Differential Diagnosis for Ring Enhancing Lesions on Brain Imaging
- Single most likely diagnosis
- Brain abscess: This is the most common cause of ring-enhancing lesions, especially in the context of fever, headache, and focal neurological deficits. The ring enhancement is due to the central area of necrosis surrounded by a capsule of inflammatory tissue.
- Other Likely diagnoses
- Glioblastoma: A primary brain tumor that can present with ring enhancement due to central necrosis. It is more common in older adults and can cause symptoms such as headache, seizures, and focal neurological deficits.
- Metastatic brain tumor: Brain metastases from extracranial cancers can also present with ring enhancement, especially if they outgrow their blood supply and undergo central necrosis.
- Cysticercosis: A parasitic infection caused by the pork tapeworm, which can cause ring-enhancing lesions in the brain, especially in endemic areas.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subacute infarct: A stroke that occurs in a watershed area can cause a ring-enhancing lesion due to luxury perfusion and breakdown of the blood-brain barrier.
- Toxoplasmosis: An opportunistic infection that can cause ring-enhancing lesions in immunocompromised patients, such as those with HIV/AIDS.
- Fungal abscess: Fungal infections, such as aspergillosis or cryptococcosis, can cause ring-enhancing lesions in immunocompromised patients.
- Rare diagnoses
- Neurocysticercosis with a giant cyst: A rare presentation of cysticercosis where a large cyst forms in the brain and can cause ring enhancement.
- Primary central nervous system lymphoma: A rare tumor that can cause ring-enhancing lesions, especially in immunocompromised patients.
- Melanocytic tumors: Rare tumors that can cause ring-enhancing lesions, such as melanocytomas or melanoma metastases.
- Hemorrhagic transformation of a tumor: Rarely, a brain tumor can undergo hemorrhagic transformation, causing a ring-enhancing lesion.