Prevention of mercaptopurine‐induced hypoglycemia using allopurinol to reduce methylated thiopurine metabolites

Skewing of mercaptopurine (6‐MP) metabolism preferentially toward the 6‐methylmercaptopurine (6‐MMP) metabolite over the antileukemic metabolite 6‐thioguanine (6‐TGN) is associated with 6‐MP‐related hepatotoxocity. Allopurinol when coadministered with 6‐MP can reduce this skewing and ameliorate the associated adverse effects. The cases we report here demonstrate that aberrant overproduction of 6‐MMP is also associated with profound 6‐MP‐associated hypoglycemia, which can be reversed by administration of allopurinol. This case series contributes to the scant literature on 6‐MP‐induced hypoglycemia and provides evidence that addition of allopurinol to reduced dose 6‐MP can successfully manage this severe toxicity.     

Treatment response with sirolimus for a pediatric patient with an EBV‐associated smooth‐muscle tumor after bone marrow transplantation

Epstein–Barr virus–associated smooth‐muscle tumors (EBV‐SMTs) are unique and rare neoplasms described in immunocompromised patients. The case describes a nine‐year‐old female with a history of acute lymphoblastic leukemia with relapse and subsequent allogeneic bone marrow transplantation who presented with multiple EBV‐SMTs of the liver. EBV utilizes the mammalian target of rapamycin (mTOR) pathway for tumor growth, and sirolimus, a mTOR inhibitor, has shown to result in a short‐term response. We now report an extended treatment response with sirolimus in a pediatric patient with an EBV‐SMT.     

Defining an optimal time window to screen for hepatoblastoma in children with Beckwith‐Wiedemann syndrome

Patients with Beckwith‐Wiedemann spectrum (BWSp) undergo quarterly alpha‐fetoprotein measurement for hepatoblastoma (HB) screening up to 4 years of age, paralleling the epidemiology of nonsyndromic HB. However, specific data on the timing of HB development in BWSp are lacking. Here we compare the timing of presentation of HBs in BWSp with a control cohort of consecutive HB cases, demonstrating that halving screening duration of screening procedures in BWSp likely will not impact its effectiveness.