INTRODUCTION: Dyspnea is a common symptom in cancer patients, but pulmonary hypertension (PH) is not well defined in this population. Acute cor pulmonale in a cancer patient may be due to cardiac causes, thromboembolism or pulmonary tumor embolism.
CASE PRESENTATION: A 50 year old woman was diagnosed with inflammatory breast cancer metastatic to the contralateral chest and pelvic bones. She received neoadjuvant chemotherapy with docetaxel, doxorubicin and cyclophosphamide followed by modified radical mastectomy. Unfortunately, she was found to have significant residual disease and was started on adjuvant chemotherapy with capecitabine along with radiation therapy to the chest wall. Further staging showed no evidence of disease, and chemotherapy was stopped. Two months later, the patient developed progressive dyspnea and hypoxemia. Work-up at an outside hospital was negative. At our institution, she was found to be tachycardic and tachypneic. Her initial oxygen saturation was 94% on 45% FiO2. On physical examination, she was alert and had clear lung sounds. Her abdominal exam revealed a firm, enlarged liver. No jugular venous distention or pitting edema was present. Laboratory data showed a mild leukocytosis (12,200/UL), carcioembryonic antigen at 596.8 u/mL, aspartate aminotransferase 518 IU/L, alanine aminotransferase 206 IU/L, alkaline phosphatase 175 IU/L, lactate dehydrogenase was noted to be >42,000 IU/L, and arterial blood gas performed on room air showed a pH 7.49, pCO2 33 mmHg and pO2 32 mmHg with 68% saturation. Chest radiography was normal, and CT angiogram of the chest showed no pulmonary embolus, but extensive metastases within the liver. A PET/CT scan demonstrated a mottled appearance of FDG-avid metastases within the liver. The patient was initiated on ixabepilone along with corticosteroids. The patient had progressive hypoxemia, and orthodeoxia with a supine oxygen saturation of 94% that decreased to 85% on standing and a nadir of 67% on ambulation for ten feet. A ventilation-perfusion scan revealed normal ventilation with multiple peripheral, non-segmental perfusion defects in both lungs. An electrocardiogram showed right axis deviation, and a transthoracic echocardiogram revealed a hyperdynamic left ventricle with a severely dilated right ventricle with paradoxical septal motion and elevated right ventricular systolic pressure. The echocardiogram was repeated with agitated saline but did not show right-to-left shunt. Abdominal ultrasound showed no evidence of portal hypertension. Right heart catheterization (RHC) was performed. Pulmonary artery pressure was 77/34 mmHg with a mean pulmonary pressure of 49 mmHg and a pulmonary artery occlusion pressure of 15 mmHg. Further therapy was discussed, but the patient rapidly deteriorated and arrested. Autopsy showed extensive hematogenous dissemination of metastatic carcinoma in bilateral lungs.
DISCUSSION: Acute PH in cancer patients may often suggest thromboembolic disease, but severe PH as noted in our patient suggest either acute on chronic PH or tumor embolus. Tumor embolism to the lung has been reported primarily in autopsy series, but mostly in gastric adenocarcinoma. Pulmonary tumor thrombotic microangiopathy (PTTM) may also manifest with severe PH and is clinically indistinguishable from tumor embolism. PTTM may only be differentiated histologically from tumor embolism, where pathology specifically demonstrates pulmonary vascular obstruction and infiltration with tumor. Additional workup such as a ventilation perfusion scan may reveal multiple subsegmental mis-matched defects. Treatment options are limited, and the condition is often fatal.
CONCLUSIONS: This case illustrates the diagnostic dilemma posed by a patient with metastatic breast cancer that presents with severe acute PH. A high clinical suspicion may facilitate prompt diagnosis and intervention. The effectiveness of chemotherapy, anticoagulation and vasoactive medications, however, has not been well studied in this patient population.
Reference #1 Roberts KE, Hamele-Bena D, Saqi A, Stein CA and Cole RP. Pulmonary Tumor Embolism: A Review of the Literature. Am J Med 2003;115:228-232.
DISCLOSURE: The following authors have nothing to disclose: Mark Warner, Saadia Faiz, Kimberly Koenig, Lavinia Middleton, Peter Kim, Elie Mouhayar, Bela Patel, Lara Bashoura
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