Differential Diagnosis for Scattered Hypodensities on the Liver

Single Most Likely Diagnosis

• Fatty Liver Disease: This condition is characterized by the accumulation of fat in liver cells and is a common cause of hypodensities on liver imaging, especially in the absence of other significant medical history. It can be associated with alcohol use, obesity, or metabolic syndrome, but can also occur without these risk factors.

Other Likely Diagnoses

• Hemangiomas: These are benign liver tumors composed of blood vessels. They are common and can appear as hypodense lesions on imaging, especially on CT scans without contrast.
• Liver Metastases: Although the patient has no past medical history, it's essential to consider metastatic disease, especially if there's an unknown primary malignancy. Metastases can appear as multiple hypodense lesions.
• Pyogenic Liver Abscesses: These are collections of pus in the liver, usually due to bacterial infection. They can present as hypodense areas on imaging and are more likely in patients with a history of biliary disease or recent travel, but can occur without these risk factors.

Do Not Miss Diagnoses

• Liver Hydatid Cysts: Caused by the parasite Echinococcus, these cysts can appear as hypodense lesions in the liver. Although less common, missing this diagnosis could lead to significant morbidity if the cysts rupture or become infected.
• Amebic Liver Abscesses: Similar to pyogenic abscesses but caused by the parasite Entamoeba histolytica. These can also present as hypodense lesions and require specific treatment to avoid complications.
• Malignant Tumors (Primary or Metastatic): While less likely without a known primary cancer, it's crucial not to miss a diagnosis of liver cancer, either primary (like hepatocellular carcinoma) or metastatic, as early detection can significantly impact treatment and prognosis.

Rare Diagnoses

• Polycystic Liver Disease: A rare genetic disorder characterized by the growth of numerous cysts filled with fluid in the liver. It can present with hypodense areas on imaging due to the cysts.
• Lymphoma Involving the Liver: Although rare, lymphoma can involve the liver and present as hypodense lesions. This would typically be associated with systemic symptoms or known lymphoma.
• Granulomatous Liver Disease: Conditions like sarcoidosis can cause granulomas in the liver, which might appear as hypodense lesions on imaging. This diagnosis is less common and usually associated with other systemic symptoms or findings.