Contributed by Marian Christoph Neidert,1 Henning Leske2, Jan-Karl Burkhardt1, Elisabeth Jane Rushing2 , and Oliver Bozinov1
1 University Hospital Zurich, Department of Neurosurgery, University of Zurich, Frauenklinikstr.10, CH-8091 Zurich, Switzerland
2 University Hospital Zurich, Department of Neuropathology, University of Zurich, Schmelzbergstr.12, CH-8091 Zurich, Switzerland
A 44-year-old man with a past medical history of arterial hypertension, hypercholesterolemia, cigarette smoking (45 pack-years) and obesity (BMI 32.8) presented to our department with a 3-month history of right-sided facial numbness. Four weeks prior to admission he experienced a single episode of involuntary muscle movements on the left-side of his body. His neurologic exam was normal and initial laboratory results including CBC and blood chemistry were within normal range. A magnetic resonance imaging (MRI) scan of the patient's brain (Figure 1) showed a 7.3x4.9x3.6 cm, right fronto-parietal, extra-axial space-occupying lesion with lobulated contrast-enhancement and mild perifocal edema. The superior sagittal sinus was slightly compressed and the overlying cranium was infiltrated. The patient underwent angio-embolization of the lesion and two days later a right fronto-temporo-parietal craniectomy was performed. The tumor was resected subtotally, leaving a thin superficial infiltrative layer on eloquent cortex. The infiltrated cranium was reconstructed using polymethyl-methacrylate (PMMA) cranioplasty and the resected dura was replaced by a neuropatch. Postoperatively, an MRI of the spine and a lumbar puncture did not show any evidence for disease dissemination. The patient had no neurological deficit and underwent adjuvant radiation therapy of the tumor bed (36 Gy) and 2-years after diagnosis he was clinically and radiologically disease-free.
Microscopic examination of the biopsy revealed fragments of dense connective tissue infiltrated by closely-packed, medium-sized, monomorphic lymphocytes and scattered plasma cells (Figures 2 and 3). Occasional thrombosed vessels surrounded by necrotic tissue were seen. The lymphocytic infiltrates were positive for CD20 (Figure 4), CD45 (Figure 5), BCL2 (Figure 6), and CD79a (Figure 7) and negative for EMA, CD34, TDT and CD99. In addition, there were smaller collections of CD3 (Figure 8) and CD23 (Figure 9) positive lymphocytes, which were often perivascular, with rare cells staining for CD5 (Figure 10) and CD10 (Figure 11). Ki-67 immunostaining showed a patchy distribution, labeling up to 30% (average, 10%) of the neoplastic cells. What is your diagnosis?