Aiko Kozaki

Prevention of chemotherapy-induced vomiting in children receiving multiple-day cisplatin chemotherapy: A hospital-based, retrospective cohort study: Kishimoto et al.

Optimal prevention of chemotherapy‐induced vomiting (CIV) has not been established for patients receiving cisplatin in divided doses. The aim of this study was to describe the incidence and risk factors of CIV in children who received multiple‐day cisplatin chemotherapy.

Low-dose azacitidine maintenance therapy after allogeneic stem cell transplantation for high-risk pediatric acute myeloid leukemia

The dismal prognosis of pediatric acute myeloid leukemia (AML) relapsing after hematopoietic stem cell transplantation (HSCT) requires exploration of novel strategies to prevent relapse. Azacitidine (AZA) maintenance therapy could potentially reduce the recurrence rate post HSCT. Here, we presents the cases of three children with high‐risk AML post HSCT who were treated with low‐dose AZA maintenance therapy, demonstrating the feasibility of this therapy. Currently, all three are in complete remission for 13–41 months despite their high‐risk characteristics. Our encouraging data warrant larger prospective studies to assess the efficacy and safety of low‐dose AZA maintenance therapy post HSCT for pediatric patients with high‐risk AML.

Successful Treatment of Transplantation-associated Atypical Hemolytic Uremic Syndrome With Eculizumab

We herein reported a 4-month-old boy with transplantation-associated atypical hemolytic uremic syndrome (TA-aHUS) who was successfully treated with eculizumab. The patient diagnosed with type 3 of familial hemophagocytic lymphohistiocytosis underwent cord blood transplantation. After transplantation, he developed TA-aHUS, but plasma exchanges were unsuccessful. We identified deletions in CFH-related gene 1 (del-CFHR1) by the multiplex ligation-dependent probe amplification testing procedure and CFH autoantibodies. Eculizumab has been administered to the patient, with a marked improvement being achieved in thrombocytopenia. He has been well except for the persistent microhematuria for a year after transplantation. Uncontrolled complement activation might be involved in the pathophysiology of TA-aHUS.

Reemergence of translocation t(11;19)(q23;p13.1) in the absence of clinically overt leukemia

We report the case of a 10-year-old female with acute myeloid leukemia (AML) FAB M0 carrying a novel t(11;19)(q23;p13.1) MLL–ELL variant, in which intron 8 of MLL is fused to exon 6 of ELL. Complete remission, judged by morphology and cytogenetic analysis, was achieved after the conventional chemotherapy. Eight months after completion of therapy, the level of WT-1 in peripheral blood and the number of cells with the MLL–ELL fusion transcript resurged. However, the patient remained overtly healthy and the morphology in the bone-marrow smear was innocuous, with no sign of relapse or secondary leukemia. Without any evidence of relapse, the patient has been closely observed without any therapeutic intervention. For approximately 2 years after the completion of therapy, despite clonal proliferation of pre-leukemic cells with an MLL–ELL fusion gene, she has maintained complete remission. In this case, the rare variant form of MLL–ELL fusion that has been identified may be related to diminished leukemogenic capacity, resulting in the persistence of pre-leukemic status; an additional genetic abnormality may thus be necessary for full transformation of pre-leukemic cells.

Successful non-myeloablative allogenic bone marrow transplantation in a child with severe congenital neutropenia complicated by chronic pulmonary infection.

We herein describe a 2-year-old boy with severe congenital neutropenia (SCN) who was successfully treated with reduced-intensity bone marrow transplantation (HSCT). He had suffered recurrent episodes of bacterial pneumonia from 12 months of age, and was found to have severe neutropenia with white blood cell counts below 100/μl. The patient harbored a heterozygous missense mutation in ELANE exon 4 (p.Gln134Pro, NM_001972.2: c.401A>C). This was a novel mutation. Due to intractable pneumonia and severe persistent neutropenia, reduced-intensity HSCT was performed from an HLA-matched sibling donor. The preparative regimen consisted of melphalan, fludarabine, and 4 Gy of total body irradiation. Hematopoietic engraftment was rapidly obtained, i.e., by day +14, and complete donor chimerism was subsequently achieved. The lung complications observed pre-transplantation markedly improved after neutrophil recovery, i.e., by day +60. We concluded that HSCT is a useful treatment for SCN patients, especially for those at high risk of leukemic transformation. Fludarabine-based reduced-intensity HSCT may represent a safe and effective therapeutic option for patients with SCN who need HSCT even if they have intractable infectious complications.

Congenital mesoblastic nephroma with focal anaplastic lesion

To the Editor: Congenital mesoblastic nephroma (CMN) is a rare renal tumor that comprises spindle cells and most often arises in newborns and infants. CMNs are classified into three types: cellular, classic, and mixed type. Cellular type CMN expresses the same chimeric protein ETV6-NTRK3 as does infantile fibrosarcoma and is therefore regarded as infantile fibrosarcoma within the kidney. Pathologically, cellular type CMN is sometimes difficult to distinguish from clear cell sarcoma of the kidney (CCSK) because CCSK is also a childhood, renal, mesenchymal tumor. However, differentiating cellular type CMN from CCSK is clinically important because therapy after nephrectomy and prognosis differ greatly between these cancers. CCSKs display several variations of histological patterns, and an anaplastic pattern is seen in approximately 2.6% of primary and recurrent CCSKs. To our knowledge, no cellular type CMN or infantile fibrosarcoma with an anaplastic pattern has been reported. Here, we describe a renal spindle cell tumor with focal anaplastic lesion in a pediatric patient. The presence of focal anaplastic lesion made diagnosis of CMN difficult, and verifying expression of the oncogenic ETV6-NTRK3 fusion was the key to accurately diagnosing cellular type CMN. This case demonstrates that focal anaplastic lesion may be seen in cellular type CMN. The patient was a boy aged one year and five months. His family noticed abdominal enlargement when he was 1 year old, but did not consider the condition serious because his abdomen was soft and he was afebrile and not vomiting. However, his abdomen gradually became harder and more enlarged. He was admitted to our hospital at the age of 1 year and 5 months. A right renal tumor measuring 9 × 12 cm with necrosis was found on abdominal enhanced computed tomography. No distant metastasis, lymphadenopathy, or tumor infiltration into the inferior vena cava was detected. Right nephrectomy was performed. The right kidney was resected with the right ureter and right adrenal gland; this complex weighed 1.1 kg and measured 15 × 12 × 12 cm. No rupture of the capsule was evident. On cut section, the tumor was soft and displayed variegated color with the dark red of hemorrhage and the brown of necrosis in the center and a white-yellow color at the margins. The tumor was fairly well demarcated. Samples for reverse transcriptase-polymerase chain reaction (RT-PCR) were taken from the white-yellow peripheral part of the tumor. On microscopic examination, the tumor margin was sharply and linearly demarcated or had infiltrated only a short distance into the renal parenchyma with a pushing border. The tumor was within the kidney and had not invaded into the renal capsule. No invasion into the renal pelvis or adipose tissue in the renal sinus was found. The cut ends of the ureter and the renal artery and vein were tumor-negative. An old hematoma and wide necrosis were centered within the tumor, and microscopic necrotic foci were scattered within the tumor. The tumor entrapped isolated renal tubules or glomeruli. The tumor comprised interlacing fascicles of spindle cells with bipolar cytoplasmic processes and round to slightly elongated nuclei containing fine chromatin and a few (1 or 2) tiny nucleoli (Fig. 1a). A storiform pattern of cells was observed. Mitotic counts per one high-power field (HPF) were 1 to 7 (mean approximately 4), but karyorrhexis was more frequent than mitosis. Cells with bizarre giant nuclei or with multiple nuclei and with abundant eosinophilic cytoplasm were found in the sharply demarcated nodular region that measured 4 × 2 mm (Fig. 1b). Multipolar mitotic figures were also observed in this region. So these cells fulfill the criteria of anaplasia defined for nephroblastoma, CCSK, and anaplastic sarcoma of the kidney (ASK). There were no transitional features between the anaplastic lesion and the surrounding