A Pragmatic Dilemma: A Case of Lung Adenocarcinoma Presenting as Upper and Lower Extremity Venous Thromboembolism and Protein C and S Deficiency.

SESSION TITLE: Pulmonary Vascular Disease Global Case ReportsSESSION TYPE: Global Case ReportPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Cancer continues to be one of the major causes of venous thromboembolism (VTE) worlwide, and as such, a global health burden. In the Philippines, the incidence of cancer with VTE is yet to be established, although malignancy itself is the third leading cause of morbidity and mortality. Among the malignancy types, that of the lung ranks first. And although rare, patients with lung cancer, especially the adenocarcinoma type, are at an increased risk of VTE.CASE PRESENTATION: A 63 year-old obese female was admitted due to a 3-day history of swelling of the left leg associated with upper back pain. She is a non-smoker. Of note however is a history of spontaneous abortion and intake of oral contraceptive pills. On examination, she had mid-thigh and calf asymmetry with pitting edema and localized tenderness from left foot to the middle 3rd of the left thigh. Venous doppler study of the left lower extremity showed totally occlusive acute to subacute deep venous thrombosis of the venous segments. In view of the upper back pain and chest xray finding of miliary-form nodules in both lungs, a computerized tomography (C.T.) of the chest with intravenous contrast confirmed left lower lobe, left paraaortic and right prevascular masses. CT scan guided biopsy of the left lower lobe mass was consistent with lung adenocarcinoma. CT Venogram of the neck revealed upper extremity vein thrombosis. Subsequent hypercoagulability study showed Protein C and S deficiency. In view of the these findings, adequate anticoagulation and palliative chemotherapy were initiated.DISCUSSION: Venous thromboembolism has an incidence 1-3 in 1000 per year. The patient's age, obesity, intake of OCPs and diagnosis of lung cancer were identified risk factors for VTE. Of these risk factors, cancer is the most important and well-established. J.W. Blom et al pointed out that patients with adenocarcinoma have a higher risk of developing venous thromboembolism as compared to patients with squamous cell carcinoma. This was attributed to the interaction of circulating carcinoma mucins with leukocyte L-selectin and platelet P-selectin without requiring accompanying thrombin generation thereby generating microthrombi. The development of another focal thrombus on the upper extremity points out to other possible risk factors other than lung malignancy. Glaring in the patient's profile is the history of spontaneous abortion, thus, a hypercoagulability workup was done and showed Protein C and S deficiency. However, the patient had a prior intake of warfarin and heparin which can give a false positive result. Repeat testing for protein C and S is recommeneded at least 3 to 6 weeks from the discontinuation of anticoagulant treatment (B. Lipe et al, 2011). But because of the potential risks of VTE and its lifethreathening sequelae, repeat testing was forgone.

CONCLUSIONS: Venous thromboembolism arising from two or more different areas warrants a thorough investigation in order to rule in and out an inherited or acquired cause. In this case, the dilemma exists between lung malignancy or thrombophilia as a cause of thrombosis. In either case, prudent and judicious treatment of the primary lung malignancy and adequate anticoagulant therapy could prevent future occurrence of thrombosis, and thus abating its potentially lifethreathening consequences.Reference #1: Blom JW, Osanto S, Rosendaal FR. The risk of a venous thrombotic event in lung cancer patients: higher risk for adenocarcinoma than squamous cell carcinoma. J Thromb Haemost 2004; 2: 1760-5Reference #2: S.M. Bates, R.Jaeschke, S.M.Stevens, S.Goodacre, P.S.Wells, M.D.Stevenson et al. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed. American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. CHEST 2012; 141(2)(Suppl):e351S-e418S.Reference #3: B. Lipe, D. Ornstein. Deficiencies of natural anticoagulants, Protein C, Protein S and Antithrombin. Circulation 2011; 124:e365-e368.DISCLOSURE: The following authors have nothing to disclose: Edgardo TiglaoNo Product/Research Disclosure Information.