Pulmonary embolism from a venous thrombus located below the knee

Area of Science:

• Cardiology
• Oncology
• Radiology

Background:

• Bronchogenic carcinoma is a significant risk factor for venous thromboembolism.
• Deep vein thrombosis (DVT) typically affects the calf, and distal thrombi are often considered low risk.

Observation:

• A patient with lung cancer developed acute thrombophlebitis below the knee.
• The patient subsequently experienced a pulmonary embolism.

Findings:

• Diagnostic imaging, including nuclear venography and lung scans, confirmed complete embolization of the below-knee thrombus.
• The patient's clinical presentation indicated that the distal thrombus caused significant pulmonary disease.

Implications:

• This case challenges the traditional view of distal DVTs as benign.
• It suggests that anticoagulation therapy may be warranted for below-knee thrombi in specific clinical contexts, particularly in cancer patients.
• Further research is needed to define criteria for anticoagulation in such cases.