静脉血栓栓塞性疾病是住院患者常见的并发症之一，具有发生率高、病死率高和住院费用增加等特点。本文报道1例67岁既往有真性红细胞增多症（PV）病史的男性，进食不当后出现腹胀、腹痛。增强CT显示小肠梗阻（SBO）、肠穿孔、阑尾炎和腹膜炎。经禁食、放置肠梗阻减压管、药物抗感染等非手术治疗后，肠梗阻症状改善且病灶局限化。但患者随后出现以左侧锁骨下静脉、颈内静脉和上肢静脉为主的血栓。笔者考虑肠梗阻导致的脓毒症和PV可能是静脉血栓形成的主要因素，给予普通肝素抗凝、羟基脲治疗PV。实验室化验血清抗心磷脂抗体、抗β2糖蛋白1抗体、狼疮抗凝物阳性。经积极的抗凝、糖皮质激素、羟氯喹和抗感染治疗，患者病情改善。出院后随访半年，患者大部分血栓消失。抗磷脂综合征（APS）和骨髓增生性肿瘤（MPN）均与血栓形成风险增加有关，但二者同时存在的报道并不多见。早期针对血栓的病因诊断及治疗对改善病程、预后至关重要。

Venous thromboembolic disease is one of the common complications of hospitalized patients and is associated with high morbidity, high mortality and increased hospitalization costs. We reported the case of a 67-year-old male patient with a history of polycythemia vera (PV), who presented with abdominal distension, abdominal pain after improper diet. A contrast-enhanced computed tomography scan showed small bowel obstruction, perforation, appendicitis, and peritonitis. He were given non-operative treatmentincluding fasting, decompression tube placement, and anti-infection. The symptoms of ileus improved and the lesion was localized, but thrombosis was found in the subclavian vein, internal jugular vein, and upper limb vein on the left. Both of the sepsis and PV were thought to contribute to thrombosis. Heparin was used for anticoagulation and hydroxyurea for PV. Further laboratory tests revealed that serum antiphospholipid antibodies, anti-β2-glycoprotein Ⅰ antibodies and lupus anticoagulant were positive. With a combination therapy of anticoagulation, steroid, hydroxychloroquine and antibiotic, the patient's condition rapidly improved. Most venous thrombosis disappeared at half a year outpatient follow-up. Antiphospholipid syndrome (APS) and myeloproliferative neoplasms (MPN) are both associated with increased risk of thrombosis, but co-existence of these two conditions is rarely reported. Early diagnosis and treatment of thrombotic etiology are crucial to improve the course and prognosis of thrombosis.