Treatment for primary spinal atypical teratoid/rhabdoid tumor

Clinical diagnostic and radiographic features of primary spinal atypical teratoid rhabdoid tumors tumor in a pediatric patient: A case report and review of the literature

Atypical teratoid rhabdoid tumors (ATRTs) are rare embryonal tumors comprising 1-2% of all pediatric CNS neoplasms. Spinal ATRTs are even more uncommon, accounting for 2% of all reported ATRT cases. Despite their rarity, ATRTs affect young children disproportionately and are characterized by a high malignant potential due to a heterogeneous cellular composition and inactivating mutations in the SMARCB1 (90%) and SMARCA4 (10%) genes. A 15-month-old female presented with a 2-week history of decreased lower extremity movement and new-onset need for assistance with ambulation. MRI lumbar spine revealed a contrast-enhancing intradural mass at the L3-L4 level with iso-intensity on T1 and T2 sequences. The patient subsequently underwent subtotal tumor resection (∼80%) given concerns for maintaining neurological function. Final pathology was consistent with spinal ATRT, and she later underwent adjuvant chemoradiation therapy per ACNS0333 protocol. She has since remained in remission with age-appropriate developmental milestones over the past 2 years. ATRTs should be considered in the differential diagnosis of intradural spinal lesions, especially in the pediatric patient population. Clinical course, presentation, and diagnosis is often delayed due to the rarity of these tumors, but contrasted craniospinal MRI is key for diagnosis and histopathology with IHC staining showing loss of INI is confirmatory. While gross total resection is the goal, maximal safe tumor resection should be prioritized in order to preserve neurological function. Adjuvant chemoradiation following gross total/subtotal resection has been shown to significantly improve overall survival.

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 × 1.5 × 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.

Atypical Teratoid/Rhabdoid Tumor of the Conus Medullaris

INTRODUCTION

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor of the central nervous system, especially when involving the spinal column or spinal cord.

CASE PRESENTATION

We present a case of a 5-year-old girl with progressive bilateral lower extremity pain found to have a discrete nodular lesion of the conus with mild heterogeneous enhancement. Surgical decompression and resection demonstrated a pathologic tumor consistent with AT/RT with loss of INI1 protein on immunohistochemistry.

DISCUSSION AND CONCLUSION

AT/RT lesions of the conus medullaris are exceedingly rare and associated with extensive disease. We report a rare case of AT/RT with selective involvement of the conus medullaris, as well as describe the surgical, radiographic, and pathologic findings of this tumor.

Pediatric primary spinal atypical teratoid rhabdoid tumor: a case series and review of the literature

Atypical teratoid rhabdoid tumors (ATRTs) are rare malignant central nervous system tumors, commonly occurring before 3 years of age. Median overall survival (OS) of patients with these tumors is about 1 year, despite aggressive multimodal therapy. Pediatric primary spinal ATRTs are even more rare, with fewer than 50 cases reported. The authors present a series of four patients who were treated at Ann and Robert H. Lurie Children's Hospital of Chicago in the period from 1996 to 2017.These patients, with ages 2-11 years, presented with pain and a decline in motor functions. They were found to have lesions in the lumbar, thoracic, and/or cervical spine. One patient's tumor was intramedullary with exophytic components, while another patient's tumor had both intra- and extradural components. All patients underwent resection followed by chemotherapy (systemic and intrathecal). Two patients had fractionated radiation therapy and one had an autologous stem cell transplant. Three patients are known to be deceased (OS 8.5-45 months). The fourth patient was in remission 19 years after her initial diagnosis. To the authors' knowledge, this is the largest series of pediatric primary spinal ATRTs documented at a single institution. These cases illustrate a variety of presentations of spinal ATRT and add to the body of literature on this aggressive pathology.A systematic MEDLINE search was also conducted using the keywords "atypical teratoid rhabdoid tumor," "pediatric spinal rhabdoid tumor," and "malignant rhabdoid tumor spine." Reports were included for patients younger than 21 years, without evidence of intracranial or systemic disease at the time of diagnosis. Clinical characteristics and outcomes of the four institutional cases were compared to those in the literature. This review yielded an additional 48 cases of primary pediatric spinal ATRTs reported in the English-language literature. Patients (ages 2 months to 19 years) presented with symptoms of pain, regression of motor function, and spinal cord compression. The majority of tumors were intradural (14 extramedullary, 8 intramedullary, 1 both). Eleven cases in the literature described tumors limited to extradural structures, while 10 tumors involved the intra- and extradural spine. Four reports did not specify tumor location. Although rare, spinal ATRT should be considered in the differential diagnosis of pediatric patients presenting with a new spinal mass.