Venous thrombosis is a frequent complication of malignancy; however, acute arterial occlusion secondary to malignant (non-myxomatous) tumor embolism is a rare event [7
]. Venous tumor emboli most often present with symptoms of pulmonary embolism and/or infarction [8
]. Arterial embolism results in organ ischemia/infarction, and must be recognized and managed appropriately [6
]. In most cases, a primary or metastatic pulmonary neoplasm gains access to the arterial system by invading the heart through the pulmonary veins [5
]. Fewer than ten cases of spontaneous tumor embolization resulting from lung cancer invasion of the pulmonary vein have been reported [5
]. The sites of tumor emboli reported most frequently are the aortic bifurcation or femoral vessels (50%), and the cerebral circulation (30%) [9
]. Patient symptoms are related to the embolic location, and most commonly include lower extremity, cerebral, myocardial, and limb ischemic events [10
]. To our knowledge, this is the first reported case of simultaneous non-myxomatous tumor embolization to the brain, spleen, kidneys and bilateral lower extremities.
Cerebral ischemia has several major etiologies, including atherosclerosis, cardiogenic emboli, vasculitis, increased blood viscosity and carotid dissection [11
]. About 80% of all cerebrovascular events are ischemic in origin, and most are associated with atherosclerotic disease [11
]. Cardiogenic emboli account for 15–30% of ischemic strokes [5
]. Embolic strokes are characteristically abrupt in onset.
Acute limb ischemia is typically categorized as thrombotic, embolic or traumatic [12
], and characteristically described by the six Ps: pain, pallor, pulselessness, paresthesias, poikilothermia and paralysis [13
]. Embolization of the peripheral artery is most commonly cardiogenic (80–90%), but emboli originating from a malignant tumor are rare [4
The vast majority (88%) of splenic infarctions are caused by either infiltrative hematologic diseases resulting in congestion of the splenic circulation by abnormal cells or thromboembolic conditions causing vessel obstruction [14
]. In a 10-year retrospective study, Antopolsky et al. examined clinical presentations in 49 episodes of acute splenic infarction. The most common symptom was either abdominal or left flank pain (80% of episodes), while the most common sign was upper left quadrant tenderness (35% of episodes) [15
There are two major causes of acute renal infarction: thromboemboli, usually originating from a thrombus in the left atrium or aorta, and less commonly, a thrombosis within a renal artery [16
]. Other rare potential embolic sources include valvular vegetations, tumor and fat emboli, and paradoxical embolism through a patent foramen ovale [17
]. Because patients present with abdominal or flank pain that mimics other conditions, such as nephrolithiasis and pyelonephritis, renal infarction is under-diagnosed and frequently missed [18
]. The patient described in our study presented simultaneously with an acute onset of intermittent aphasia suggestive of an acute cerebral embolic event, bilateral lower extremity pain and paresthesias suggestive of acute limb ischemia, and left flank pain suggestive of splenic and/or renal infarction.
Arteriography is the diagnostic procedure of choice for identifying an acute arterial occlusion. In addition to demonstrating detailed arterial anatomy, arteriography can usually distinguish between thrombosis and embolism [19
]. An embolus will often demonstrate a sharp cutoff with a rounded reverse meniscus sign. The embolus may also be visible as an intraluminal filling defect if the vessel is not completely occluded. Other findings that are most consistent with an embolus include the presence of otherwise normal vessels, the absence of collateral circulation and the presence of multiple filling defects. Arterial thrombosis is usually visualized as a sharp or tapered, but not rounded cutoff on arteriography. Diffuse atherosclerosis with well-developed collateral circulation is generally present [20
Once an embolism has been identified, an embolectomy should be emergently performed, and anticoagulation and vasodilators started [7
]. In our case, the patient also required bilateral fasciotomies to treat revascularization compartment syndrome.