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Meningeal presentation of an atypical teratoid/rhabdoid tumor A. K. Taneja1, F. Reis1, V. A. Zanardi1, F. Rogerio2, L. S. Queiroz1 Departments of 1Radiology, 2Pathology of the Clinics Hospital of the State University of Campinas, Faculty of Medical Sciences, Campinas, Sao Paulo, Brazil
An 11-year-old boy complained of headache accompanied by vomiting, phonophobia, bilateral proptosis, neckache, hypoesthesia in the face, and decreased hearing acuity on the right side. A few days before admission, the picture was complicated by lumbar pain, walking difficulty, two episodes of tonic-clonic seizures, and diplopia. Physical and neurological examination on admission revealed neck stiffness, positive Kernig and Brudzinski signs, diplopia, and decreased muscle strength in both the lower limbs. There was no significant past medical history. Computed tomography (CT) scan disclosed diffuse contrast enhancement in the cranial leptomeninges, spinal cord, and cranial nerve roots, as well as moderate hydrocephalus. In the anterior region of the left middle fossa, there was a contrast-enhancing nodule [Figure 1a-c]. The findings were confirmed on magnetic resonance imaging (MRI), which showed diffuse leptomeningeal thickening and contrast enhancement over the brain, optic nerves, brain stem, nerve roots, cerebellum, and upper cervical cord. Small nodular formations were observed in the anterior left middle fossa and the bulbo-spinal transition. MRI of the cervical spinal cord showed a contrast-enhancing nodular lesion on its posterior aspect. Cord enlargement with increased signal intensity extended from the bulbo-spinal transition down to C4 [Figure 2]. A new CT scan about 2 weeks
after admission showed intraparenchymal bleeding in the anterior region of the left temporal lobe [Figure 1d]. Histologically, the neoplastic tissue consisted predominantly of small round cells, with high nuclear to cytoplasmic ratio, arranged in sheets. Frequent neoplastic cells with rhabdoid features, numerous mitotic figures, and foci of necrosis were observed. On immunohistochemistry, intense diffuse cytoplasmic positivity was found for epithelial membrane antigen (EMA) and vimentin and, focally, for smooth muscle actin (1A4), desmin, muscle specific actin (HHF35), CD56, and neurofilament. Immunostaining for S-100 protein was positive in both the cytoplasm and the nuclei in variable intensity. Ki67, an antigen expressed by proliferating cells, was detected in approximately 90% of the tumor cell nuclei. These morphological and immunohistochemical data favored the diagnosis of atypical teratoid/rhabdoid tumor (ATRT) [Figures 3 and 4]. At 11 years, the patient was well beyond the expected age at which ATRT usually presents, most cases generally being diagnosed before the age of 4 years. ATRT is usually noted as a voluminous mass localized in the cerebral or cerebellar hemispheres (ratio 1.3:1). In our case, however, no large tumor mass was apparent. Rather, diffuse leptomeningeal spread associated with
Figure 1: (a, b) Axial skull CT scan before and after contrast showing a discrete nodule in the antero-medial aspect of the left temporal lobe, with mild contrast enhancement. (c) Diffuse contrast enhancement of cranial leptomeninges, effacement of cortical sulci and hydrocephalus. (d) Spontaneous intraparenchymal hemorrhage in the anterior region of the left temporal lobe, apparently in association with the nodule detected in earlier scans, about two weeks after admission, which prompted surgical intervention
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Taneja, et al.: Meningeal presentation of atypical teratoid-rhabdoid tumor
Figure 2: MRI, axial T1 weighted images (WI), before (a) and after (b) contrast administration, and T2WI (c) showing extraaxial contrast enhancing nodule in the anterior region of the left temporal lobe. Sagittal contrast enhanced T1WI (d) and T2WI (e) showing nodule in bulbospinal transition, abnormal hyperintensity and swelling of upper cervical cord. Coronal (f) and sagittal (g) T1WI after gadolinium demonstrating widespread leptomeningeal thickening and contrast enhancement
Figure 3: Histological features of the neoplasm. Hematoxylin and eosin staining. The lesion presented essentially as sheets of undifferentiated tumor cells (a) intermingled with necrotic areas (b). Rhabdoid cells with eccentrically placed round, oval or reniform nuclei and occasional large nucleoli were often observed. A few of these cells exhibited an eosinophilic globular cytoplasmic inclusion (arrow) (c). Neoplastic cells showed high mitotic activity (d)
cytoplasmic inclusions. However, this possibility is ruled out by immunohistochemistry[3] which demonstrates an admixture of primitive neuroectodermal, mesenchymal, and epithelial elements.[4] In conclusion, this case of ATRT merits attention because of the late age at presentation, the predominantly diffuse leptomeningeal origin (rather than the usual discrete tumor mass), and the unanticipated bleeding from a minor superficial nodular lesion Address for correspondence: Dr. Atul Kumar Taneja, Rua Oscar Freire, N.2040, AP-164, Pinheiros. São Paulo – SP. CEP 05409-011 E-mail:
[email protected]
Figure 4: Immunohistochemical features of the neoplasm. Tumor cells showed intense cytoplasmic staining for epithelial membrane antigen (EMA) (a), smooth muscle actin (1A4) (b), desmin (c) and neurofilament (d), either with a diffuse (a) or focal (b-d) distribution
minor superficial nodules were the hallmark of the disease. A meningeal origin for this neoplasm has been postulated.[1] Bleeding in the anterior temporal tumor nodule was an unexpected development, which necessitated a surgical approach and, as a byproduct, provided tissue for diagnosis. In the literature, hemorrhage is reported as being common in ATRT (up to 47.4% of cases in one series[2]), but we found no mention of such complication in small superficial lesions or in cases with leptomeningeal tumor spread. The light microscopic features of rhabdoid tumor may mimic gemistocytic anaplastic astrocytoma on account of the eccentric nuclei displaced by eosinophilic
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PMID: *** DOI: 10.4103/0028-3886.68703
References 1.
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Chou SM, Anderson JS. Primary CNS malignant rhabdoid tumor (MRT): report of two cases and review of literature. Clin Neuropathol 1991;10:1-10. Koral K, Gargan L, Bowers DC, Gimi B, Timmons CF, Weprin B, et al. Imaging characteristics of atypical teratoid-rhabdoid tumor in children compared with medulloblastoma. AJR Am J Roentgenol 2008;190:809-14. Kachhara R, Retnam TM, Kumar S, Nair S, Bhattacharya RN, Krishnamoorthy T, et al. Rhabdoid tumor of the thalamus. Neurol India 2003;51:273-4. Rorke LB, Packer RJ, Biegel JA. Central nervous system atypical teratoid / rhabdoid tumours of infancy and childhood: definition of an entity. J Neurosurg 1996;85:56-65.
Accepted on: 10-06-2010
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