Confused Patient, Puzzled Doctor

Meeting: Hospital Medicine 2012, April 1-4, San Diego, Calif.

Abstract number: 97768

Case Presentation:

A 70–year–old man presented with confusion, mumbling, malaise, and headache after having recently taken oral antibiotics for a skin lesion on his forehead. His prior history was complicated by previously treated chronic lymphocytic leukemia (CLL) resulting in hypogammaglobulinemia with multiple infections including viral encephalitis. Lumbar puncture was remarkable for a lymphocytic predominance in his cerebrospinal fluid (CSF) with 87 white cells and 1 red cell per high powered field. The differential had 87% lymphocytes and 13% monocytes. Bacterial culture, cytology, and brain MRI were unremarkable. He was empirically started on acyclovir and improved within 2–3 days. He was discharged with a presumed diagnosis of viral meningitis on acyclovir with herpes simplex virus (HSV) PCR still pending. After discharge, the HSV PCR was negative, and the patient worsened with myoclonic jerking, personality changes, memory loss and decreased executive function requiring a return to the emergency department ten days later. Repeat lumbar puncture was performed, and the CSF leukocyte count increased to 377 with 92% lymphocytes. The CSF protein level increased to 175. Serum white blood cell count was 8000 with a differential of 43% neutrophils, 44.9% lymphocytes, and 9.6% eosinophils. A full infectious workup was negative including screening for enteroviruses, arboviruses, all herpes viruses, mumps, coxsackie viruses, influenza, adenovirus, cryptococcus, fungus, atypical mycobacteria, and bacteria. Given the patient’s history of CLL, flow cytometry was performed, and this showed lambda light chain restricted B cells consistent with extension of CLL into the central nervous system (CNS).


CNS involvement is quite rare in CLL with only 80 known case reports to date. Other types of lymphoma found in the CNS include primary CNS lymphoma and metastatic non–Hodgkin’s lymphoma. As seen in this patient, these can present with many non–specific symptoms including cranial nerve palsies, confusion, personality changes and SIADH. The limitations of using cytology to analyze CSF for neoplasm was also demonstrated in this case. To obtain the best analysis, 10–15 ml of CSF are needed immediately. In this patient, the first cytologic analysis was requested late in the hospital course, and was subsequently negative, possibly due to poor cellular preservation. Specificity of cytology in the CSF can be greater than 95%, but sensitivity is only roughly 50%. However, flow cytometry has been thought to increase likelihood of diagnosis by being complementary to cytology. Other common findings for CNS lymphoma include lymphocytic predominance and elevated protein levels.


Aseptic meningitis is common in the hospitalized patient; however, it should be noted that infection is not the only cause of leukocytes in the cerebrospinal fluid. Leukemia and lymphoma are rare to find in the CNS, but should remain on the differential diagnosis if delirium from aseptic meningitis is not improving.

To cite this abstract:

Hepper A. Confused Patient, Puzzled Doctor. Abstract published at Hospital Medicine 2012, April 1-4, San Diego, Calif. Abstract 97768. Journal of Hospital Medicine. 2012; 7 (suppl 2). Accessed April 8, 2020.

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