Contributed by Fabio Rogerio, MD, PhD, Luciano de Souza Queiroz, MD, PhD
Department of Pathology, State University of Campinas - Unicamp, Brazil
CLINICAL HISTORY AND IMAGING
A 37-year-old female presented with occipital headache, muscle weakness and paresthesia in the right limbs over 3 months. Magnetic resonance imaging showed a 5 cm solid, contrast-enhancing mass in the left lateral ventricle and adjacent parietal white matter with midline shift, ventricular compression and hydrocephalus (Figure 1). After surgical resection, she was submitted to radiation therapy for 4 months and did well for 3 years, when progressively growing thoracic wall nodules appeared. In the last 2 weeks she complained of paraparesis and hypoesthesia in the lower limbs. Computerized tomography showed lesions in the left clavicle and scapula, sternum and T11 vertebra, the latter causing spinal cord compression (Figure 2). Laminectomy was followed by radiation therapy for the thoracic lesions and chemotherapy. The patient evolved with improvement of muscular strength and relapsing episodes of thoracic pain, controlled with medication. So far there is no radiological evidence of intracranial recurrence. NEUROPATHOLOGICAL FINDINGS
Macroscopic and histologic features of the resected specimens (intracranial and vertebral) were essentially similar. Grossly, the masses were whitish and firm. On hematoxylin and eosin staining, the lesions were hypercellular and consisted of compactly arranged, spindled to oval cells supplied with thin-walled branching vessels (Figures 3 and 4). Mitoses (Figure 4, inset) could reach 4 / 10 high-power fields (hpf) in some areas. Nuclear atypia and necrosis were not identified. Reticulin stain highlighted a predominantly perivascular network, which also wrapped individual cells and small groups (Figure 5). Immunoreactivity was diffuse for vimentin, CD34 (Figure 6) and CD99 (Figure 7); focal for Bcl-2 and negative for GFAP, EMA, S-100 protein, cytokeratins (AE1AE3), estrogen and progesterone receptors, muscle (1A4, HHF-35, desmin) and neuroendocrine (CD56, synaptophysin, chromogranin) markers. Ki-67 index was around 15%. What is the diagnosis?