Slide
PRESENTED ON: Sunday, October 25, 2015 at 10:45 AM - 12:00 PM
INTRODUCTION: Thrombotic pulmonary embolism and tumor emboli are in the differential of patients that present with filling defects in pulmonary arteries and history of cancer.
CASE PRESENTATION: 49M heavy smoker (>20 PPD), h/o HIV/AIDS (dx 2002) on ARTs, with locally advanced anal squamous cell carcinoma, stage IIIB, incompletely treated with cis/5-FU. Patient admitted with fever, enlarged right groin mass with mixed bacterial superinfection (E.coli, MSSA and Enterococcus faecalis) and weight loss. He denies dyspnea, cough, and hemoptysis. Physical examination remarkable for right inguinal friable exophitic fungating mass. After prolonged course of antibiotic therapy (1 month), re-screening for metastasis was done. PET scan showed hypermetabolic activity in right ulcerating mass, soft tissue anal mass and multiple hypermetabolic foci within the lungs varying from 8mm-1.5 cm with SUV 1.5-4.4, mimicking lung metastasis. Review of PET Scan and CT AP showed the FDG avid foci correspond to filling defects within multiple pulmonary arterial branches, compatible with tumor emboli.
DISCUSSION: Both pulmonary embolism and tumor emboli have filling defects of pulmonary arteries, and frequently FDG-PET scan is useful because tumor emboli are FDG avid, whereas thromboemboli are not, with cut-off point for SUVmax <3.51. Tumor emboli are defined as solid tumors within pulmonary arteries and arterioles (prevalence 3-26%) requiring high clinical suspicion (6% have correct diagnosis)2. The most frequent metastasis of anal carcinoma is liver, and rare or no described cases of tumor emboli, with the greatest risk appearing with mucin-secreting adenocarcinomas of breast, lung, stomach, and colon3.
CONCLUSIONS: The decision about how aggressively to pursue the diagnosis of pulmonary tumor embolism generally depends upon the nature of the underlying tumor. For patients with chemotherapy-resistant tumors, presumptive diagnosis is probably sufficient. In contrast, for patients with a chemotherapy-sensitive tumor or a suspected malignancy, more aggressive efforts to confirm the diagnosis are warranted.
Reference #1: Lee EJ, et al. Usefulness of fluorodeoxyglucose positron emission tomography in malignancy of pulmonary artery mimicking pulmonary embolism. ANZ J Surg. 2013;83(5):342-7.
Reference #2: Goldhaber SZ, et al. Clinical suspicion of autopsy-proven thrombotic and tumor pulmonary embolism in cancer patients. Am Heart J. 1987;114(6):1432-5.
Reference #3: Roberts KE, et al. Pulmonary tumor embolism: a review of the literature. Am J Med 2003;115:228-32.
DISCLOSURE: The following authors have nothing to disclose: Miguel Rondinel Robles, David Appel, Thomas Aldrich
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