Teaching NeuroImage: Branching Dura Mater in Primary CNS ALK-Positive Anaplastic Large Cell Lymphoma

A 22-year-old man presented with new-onset, gradually progressive diffuse headache for 2 months. He exhibited no apparent physical or neurologic abnormalities except for limited bilateral lateral rectus movement and bilateral papilledema on fundoscopic examination. An MRI examination of the brain showed multiple nodular-enhancing lesions along both sides of the falx cerebri with perilesional edema. In addition, these nodular structures formed a branching network of thickened dura mater to adjacent nodular structures (Figure 1). Due to these atypical features, the differential diagnosis included tuberculosis, sarcoidosis, immunoglobulin G4-related disorders, lymphoproliferative disorders, meningioma, hemangiopericytoma, and Erdheuim-Chester disease.1 A stereotactic biopsy was performed. The pathologic and immunohistochemistry results and systemic evaluation were compatible with primary CNS anaplastic large cell lymphoma with ALK+.2 After a total of 6 courses of high-dose methotrexate and ifosfamide followed by whole-brain radiation, the patient achieved complete remission and resolution of headache (Figure 2).

Automated summary

This article reports a case of a 22-year-old man who presented with new-onset, gradually progressive diffuse headache. The patient exhibited limited bilateral lateral rectus movement and bilateral papilledema on fundoscopic examination. Brain MRI revealed multiple nodular-enhancing lesions along both sides of the falx cerebri, forming a branching network. After treatment, the patient achieved complete remission and resolution of headache.