High-dose carboplatin-irinotecan-temozolomide is an effective salvage chemotherapy for relapsed or refractory neuroblastoma.

There is no clear consensus on the most effective treatment for relapsed/refractory high-risk neuroblastoma (NB). We retrospectively assessed seven NB patients with relapsed/refractory disease who received high-dose carboplatin-irinotecan-temozolomide (HD-CIT). Five of seven patients showed favorable therapeutic response (complete remission or partial remission). Regarding toxicity, the cytopenia period tended to prolong when more than three cycles were repeated, but nonhematological toxicities were controllable with general supportive care. Due to its antitumor efficacy and well-tolerated nonhematologic toxicity, HD-CIT is a promising salvage chemotherapy for relapsed/refractory NB. However, it is important to pay attention to the exacerbation of hematological toxicity when repeating the regimen.

PAX5 alterations in an infant case of KMT2A-rearranged leukemia with lineage switch.

Lineage switch is a rare event at leukemic relapse. While mostly known to occur in KMT2A-rearranged infant leukemia, the underlying mechanism is yet to be depicted. This case report describes a female infant who achieved remission of KMT2A-MLLT3-rearranged acute monocytic leukemia, but 6 months thereafter, relapsed as KMT2A-MLLT3-rearranged acute lymphocytic leukemia. Whole exome sequencing of the bone marrow obtained pre-post lineage switch revealed two somatic mutations of PAX5 in the relapse sample. These two PAX5 alterations were suggested to be loss of function, thus to have played the driver role in the lineage switch from acute monocytic leukemia to acute lymphocytic leukemia.

[Haploidentical stem cell transplantation for acute myeloid leukemia associated with adult-onset Shwachman-Diamond syndrome].

A 21-year-old man presented with bone marrow failure, short stature, fatty degeneration of the pancreas on CT images, and Shwachman-Bodian-Diamond syndrome (SBDS) gene abnormalities (exon 2: c.258+2T>C and deletion of exon 3). Thus, the patient was diagnosed with Shwachman-Diamond syndrome (SDS). In the clinical course, the patient developed acute myeloid leukemia (AML). Hematopoietic stem cell transplantation from the human-leukocytic-antigen-haploidentical father of the patient was performed. The patient was conditioned with 150 mg/m2 fludarabine, 6.4 mg/kg busulfan, and 4 Gy total body irradiation. Graft-versus-host disease prophylaxis included tacrolimus, micophenolate mofetil, and posttransplant cyclophosphamide. Although the patient achieved a complete remission on day 21, AML relapsed on day 434 after the transplantation. He died of sepsis. The prognosis of patients with SDS and AML is poor. Adult-onset cases must be recognized, and transplantation should be performed during bone marrow failure.

The clinical utility of genetic testing for t(8;16)(p11;p13) in congenital acute myeloid leukemia.

Acute myeloid leukemia (AML) with t(8;16)(p11;p13) is known to have very poor prognosis in adults. In contrast, the prognosis is not clear in pediatric patients and chemotherapy is generally started immediately in cases of congenital leukemia because of its association with hyperleukocytosis and poor prognosis. This study reports a case of congenital AML where chemotherapy was discontinued after detection of a MOZ-CBP fusion, which remains in remission without additional treatment. This article stresses the importance of examination for the presence of the MOZ-CBP fusion at diagnosis to inform treatment decisions in congenital AML.