【One case per day】 Liver metastases

At the age of 51, bowel habits change

CT-enhanced scan of the abdomen

What is the most likely diagnosis?

1.

2.

3.

4.

5.

【Answer】

4.

【Discussion】

Liver metastases

【Overview】

1.

2.

Only lymph nodes accumulate more than liver metastases

3.

4.

(1) Colon

(2) Stomach

(3) Pancreas

(4) Mammary glands

(5) Lungs

(6) Eyes

5.

(1) Neuroblastoma

(2) Nephroblastoma (Wilms tumor)

(3) Leukemia

6.

Multiple lesions often vary in size and suggest intermittent tumor dissemination

7.

Liver function tests are often insensitive and nonspecific

8.

9.

【Pathological characteristics of metastasis】

1.

2.
In general, most metastases are hypogenetic, but some primary foci have typical blood-rich metastases

3.
Blood-rich blood supply metastases:

(1) Carcinoid carcinoid carcinoid

(2) Leiomyosarcoma

(3) Neuroendocrine tumors

(4) Kidney cancer

(5) Thyroid cancer

(6) Choriocarcinoma

(7) Occasionally pancreatic cancer, ovarian cancer or breast cancer

4.
All metastases have increased blood flow, even if there is less blood supply to the tumor

5.
Neoangiogenesis, vascular sleeve and arteriovenous fistula are rare

6.
Large metastases can lead to central necrosis due to insufficient blood supply

【Liver blood supply】

1.
The liver has a dual blood supply from the hepatic artery (25%) and portal vein (75% of the liver blood flow).

2.
Arterial blood is supplied by the hepatic artery

3.
Portal vein drains venous blood from the gastrointestinal (GI) tract and other parts of the internal organs

Portal blood supplies 50-60% of the oxygen demand of the liver, and the rest is supplied by hepatic artery blood

4.
Hepatic vein drainage is the hepatic vein and the short hepatic vein directly from the caudal lobe to the inferior vena cava (IVC).

Hepatic veins are drained through the inferior vena cava (IVC) to the right atrium

【Imaging manifestations of liver metastases】

1.
Routine X-ray plays little role in the diagnosis of liver metastases

2.
Plain abdominal X-ray may indicate hepatomegaly or ascites

3.
Calcified metastases can be seen in individual primary tumors, usually ovarian cancer or colorectal cancer that secretes mucus

Calcification in metastases is often irregular

【CT performance】

(1) CT is the preferred method for assessing liver metastases

(2) CT is the most sensitive technique for finding liver metastases (enhanced scan sensitivity 80-90%, specificity 99%)

(3) Most liver metastases have less blood supply relative to the surrounding liver parenchymum, so most lesions are low or equal density relative to the surrounding normal liver

(4) Most studies of metastatic lesions of the liver are enhanced scans

Enhanced testing makes it easier to detect lesions of oligoblood supply

(5) Enhancement scan liver metastases can be marginally slightly strengthened, and the center is low density

(6) The edge of the lesion is clear or unclear

(7) Blood-rich lesions are uncommon

In the venous phase, some blood-rich primary tumors may be of equal density relative to the liver parenchyma, such as: renal cell carcinoma, islet cell tumor, pheochromocytoma, melanoma, and breast cancer

【Differential diagnosis】

1.
Multiple hemangiomas can be misdiagnosed as metastases

2.
No fortified cysts

3.
Focal nodular hyperplasia (FNH) - can be similar to blood-rich supply metastases

4.
Hepatic islands on the background of diffuse fatty liver can mimic metastases

【MRI performance】

1.
MR is usually used in the diagnosis of problems with liver metastases and is not the test of choice

2.
Most benign or malignant liver tumors have a low signal and a high signal of T2WI

3.
MRI gadolinium agent enhancement can improve the ability to detect focal liver masses and the ability to distinguish between benign and malignant lesions

4.
MRI can confirm the diagnosis of hemangioma

【Conventional ultrasound (US) performance】

1.
Ultrasound (US) performance of liver metastasis has no specificity

2.
Large liver

3.
The surface of the liver can be nodular or lobed

4.
Multiple nodules of varying sizes in the liver are almost always due to metastases

liver metastases, CT-enhanced scans:

In patients with coloral cancer, there are many low-density shadows of varying sizes and blurred
edges in the left and right lobes of the liver.