Radiological Case: Primary CNS Lymphoma of the Choroid Plexus

Max S Fleisher, BA; Kaitlyn Barkley, MD; Maryam Rahman, MD, MS; John H Rees, MD


Appl Radiol. 2020;49(2):35-37. 

In This Article

Case Summary

A 79-year-old presented with a one-month history of headaches worsened by lying flat. The patient had blurred vision, cognitive decline, disequilibrium, and hearing difficulty. On exam, the patient was neurologically intact. Initially, a head CT scan showed right temporal hypodensity concerning for infarction. An MRI scan showed multiple enhancing lesions of the choroid plexus (Figure 1). Cerebrospinal fluid analysis showed low glucose and significantly elevated protein. Flow cytometry and cytology were negative. An infectious workup was also negative.

Figure 1.

Axial (A) and coronal (B) T1 MRI images with contrast demonstrate enhancing choroid plexus lesions from lateral ventricles to temporal horns. Nodular enhancing lesions in the third ventricle, foramen of Monro, and in the fourth ventricle extending to the foramen of Luschka are also present. (C) T2 FLAIR sequence demonstrates significant vasogenic edema surrounding the lesion.

The patient underwent right endoscopic cranial excisional biopsy of tumor with external ventricular drain placement, and biopsy results revealed aggressive B-cell lymphoma (Figure 2).

Figure 2.

Tissue sections show an aggressive B-cell lymphoma. H&E stained sections (A) show atypical lymphocytes with pleomorphic large nuclei, prominent nucleoli, increased mitoses and apoptosis. CD20 (B) and Ki-67 (C) are consistent with the diagnosis. Original magnification ×400 (A); ×100 (B): ×100 (C).

The patient was treated with high-dose methotrexate and rituximab. An MRI scan 2 weeks later showed improvement of the avidly-enhancing intraventricular and cerebellopontine angle lesions.