Posterior fossa Hodgkin's lymphoma radiographically mimicking an arteriovenous malformation: illustrative case

Abstract

Background: Intracranial Hodgkin's lymphoma (HL) is an exceedingly rare condition that is at an increased risk of misdiagnosis and mismanagement, especially when initial radiographic evidence points to an alternative pathology.

Observations: The authors describe the case of a 75-year-old female who presented with a posterior fossa lesion initially concerning for a vascular malformation on computed tomography imaging due to perilesional hypervascularity. Subsequent angiography revealed a developmental venous anomaly (DVA) but no arteriovenous shunting. The patient's clinical history combined with magnetic resonance imaging findings prompted a tissue biopsy, which demonstrated a rare case of central nervous system (CNS) HL. The neoangiogenesis of this CNS HL with an adjacent DVA contributed to the original radiographic misdiagnosis of an arteriovenous malformation. HL's angiogenic potential, coupled with the proangiogenic environment induced around DVAs, may have contributed to this rare CNS HL metastasis to the cerebellum. The potential misdiagnosis of posterior fossa CNS HL has also been seen in several prior cases reviewed herein.

Lessons: Hypervascular tumors, especially when associated with an adjacent DVA, should also be considered when first evaluating suspected intracranial vascular lesions. Although rare, CNS HL should be included in the differential diagnosis for patients with a prior history of HL. https://thejns.org/doi/10.3171/CASE24238.

Keywords: central nervous system Hodgkin’s lymphoma; developmental venous anomaly; intracranial Hodgkin’s lymphoma; neuroradiology; posterior fossa lymphoma metastasis.

FIG. 1.

Axial (A) and coronal (B) noncontrast head CT images from admission showing a 2.2 × 2.3–cm hyperdensity in the medial aspect of the right cerebellar hemisphere with moderate surrounding edema and crowding of the posterior fossa. Corresponding axial (C) and coronal (D) CT angiograms of the head reveal a prominent abnormal vessel superolateral to the hyperdense lesion, as well as some hypervascularity noted circumferentially around the lesion (best seen on the coronal image). Anteroposterior (E) and lateral (F) images from the early venous phase of a right vertebral artery injection, as part of a diagnostic catheter angiogram, reveal the presence of a large right superior cerebellar DVA (blue arrowheads) draining toward the tentorium and the torcula with no evidence of arteriovenous shunting.

FIG. 2.

Coronal (A) and axial (B) postcontrast T1-weighted MRI at the level of the medulla and the pons (C) showing a homogeneously enhancing right paramedian cerebellar lesion with irregular borders and the previously noted large venous anomaly superolateral to the lesion. Axial T2 fluid-attenuated inversion recovery MRI (D) at the level of the pons demonstrating significant edema surrounding the lesion and extending to the right brachium pontis and medial left cerebellar hemisphere. A flow void is notable at the area of the venous anomaly. Axial diffusion-weighted MRI (E) and ADC map (F) showing moderate diffusion restriction throughout the right cerebellar lesion. MRS (G) of the right cerebellar mass demonstrating an elevated choline/creatine ratio and elevated lipid peaks suggestive of a malignant neoplasm, especially concerning for lymphoma.

FIG. 3.

Histopathological findings from the needle biopsy. Bar (applicable to all panels) = 50 µm. Hematoxylin and eosin staining (A) showing a lymphocytic infiltrate with scattered large atypical mononuclear lymphoid cells consistent with Hodgkin cells and multinucleated Reed-Sternberg cells with prominent nucleoli and abundant cytoplasm. In situ hybridization for Epstein-Barr virus–encoded RNA (B) showing positivity in the Reed-Sternberg neoplastic cells. Immunohistochemistry for CD20 (C) with nonspecific scarce staining. Immunohistochemistry for CD30 (D) showing positive membranous and perinuclear/Golgi apparatus immunoreactivity in the Reed-Sternberg neoplastic cells.