Atypical teratoid/rhabdoid tumors (AT/RT) rarely occur in the cauda equina; thus, the clinical behavior and optimal treatment remain unclear. A 9-year-old boy presented with a rapidly progressing intradural extramedullary tumor at the L2–5 level, underwent tumor resection, and was diagnosed with AT/RT. His gait disturbance improved postoperatively, and he received adjuvant chemotherapy and radiotherapy. In 5 months of follow-up, recurrence was not observed. Although extremely rare, AT/RT should be included in the differential diagnosis, as it requires prompt therapeutic intervention. Safe resection with minimal functional impairment, followed by postoperative chemoradiation, can lead to tumor control and improve neurological function.

Background: Although conservative treatment has been used for unilateral retinoblastoma, enucleation is still the mainstay of treatment for the ICRB D–E group. In Japan, conservative treatment has been performed to preserve the eyes of patients with unilateral retinoblastoma including group D–E. We analyzed the data of patients treated at our institution with the aim of assessing if conservative therapy in the D–E group would worsen the survival outcomes and if it would also enable preservation of visual acuity. Procedure: We retrospectively reviewed medical records of patients of unilateral retinoblastoma from January 1, 2006, to December 31, 2015. Survival rates, EBRT-avoided preservation rates, and safety were analyzed for the initially enucleated and conservative treatment groups. Results: Among 153 patients, 34 (89%) in the B–C group and 49 (43%) in the D–E group underwent conservative treatment, respectively. 36 out of 83 (43%) patients were able to avoid enucleation without EBRT by undergoing conservative treatment. In the D–E groups with conservative treatment, there were extraocular recurrences in two patients, and one patient who had a CNS recurrence died. The 5-year OS and RFS was 97.9 (95%CI : 85.8–99.7)% and 95.8 (95%CI : 84.3–98.9)% in the D–E group, respectively. There were no acute serious adverse events during conservative treatment, and no secondary malignancies were observed. Conclusion: Conservative treatment for unilateral retinoblastoma, including for the D–E groups is acceptable based on the results that OS remained high and no serious adverse events were observed.

Background: In children with intermediate-risk relapsed acute lymphoblastic leukemia (ALL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) has markedly improved the outcome of patients with poor minimal residual disease (MRD) response. However, there is no consensus on the optimal conditioning regimen for allo-HSCT. Procedure: We prospectively analyzed the efficacy and safety of allo-HSCT with a unified conditioning regimen for children with intermediate-risk relapsed ALL, based on MRD in the bone marrow after induction, in the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) ALL-R08-II nationwide cohort. The conditioning regimen for allo-HSCT comprised total body irradiation (TBI), etoposide (ETP) and cyclophosphamide (CY) (UMIN000002025). Results: Twenty patients with post-induction MRD ≥ 10 −3 and two with MRD that could not be evaluated underwent allo-HSCT. Engraftment was confirmed in all patients. No transplantation-related mortality was observed. The 3-year event-free survival and overall survival after transplantation were 86.4% ± 7.3% and 95.5% ± 4.4%, respectively. Conclusion: Allo-HSCT based on post-induction MRD with TBI + ETP + CY conditioning was highly effective and feasible for Japanese children with intermediate-risk relapsed ALL.