SummaryStudies using Fanconi anaemia (FA) mutant mouse models suggested that the combination of a defective FA pathway and aldehyde dehydrogenase-2 (ALDH2) dysfunction could provoke bone marrow failure, leukaemia and developmental defects, and that both maternal and fetal aldehyde detoxification are crucial to protect the developing embryo from DNA damage. We studied the ALDH2 genotypes of 35 Japanese FA patients and their mothers. We found that a normal maternal ALDH2 allele was not essential for fetal development of ALDH2-deficient patients, and none of the post-natal clinical parameters were clearly affected by the maternal ALDH2 genotype in these patients.

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition resulting from an uncontrolled and ineffective immune response. Here, we report a case of HLH caused by disseminated herpes simplex virus (HSV)-1 infection. The patient was initially treated with prednisolone and high-dose acyclovir. Although liver enzymes, coagulation abnormalities, and inflammatory markers were remarkably improved, the platelet count remained low. Prednisolone was therefore switched to dexamethasone palmitate. Thereafter, the platelet count normalized. Inflammatory markers normalized 30 days after admission and serum HSV-DNA became undetectable on day 41. The patient was discharged on day 91 and no developmental delay was evident at 7 months of age. These findings suggest that dexamethasone palmitate is effective for neonatal HLH.

A 5-year-old girl noticed a rapidly growing reddish nodule on her right forearm. Although oral antibiotics had been administrated for 2 weeks, the tumor enlarged. Skin biopsy revealed excessive infiltration of atypical neoplastic cells expressing CD4, CD30 and anaplastic lymphoma kinase (ALK). These histological and immunohistochemical findings were consistent with anaplastic large cell lymphoma (ALCL). Computed tomography showed multiple lymphadenopathy, but lymph node biopsy and bone marrow examination did not show any evidence of systemic dissemination. However, due to the positive results for ALK and multiple lymphadenopathy, we diagnosed ALK-positive ALCL forming a solitary skin tumor on the forearm. The patient received chemotherapy and presented marked improvement. This paper discusses the difficulty of diagnosing pediatric ALK-positive ALCL limited to the skin and reviews the medical published work.

L-asparaginase (L-asp) is a well-known anticancer agent used in the treatment of acute lymphoblastic leukemia (ALL) in children. However, it is also known to induce several acute complications, such as acute pancreatitis. This is a presentation of two pediatric acute lymphoblastic leukemia (ALL) cases of asparaginase-associated pancreatitis (AAP) diagnosed at an early stage based on elevated serum elastase-1 levels, in the presence of normal serum amylase levels. Early diagnosis and treatment of AAP, although imperative, is occasionally difficult if only standard diagnostic procedures are followed. Elastase-1 is a potentially useful marker for the early diagnosis of AAP. Therefore, the measurement of elastase-1 levels, in addition to amylase and lipase levels, is recommended in L-asp-treated patients.

Mixed-phenotype acute leukemia (MPAL) is a rare type of leukemia expressing both myeloid and lymphoid markers. There is limited information, especially on pediatric cases. Therefore, the optimal therapeutic approach to pediatric MPAL has not been defined. Here, we report two pediatric cases of MPAL. According to the 2008 World Health Organization (WHO) classification and European Group for the Immunological Characterization of Leukemias (EGIL) criteria, patient 1 was diagnosed with overt MPAL positive for the myeloid marker myeloperoxidase (MPO), and B-lymphoid markers. Patient 2 was diagnosed with T-cell acute lymphoblastic leukemia (T-ALL) using EGIL criteria. According to the 2008 WHO classification, however, patient 2 was diagnosed with overt MPAL positive for CD3, T-lymphoid markers and MPO. We chose an ALL-type therapy consisting of both lymphoid- and myeloid-directed agents; these patients have maintained complete remission following treatment. Further information on pediatric MPAL is needed to establish an appropriate therapeutic strategy including stem cell transplantation for this rare condition.