Causes of lower limb edema in liver cancer with renal metastasis

The patient was diagnosed with liver cancer ten months ago and is now in the advanced stage with renal metastasis. He currently has paroxysmal pain in the liver area, shoulder pain, and lower limb edema. I would like to know whether lower limb edema is related to renal metastasis?

Judging from the patient's condition, there are cases of renal and abdominal metastasis, so the lower limb edema is still considered to be related to renal metastasis. However, clinically, liver cancer patients without renal metastasis may also have lower limb edema.

Why do liver cancer patients experience lower limb edema?

Edema caused by liver cancer can occur in the ankles in mild cases and spread to the entire lower limbs in severe cases.

Mild edema is caused by damaged liver function in liver cancer patients, which affects the absorption of protein. Hypoproteinemia will cause edema all over the body, which is a manifestation of low immunity of the body.

The main cause of severe edema is ascites compressing the lower limb veins or cancer thrombus blockage, which obstructs venous return and causes lower limb edema. In patients with severe edema, water can seep directly from the thigh skin.

Why does liver cancer metastasis to the kidney also cause lower limb edema?

The kidneys are the body's filters, excreting metabolic products through the glomeruli. Kidney cancer affects the kidney's reabsorption and filtration functions, which may lead to reduced filtration and excessive water accumulation in the body, causing lower limb edema.

Considering that this patient had advanced liver cancer with renal metastasis, there were many reasons for the occurrence of lower limb water retention, and it was not necessarily caused by renal metastatic cancer alone.