A 46-year-old woman went to her family doctor after 3 months of abdominal bloating, fatigue, nausea, vomiting, anorexia, and weight loss. Ultrasound imaging revealed hepatic lesions and a mass in the colon; she was diagnosed with colon cancer. The cancer had metastasized to an extent that complete resection wasn’t possible, so she received palliative-intent therapy for the next 18 months.
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Initially, the patient responded to the treatment but then presented to the emergency department (ED) with a severe headache. A CT scan revealed that the cancer had spread to her brain. However, this time resection was possible, and she recovered well.
Three weeks later the patient was back in the ED with an infection. A new CT scan showed no evidence of abscess (one of the differential diagnoses). A transthoracic echocardiogram showed a right atrial lesion, and further imaging confirmed a lesion in the right atrium. “Unexpectedly,” her clinicians reported, the lesion originated from the distal inferior vena cava (IVC): She had shown no signs of symptoms of pulmonary embolus or occlusion of the IVC.
Tumor thrombus is rarely reported with colorectal cancer cases, so the patient’s clinicians at first thought the mass in the IVC was bland thrombus, managed with anticoagulation alone. The clinicians felt that the assumption was reasonable, given the link between malignancy and venous thromboembolism; also because the patient had an indwelling central venous catheter. Contrast-enhanced CT scan and contrast-enhanced ultrasound, however, supported the diagnosis of tumor thrombus.
Due to the rarity of tumor thrombus in colorectal cancer, there are no guidelines for diagnosis and management, the clinicians say. In the patient’s case, consultation with cardiologists, radiologists, and gastrointestinal specialists at the cancer center resulted in an offer to extract the thrombus, but the risks and the fact that she was asymptomatic led the patient to decline. She was instead restarted on palliative chemotherapy with heparin in case part of the thrombus was indeed bland thrombus.
The patient’s condition deteriorated over the next 3 months. She and her team agreed that supportive care at home was best. The patient still had no symptoms from the tumor thrombus when she died.
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Autopsy supported the suspicion that the original lesion was partly tumor thrombus and partly bland thrombus, reduced by anticoagulation. But autopsy results revealed no embolization of tumor thrombus or bland thrombus into the pulmonary arteries, although there were extensive metastases in the brain, lung, liver, adrenals, and ovaries. Ultimately, the patient’s death was attributed not to the tumor thrombus that extended into the right atrium but to multiorgan failure due to cancer--validating the decisions to not choose surgery for the thrombus.
Source:
Meyers D, Nixon NA, Franko A, Ng D, Tam VC. BMJ Case Rep. 2017;2017:pii:bcr2016218107.
doi: 10.1136/bcr-2016-218107.