Successful Multimodality Management Of Atypical Teratoid/Rhabdoid Tumour Of The Lower Dorsal Spine With Spinal Drop Metastasis: Illustrated Review

Introduction: Spinal atypical teratoid/rhabdoid tumour (AT/RT) is exquisitely rare and constitutes 2% of all AT/RTs. Case Presentation: A 6-year-old boy presented with low backache for the last 5 months. MRI of the spine showed a 1.5 x 1.5 x 4.7 cm intradural extramedullary mass extending from D10 to D12, causing compression of the conus medullaris. With a preoperative diagnosis of ependymoma, a gross total resection (GTR) of tumour was performed. Post-operative histopathology showed AT/RT. The tumour cells were immunopositive for cytokeratin, epithelial membrane antigen, smooth muscle actin, and p53 and immunonegative for MIC2, desmin, glial fibrillary acidic protein, and INI1. Post-operative neuraxis MRI revealed post-operative changes (D10-D12) with a 9 mm enhancing lesion at L5-S1 junction suggesting drop metastasis. There was no lesion in brain. Cerebrospinal fluid cytology did not show any malignant cell. The metastatic work-up was normal. He received 3 cycles of chemotherapy with ICE regimen (ifosfamide, carboplatin, and etoposide). Subsequently, he received craniospinal irradiation (CSI)-36 Gy/20 fractions/4 weeks followed by focal boost to primary tumour bed and spinal drop metastasis-14.4 Gy/8 fractions/1.5 weeks. Thereafter, he received 3 more cycles of ICE regimen. End-of-treatment MRI spine showed post-op changes (D10-D12) and 38.9% reduction of the L5-S1 lesion suggesting partial response. Six monthly spinal MRI showed serial reduction of the metastatic lesion leading to complete response (CR) 1 year after completion of treatment. On last follow-up (30 months from the initial diagnosis), he was neurologically intact and in CR. Conclusion: Multimodality management comprising GTR of tumour, CSI followed by focal boost, and multiagent chemotherapy (ICE) can lead to successful outcome in patients with this rare and aggressive spinal tumour.