Hemangioma: This is the most common benign liver lesion, often found incidentally on imaging studies. Hemangiomas are typically small, well-circumscribed, and have a characteristic appearance on MRI and CT scans, making them a likely diagnosis for a small liver lesion.

Focal Nodular Hyperplasia (FNH): A benign tumor of the liver, second in frequency to hemangiomas. FNH is more common in women and often has a central scar visible on imaging.
Hepatic Adenoma: Although less common than hemangiomas or FNH, hepatic adenomas are benign liver tumors that can be considered, especially in the context of a small lesion, particularly in individuals with a history of oral contraceptive use.
Regenerative Nodule: Can occur in the setting of cirrhosis, representing a benign response to liver injury.

Hepatocellular Carcinoma (HCC): Although less likely for a small lesion, HCC is a critical diagnosis to consider due to its potential for malignancy, especially in patients with risk factors such as cirrhosis, hepatitis B or C infection, or other liver diseases.
Metastasis: In patients with a known history of cancer, even a small liver lesion could represent a metastatic deposit, which would significantly alter management and prognosis.

Biliary Hamartoma (Von Meyenburg Complex): A rare, benign lesion of the liver, often small and multiple.
Intrahepatic Cholangiocarcinoma: A rare malignancy of the bile ducts within the liver, which could present as a small lesion but is much less common than other diagnoses listed here.
Liver Abscess: Although typically associated with larger lesions and clinical symptoms of infection, a small abscess could be considered in the appropriate clinical context, such as recent travel or biliary intervention.
Primary Liver Lymphoma: Extremely rare, but could present as a solitary liver lesion, and is more likely in immunocompromised patients.