Atypical teratoid/rhabdoid tumor of the brain? A case with three secondary implants

Atypical teratoid/rhabdoid (AT/RT) of the brain is a rare malignant pediatric neoplasm that usually affects children around age two. This report is about a male patient, six months of age, who presented with seizures and decreased level of consciousness, progressing to numbness, oculomotor nerve palsy and tetra-spasticity. CT scan showed left cerebellopontine angle tumor. Magnetic resonance imaging (MRI) showed a solid lesion, hypointense on T1W and heterogeneous hyperintense on T2W, enhanced after contrast infusion, accompanied by three solid lesions, rounded and irregular in the left cerebellar hemisphere, occipito-parietal transition and right occipital lobe with no evidence of leptomeningeal spread, forming secondary implants. We conducted a biopsy, which confirmed AT/RT. Chemotherapic treatment was ineffective and the patient passed away quickly. In the literature review we found about 300 cases reported, as it is, therefore, extremely rare tumor with a mean age at diagnosis of 29 months. It can affect any area of the central nervous system, mainly infratentorial, being its main differential diagnosis medulloblastomas. The findings of secondary implantation without leptomeningeal spread seen in this patient are described in only one other case in literature. The clinical features usually are neurological deficits, seizures and coma. Its genesis stems from mutations in the gene hSNF5/INI1 on chromosome 22. Neuroimaging studies don?t reveal radiological pattern suggesting AT/RT and the diagnosis is possible only through a biopsy with immunohistochemical analysis. The available treatments are ineffective, and death is the outcome, with 84% in six months. Tumor rabdoide/teratoide atipico de encefalo ? um caso com tres implantes secundarios O tumor rabdoide/teratoide atipico (AT/RT) do encefalo e uma neoplasia pediatrica maligna rara que acomete geralmente criancas ao redor dos dois anos. O caso descrito e de um paciente masculino, de seis meses de idade, que apresentou convulsoes e diminuicao do nivel de consciencia, evoluindo com torpor, paralisia do nervo oculomotor e tetraespasticidade. Exame de tomografia evidenciou neoplasia do ângulo ponto-cerebelar esquerdo. A ressonância magnetica (RNM) demonstrou lesao solida, hipointensa em T1, e heterogenea e hiperintensa em T2, realcada apos contraste, acompanhada de tres lesoes solidas, arredondadas e irregulares no hemisferio cerebelar esquerdo, transicao occipito-parietal direita e lobo occipital direito, sem sinais de disseminacao leptomeningea, constituindo implantes secundarios. Realizou-se entao uma biopsia, que confirmou AT/RT. O tratamento realizado por meio de quimioterapia foi ineficaz e o obito ocorreu rapidamente. Na revisao de literatura encontramos pouco mais de 300 casos descritos, tratando-se, portanto, de neoplasia extremamente rara, com media de idade ao diagnostico de 29 meses. Pode acometer qualquer area do sistema nervoso central, com predominio infratentorial, sendo seu principal diagnostico diferencial os meduloblastomas. Os achados de implantacao secundaria sem disseminacao leptomeningea encontrados neste paciente sao descritos em apenas um outro caso na literatura. O quadro clinico costuma cursar com deficits neurologicos, convulsoes e coma. Sua genese decorre de mutacoes no gene hSNF5/INI1 do cromossomo 22. As neuroimagens nao revelam padrao especifico, sendo o diagnostico possivel somente mediante biopsia com analise imuno-histoquimica. Os tratamentos disponiveis sao ineficazes, e o obito constitui a via final, ocorrendo 84% destes nos primeiros seis meses.