Extrarenal malignant rhabdoid tumor infiltrating the brachial plexus and spinal canal

Abstract

Extrarenal malignant rhabdoid tumors are rare, aggressive lesions that primarily affect infants and children with characteristic SMARCB1/INI1 mutations. While rhabdoid tumors are most commonly found in the kidneys and central nervous system, they have been reported in virtually every soft tissue in the body. A 20-year-old previously healthy male presented with a 4-month history of left upper extremity weakness and pain and a 1-week history of lower extremity weakness. MRI showed a combined intradural and extradural mass arising from the C8 root and involving the lower trunk of the brachial plexus. CT guided biopsy followed with onsite cytologic analysis initially concerning for plasma cell etiology. Full body PET/CT showed no evidence of metastases. The tumor was surgically resected and debulked. Extensive immunohistochemical testing on the resected specimen revealed a diagnosis of extrarenal malignant rhabdoid tumor. Recurrence invading paraspinous muscles, left lateral paravertebral space, left apical lung, and brachial plexus was noted within 2 months. Radiation and chemotherapy were initiated. Here we present imaging findings, image-guided biopsy, surgical management, and pathologic diagnosis of a rare case of extrarenal, extracranial malignant rhabdoid tumor of the brachial plexus and surrounding paraspinous muscles in a young adult male.

Oncologia e Hematologia - Edição VI

“…Outrossim, é possível observar na literatura casos mais raros que estão intrinsecamente relacionados ao diagnóstico maligno no plexo braquial, é o caso por exemplo, do tumor rabdóide maligno, esses tumores são considerados extremamente raros, representando menos de 1% tanto dos sarcomas infantis quanto dos sarcomas de tecidos moles, com aproximadamente 15 novos casos diagnosticados nos Estados Unidos a cada ano. A incidência em adultos é ainda mais incomum (SANT et al, 2022).…”

“…Embora mais comumente encontrados nos rins e no sistema nervoso central, os tumores rabdóides malignos foram documentados em praticamente todos os tecidos moles do corpo, incluindo pele, fígado, pulmão, pescoço, bexiga, coração, ovário, retroperitônio, mediastino e músculos paravertebrais (SANT et al, 2022). Essa ampla distribuição, apesar da raridade, destaca a complexidade desses tumores e a dificuldade no diagnóstico e tratamento.…”