What's in a name: defining pediatric refractory ITP.

There are no agreed upon terminology to define "refractory" pediatric Immune Thrombocytopenia (ITP). Guidelines are therefore limited to arbitrary and outdated definitions. The Pediatric ITP Consortium of North America held a meeting in 2023 to define this entity. With 100% agreement, the faculty established that pediatric ITP that is refractory to emergent therapy could be defined as no platelet response after treatment with all eligible emergent pharmacotherapies. With 100% agreement, the working group established that pediatric patients with ITP that continue to demonstrate high disease burden and/or no platelet response despite treatment with multiple classes of disease modifying therapies represent a challenging subset of ITP. These patients are at higher risk of ongoing disease burden and merit additional investigation as well as consideration for clinical trials or novel therapies. Future efforts to define disease burden and disease response will be completed in collaboration with the ITP International Working Group.

The Evaluation and Management of Methimazole-Induced Agranulocytosis in the Pediatric Patient: A Case Report and Review of the Literature.

INTRODUCTION: Agranulocytosis is a rare, but serious complication of methimazole (MMI) use for Graves' disease (GD). Treatment requires discontinuation of MMI, and the use of propylthiouracil (PTU) is also contraindicated. Few reports exist about the optimal alternative treatment regimens for the management of thyrotoxicosis in these medically complex patients in the pediatric population. CASE REPORT: We report prolonged saturated solution of potassium Iodide (SSKI) use (29 days) in a 17-year-old female with GD and MMI-induced agranulocytosis, who presented with septic shock. Her treatment course also included beta-blockade, cholestyramine, and granulocyte colony stimulating factor. We performed a review of the literature on the use of SSKI in the management of thyrotoxicosis, as well as best practices from the view of endocrinology, infectious disease, hematology, surgery, and intensivists, for the evaluation and management of MMI-induced agranulocytosis. DISCUSSION: The management of MMI-induced agranulocytosis and associated sequelae require subspecialty input and intensive evaluation and monitoring. Alternative treatments to manage hyperthyroidism and control symptoms of thyrotoxicosis during agranulocytosis are a bridge to definitive therapy, and include beta-blockade, SSKI, cholestyramine, steroids, lithium, and plasmapheresis.

Immune thrombocytopenia: A review of upfront treatment strategies.

Immune thrombocytopenia (ITP), resulting from antibody-mediated platelet destruction combined with impaired platelet production, is a rare cause of thrombocytopenia in both children and adults. The decision to treat newly diagnosed patients is based on several factors, including the desire to increase platelet count to prevent bleeding, induce remission, and improve health-related quality of life (HRQoL). At present, standard first-line therapy is corticosteroids. While this treatment does increase the platelet count in many patients, a high percentage still relapse after discontinuation of therapy. For this reason, alteration or intensification of first-line therapy that results in superior long-term remission rates is desirable. The objective of this review is to outline different upfront strategies for newly diagnosed patients with ITP in an effort to potentially enhance remission rates and prevent relapse, taking into account an assessment of the risks and benefits of each approach. We primarily focus on adults with ITP, highlighting pediatric data and practice when applicable.

Malignant Rhabdoid Tumor, an Aggressive Tumor Often Misclassified as Small Cell Variant of Hepatoblastoma.

The clinical management of pediatric liver tumors involves stratification into risk groups. One previously defined, high-risk group of hepatoblastomas is the small cell undifferentiated variant. In light of molecular studies showing SMARCB1 deletion in these tumors, it is now recognized that most small cell, undifferentiated liver tumors represent an aggressive unrelated tumor-the malignant rhabdoid tumor (MRT). SMARCB1 is a member of the chromatin remodeling SWI/SNF complex and encodes the INI1 protein. The histologic diagnosis of MRT is currently based on INI1 negative immunoreactivity and the presence of rhabdoid morphology. INI1-negative small cell liver tumors lacking classic rhabdoid morphology are often misclassified as small cell undifferentiated hepatoblastomas (SCUD-HB), according to the current classification. Pediatric liver tumors diagnosed between 2003-2017 as SCUD-HB (four cases) or MRT (two cases) were identified from the Columbia University Pathology Department Archives. All tumors were associated with normal or low serum alpha fetoprotein levels, and showed an absence of immunohistochemical staining of hepatocellular markers (Hep-par1, Arginase) and loss of INI1 staining. Two cases were initially diagnosed as MRT, one with prominent rhabdoid morphology, the other with predominant small cell morphology. The remaining four cases with small cell morphology were classified as SCUD-HB. Ancillary molecular studies confirmed the loss of SMARCB1, supporting the diagnosis of MRT in all cases, proving morphology an unreliable criterion. It is critical to eliminate the term INI1-negative hepatoblastoma from the current classification scheme, and classify INI1-negative tumors as MRT, particularly since high-risk HB-chemotherapy regimens are not effective for treating MRT.