Metastasis: This is often the most common cause of liver hypoechoic lesions, especially in patients with a known history of cancer. The liver is a common site for metastasis due to its rich blood supply, making it a prime location for cancer cells to spread.

Hepatocellular Carcinoma (HCC): A primary liver cancer that can present as hypoechoic lesions, especially in patients with risk factors such as cirrhosis, hepatitis B or C infection, or alcohol abuse.
Hemangioma: Although typically hyperechoic, some hemangiomas can appear hypoechoic, especially if they are small or have undergone degenerative changes.
Focal Fatty Change: Areas of fatty infiltration in the liver can appear hypoechoic and are often associated with conditions like obesity, diabetes, or heavy alcohol use.

Abscess: A liver abscess can present as a hypoechoic lesion and is a medical emergency requiring prompt drainage and antibiotic treatment. It's crucial not to miss this diagnosis due to its high morbidity and mortality if left untreated.
Cholangiocarcinoma: A cancer of the bile duct that can cause hypoechoic lesions in the liver. Early detection is critical for treatment, making it a "do not miss" diagnosis.

Lymphoma: Primary or secondary lymphoma involving the liver can present as hypoechoic lesions, though this is less common.
Intrahepatic Cholangiocarcinoma: A subtype of cholangiocarcinoma that arises from the intrahepatic bile ducts and can appear as hypoechoic lesions.
Hepatic Sarcoidosis: A condition where granulomas form in the liver, which can sometimes appear as hypoechoic lesions on ultrasound, though this is rare and usually part of systemic sarcoidosis.