Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 58, Num. 4, 2010, pp. 681-682

Neurology India, Vol. 58, No. 4, July-August, 2010, pp. 681-682

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Meningeal presentation of an atypical teratoid/rhabdoid tumor

Taneja AK, Reis F, Zanardi VA, Rogerio F, Queiroz LS

Department of Radiology of the Clinics Hospital of the State University of Campinas, Faculty of Medical Sciences, Campinas, Sao Paulo

Correspondence Address:Rua Oscar Freire, N.2040, AP-164, Pinheiros. São Paulo - SP. CEP 05409-011, atultaneja@gmail.com

Date of Acceptance: 10-Jun-2010

Code Number: ni10188

PMID: 20739832

DOI: 10.4103/0028-3886.68703

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 - 1]a-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 - 1]d.

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) [Figure - 3] and [Figure - 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 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 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

References

1.	Chou SM, Anderson JS. Primary CNS malignant rhabdoid tumor (MRT): report of two cases and review of literature. Clin Neuropathol 1991;10:1-10.   Back to cited text no. 1  [PUBMED]
2.	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.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.	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.  Back to cited text no. 3  [PUBMED]
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.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]

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