1. Presented by Lucy Nam, JHU medical student and reviewed by Karen Carroll, MD

Clinical Vignette

A previously healthy adult presents from an outside hospital after reportedly having severe headaches for the past several months, followed by recent development of neck pain and memory problems. In the preceding weeks, the patient developed a cough and runny nose, and suffered several falls. Several days prior to admission, the patient presented to the outside hospital where imaging was performed. The MRI showed a frontal skull base lesion with a small lesion in the parietal area surrounded by significant edema (Figure 1). The CT scan of the chest, abdomen and pelvis showed left upper lung ground glass appearance, concerning for inflammatory changes. The patient was promptly transferred to another institution for neurosurgical management. A biopsy of the brain was stained and revealed the structures in Figure 2.

Prior to this incident, the patient had no significant health issues. Over the past several months, the patient lost approximately 30 pounds. The patient is has never had HIV testing performed.

On exam, the patient had a mild fever (99°) and all other vital signs were stable. The neck was supple and not rigid on exam. The abdomen was soft, nondistended, and without appreciable organomegaly. The neurological exam was grossly intact, without focal deficits and no obvious cranial nerve palsies. The labs are significant for decreased hemoglobin (11.1 g/dL), decreased hematocrit (34.3%), mild hyponatremia (134 mEq/L), and elevated glucose (137 mEq/L).

Figure 1. MRI demonstrating brain lesions

 



Figure 2. Histologic findings on brain biopsy (hematoxylin and eosin stain, 100x)



Question: Which is the most likely diagnosis in this patient?