An unusual presentation of primary malignant B-cell-type dural lymphoma

Abstract

Primary malignant B-cell-type dural lymphoma is a rare subtype of primary central nervous system lymphoma (PCNSL). We herein report an unusual case of diffuse B-cell lymphoma that presents as a chronic subdural haematoma without extracranial involvement. The notable aspects of this case include the patient's immunocompetence, a short clinical history of symptom onset, rapid neurological deterioration and a fi nal diagnosis of high-grade PCNSL. This case highlights the challenges neurosurgeons face, especially in the emergency setting, when the disease manifests in varied presentations.

Fig. 1

Pre-contrast axial CT image shows the patient’s brain.

Fig. 2

T1-weighted post-gadolinium MR image shows the extra-axial polypoidal nipple, which was thought to be a proliferation of granulation tissue (arrow).

Fig. 3

Photomicrographs of the lesional tissue show (a) the dura at the bottom right, under low magnification (Haematoxylin & eosin); and (b) sheets of neoplastic cells with brisk mitotic activity, under high magnification (Haematoxylin & eosin). The neoplastic cells contain enlarged vesicular nuclei with small but conspicuous nucleoli, and show (c) strong and diffuse immunostaining for CD20; and (d) marked MIB-1 labelling index.

Fig. 4

Photomicrographs of the immunostains of the neoplastic cells show positive tests for (a) BCL2 and (b) CD43. Photomicrographs of the scattered cells show (c) positive staining for CycD1; and (d) a small population of reactive CD5-positive T lymphocytes.