A 63-year-old man comes to the office due to anorexia and weight loss for the past 2 months. He has no chest pain, abdominal pain, cough, or fever. His medical problems include hypertension and latent tuberculosis treated 30 years ago. He does not use tobacco, alcohol, or illicit drugs. Temperature is 37.5 C (99.5 F), blood pressure is 124/80 mm Hg, pulse is 78/min, and respirations are 14/min. Physical examination reveals mucosal pallor and mild hepatomegaly. The abdomen is soft, nondistended, and nontender. Cardiopulmonary examination is normal. Fecal occult blood testing is positive. Laboratory results are as follows:
Complete blood count Hemoglobin 9.8 g/dL Mean corpuscular volume 72 µm3 Platelets 276,000/mm3 Leukocytes 6,700/mm3 Liver function studies Total bilirubin 1.3 mg/dL Alkaline phosphatase 190 U/L Aspartate aminotransferase (SGOT) 32 U/L Alanine aminotransferase (SGPT) 38 U/L
Ultrasound reveals a solitary liver lesion measuring 2x3 cm. Which is the most likely diagnosis?
Solid liver masses | |
Focal nodular hyperplasia |
|
Hepatic adenoma |
|
Regenerative nodules |
|
Hepatocellular carcinoma |
|
Liver metastasis |
|
Metastatic disease is the most common cause of liver mass and is much more common than primary liver cancer. Undiagnosed colorectal cancer (CRC) is likely in this patient with a solitary liver mass, probable iron deficiency anemia (low mean corpuscular volume), and positive fecal occult blood screen. Gastrointestinal malignancies, such as colorectal or pancreatic cancer, are the most frequent source of liver metastases as their venous drainage is through the portal system directly to the liver. Lung, breast, and skin cancers (melanoma) often also spread to the liver. The liver is a common site of metastatic disease due to its dual blood supply (systemic and portal) and hepatic sinusoidal fenestrations allowing for easier metastatic deposition.
Liver metastases are often clinically silent unless pressure on the liver capsule or obstruction of the biliary tree causes pain or jaundice. Results of hepatobiliary laboratory testing (eg, alkaline phosphatase) may be normal or mildly elevated, even in the setting of heavy tumor burden. Multiple hepatic nodules are typically seen in metastatic disease; however, solitary lesions are not uncommon. If a primary tumor is identified (eg, with colonoscopy), liver biopsy is usually not needed.
(Choice A) Hepatic angiosarcoma is a rare liver neoplasm more common in older men who have been exposed to toxins (eg, vinyl chloride gas, inorganic arsenic compounds, thorium dioxide).
(Choice B) Cholangiocarcinoma typically presents with symptoms of biliary obstruction - jaundice, pruritus, light-colored stools, and dark urine. The main risk factor is a history of primary sclerosing cholangitis.
(Choices C and D) Focal nodular hyperplasia (FNH) and hepatic adenoma are usually benign liver tumors seen in young women. FNH is typically asymptomatic; hepatic adenoma may cause right upper quadrant pain and is associated with oral contraceptive use.
(Choice E) Primary hepatic tuberculosis is rare due to the low oxygen tension in the liver. Even with disseminated tuberculosis, a solitary liver mass would be unlikely.
(Choice F) Hepatocellular carcinoma (HCC) typically emerges from a chronically inflamed liver (eg, chronic hepatitis B or C infection). HCC is the most common type of primary liver cancer but is a far less common cause of hepatic malignancy than metastasis from another source. Microcytic anemia and a positive fecal occult blood screen make CRC more likely in this patient.
Educational objective:
The most common malignancy of the liver is metastasis from another primary source.