Case Presentation: A 64-year-old male with past medical history of coronary artery disease, hypertension and weight loss of 20 pounds within 4 months presented to the hospital after he had a seizure-like activity of his upper body lasting around 10 minutes accompanied by altered mentation. Upon arrival to the emergency department, his symptoms had resolved. However, he became altered again and a stroke alert was called. Computed tomography (CT) of the head revealed an extra-axial mass along anterior falx as well as left superior frontoparietal convexity with surrounding vasogenic edema and mass effect. Patient was given a loading dose of levetiracetam, dexamethasone and electroencephalogram (EEG) was started. Laboratory findings were unyielding for any obvious source of infection. Patient underwent magnetic resonance imaging (MRI) of the brain which showed two dural based tumors-one measuring 3.8cm x 2.6cm x 2.6cm extending to bilateral frontal lobes, more prominent on the left and the second tumor in the left frontoparietal convexity measuring 2.8cm x 2.2cm x 1.4cm. CT of the chest, abdomen and pelvis ruled out any primary malignancies. EEG was negative for epileptiform discharges and seizures. Patient was discharged on levetiracetam 750mg twice daily, dexamethasone taper with instructions to return for surgery. Patient underwent elective left craniotomy for mass resection of tumors. Post operative CT of the head showed improved edema and reduction of midline shift with decrease in size of the extra axial masses. Pathology revealed chronic lymphohistiocytic and plasmacytic inflammation involving meninges and dura with extension into the brain parenchyma and proliferation of the fibroconnective tissue. Immunohistochemistry was positive for S100, CD3, CD20, CD31, CD45, CD68. CD1a and desmin were negative. Histopathology demonstrated minimum amount of possible acid-fast rods (AFB). Patient underwent lumbar puncture which revealed clear, colorless cerebrospinal fluid (CSF) with 5 WBC/microliter. CSF culture was negative. Patient was started on isoniazid, rifampicin, ethambutol, pyrazinamide with vitamin B6 regimen. AFB culture was negative after 8 weeks. Follow up magnetic resonance imaging of the brain showed resolution of the lesions.
Discussion: Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytic proliferative disorder. Painless bilateral cervical lymphadenopathy is a common clinical presentation. Central nervous system involvement is described in less than 5% of the cases. Neurologic involvement may present as headache, seizures or gait disturbances.
Conclusions: Extranodal RDD, isolated intracranial lesions are usually dural-based and clinically mimic meningiomas. Immunohistochemical examination is positive for S-100 protein and negative for CD1a, a marker of Langerhans histiocytosis. Surgical resection is the most effective treatment. Our patient presented with clinical features of meningioma and tuberculoma and was finally diagnosed with RDD with possibility of tuberculosis infection on the brain tumor pathology. Extranodal RDD can be easily missed and should be considered in the differential diagnosis of patients who present with dural based tumors.