A 24-year-old female with a history of ovarian cancer 4 years ago, s/p salpingo-oophorectomy and chemotherapy presents with acute onset of shortness of breath x 1 day. She denied any fevers, chest pain, or hemoptysis.
On exam, she was afebrile, normotensive but tachycardic to 125, tachypneic to 20, and hypoxic to 91% on RA. She was in mild respiratory distress, but the cardiopulmonary exam was otherwise unremarkable. Labs showed new thrombocytopenia of 43,000/uL, with schistocytes on the peripheral smear. The creatinine was 1.3 mg/dL, bilirubin 2.3 mg/dL, LDH of 541, haptoglobin of <20, d-dimer of 2130, and INR of 1.30. CT angiogram of the chest showed a small spiculated nodule, but no pulmonary embolism.
The presumed diagnosis was thrombotic thrombocytopenia purpura and a femoral shiley was placed for plasmapheresis. After placement, the patient had a PEA arrest. She had ROSC after 3 minutes of CPR. Bedside TTE in the MICU showed a severely enlarged hypokinetic RV with septal compression, consistent with acute cor pulmonale. Shortly thereafter, she coded again and passed away after 30 minutes of CPR. Autopsy showed cardiomegaly, pulmonary hypertension, and lymphatic metastases and thromboembolic disease in the lung related to ovarian cancer.
Tumor emboli syndrome is characterized by the presence of tumor cells in the small arteries and arterioles of the lung. Case studies show the majority of patients with tumor emboli syndrome on autopsy have lung, liver, breast, gastric, or ovarian cancer. Cancer cells lodge within the small vessels of the lung and induce fibrocellular proliferation and localized clotting due to cytokine release. This ultimately increases vascular resistance and causes pulmonary hypertension. These malignant cells may also produce VEGF and PDGF, worsening the vascular resistance. Lab findings are consistent with microangiopathic hemolytic anemia, and are related to the shearing forces associated with widespread tumor emboli.
CT scan cannot make the diagnosis, as it is not sensitive for these small tumor emboli. V/Q scan may show multiple matching defects. A PET scan may show multiple areas of uptake by malignant cells. Treatment of the syndrome consists of chemotherapy to target the underlying malignancy, along with supportive care for the pulmonary hypertension, including inotropic support, inhaled nitric oxide, diuresis, endothelin receptor antagonists, and PDE inhibitors. Case reports support the use of Imatinib to target PDGF. Despite this, the mortality is high given the acuity of and late presentation of these patients.
Diagnosis of tumor emboli syndrome requires a high suspicion in patients with a history of malignancy presenting with dyspnea. It is difficult to distinguish from pulmonary embolism, and has signs of microangiopathic hemolytic anemia, making TTP seem like a plausible diagnosis. Treatment is targeted at the underlying malignancy with supportive care for pulmonary hypertension.