What infection is suggested by a ring-enhancing lesion with mass effect on MRI?

A ring-enhancing lesion with mass effect on MRI can be indicative of several different conditions, including abscess formation, central nervous system (CNS) lymphoma, and toxoplasmosis. Each of these conditions can present in a similar manner on imaging studies, leading to the correct choice being that all of these infections ought to be considered.

Abscess formation, particularly in the brain, often presents as a ring-enhancing lesion due to the surrounding edema and inflammatory response. This can occur from various infectious agents, including bacteria or fungi.

CNS lymphoma, which is a type of primary brain tumor, can also appear as a ring-enhancing lesion. These tumors typically present in immunocompromised patients, like those with HIV, and can create significant mass effect due to their growth.

Toxoplasmosis is another key consideration, especially in patients with HIV/AIDS. Toxoplasma gondii causes a characteristic appearance of ring-enhancing lesions, often found in the basal ganglia, and is the most common cause of CNS lesions in immunocompromised individuals.

Because each of these conditions can indeed present as ring-enhancing lesions on MRI with associated mass effect, consideration of all these potential causes is essential in making an accurate diagnosis. Therefore, the