Secondary Hemophagocytic Lymphohistiocytosis in a Patient With Favorable Histology Wilms Tumor.

Secondary hemophagocytic lymphohistiocytosis (HLH) is most commonly associated with malignancy, infection, or an underlying autoimmune disorder. Malignancy-associated hemophagocytic syndrome is responsible for most secondary HLH cases, but it has not been well described in children. We present a case of a 4-year-old female with favorable histology of Wilms tumor who developed secondary HLH after unsuccessful resection of the tumor and initiation of chemotherapy.

Glioblastoma multiforme arising from dysembryoplastic neuroepithelial tumor in a child in the absence of therapy.

Dysembryoplastic neuroepithelial tumors (DNETs) are considered as low-grade tumors commonly associated with intractable seizures. We report a case of an unusual hemispheric DNET in a young child presenting with new-onset focal seizures. The tumor was notable for its atypical neuroimaging features and very rapid malignant transformation into a glioblastoma multiforme in the absence of radiation or chemotherapy, 1-year postdiagnosis. Our case highlights the malignant potential of atypical DNETs in the absence of therapy.

Anti-tumor activity of the HSP90 inhibitor SNX-2112 in pediatric cancer cell lines.

BACKGROUND: HSP90 plays a central role in stabilizing client proteins involved in malignant processes. SNX-2112 is an orally administered potent HSP90 inhibitor that has demonstrated pre-clinical anti-tumor activity in adult malignancies. As many childhood tumors depend upon HSP90 client proteins, we sought to test the pre-clinical efficacy of SNX-2112 in a panel of pediatric cancer cell lines both as a single-agent and in combination with cisplatin (CP). PROCEDURE: Eight cell lines (from osteosarcoma, neuroblastoma, hepatoblastoma, and lymphoma) were studied. Short- and long-term effects of SNX-2112 were assessed by MTT and clonogenic assays. Cell cycling was measured using flow cytometry. Status of HSC70, HSP72, AKT1, C-Raf, and PARP was assessed by immunoblotting. Efficacy of SNX-2112 in combination with CP was assessed using median-effect analysis. RESULTS: Cell lines studied demonstrated sensitivity to SNX-2112 with IC(50) values ranging from 10-100 nM. Low dose treatments (12 nM) resulted in a cytostatic response with a minimal increase in sub-G1 content. A higher dose (70 nM) exhibited a more prolonged inhibition and larger sub-G1 accumulation. Observed levels of AKT1 and C-Raf were markedly reduced over time along with an increase in PARP cleavage. In concurrently administered combination treatments, SNX-2112 and CP synergistically inhibited cell growth. CONCLUSIONS: SNX-2112 showed marked single-agent activity in pediatric cancer cell lines with downstream effects on HSP90 client proteins. The combination of SNX-2112 and CP showed synergistic activity in two cell lines tested. Further studies of HSP90 inhibitors such as SNX-2112 as a single agent or in combination with chemotherapy are warranted in pediatric cancer.

A novel mutation in a Fijian boy with Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic insufficiency, bone marrow dysfunction, and metaphyseal chondrodysplasia. SDS is associated with mutations in the Shwachman-Bodian-Diamond Syndrome gene, with 90% of reported mutations in exon 2. We present a Fijian boy with SDS who has a novel A>G substitution in exon 1 of the Shwachman-Bodian-Diamond Syndrome gene that has not been reported in the literature. This patient's unique clinical course includes the presence of a cleft lip and episodic hypoglycemia. SDS lacks a clear genotype-phenotype correlation, as is showed by the heterogeneity in its clinical presentation.

Severe vincristine-induced polyneuropathy in a teenager with anaplastic medulloblastoma and undiagnosed Charcot-Marie-Tooth disease.

Severe neuropathy is a known adverse effect of vincristine in patients with Charcot-Marie-Tooth disease (CMT). We present the case of a 16-year-old girl with anaplastic medulloblastoma treated with gross total resection and high-dose craniospinal radiation with adjuvant vincristine chemotherapy who developed acute-onset severe quadriplegia and vocal cord paralysis. Vincristine and radiation therapy were discontinued. Although her neuropathy slowly improved over several weeks, she developed metastatic extraneural medulloblastoma and died 5 months after diagnosis. Subsequent genetic testing revealed previously asymptomatic and undiagnosed CMT1A. Our case highlights the importance of early recognition of acute vincristine neurotoxicity that should raise suspicion of an underlying hereditary neuropathy.

Atypical Teratoid Rhabdoid Tumor in a Teenager with Unusual Infiltration Into the Jugular Foramen.

BACKGROUND: Atypical teratoid rhabdoid tumor is a rare malignant neoplasm that represents 1%-2% of all pediatric central nervous system tumors. Immunohistochemistry plays an important role in establishing the diagnosis with a loss of INI-1 staining in tumor cells. In this case report, we describe a teenager with an unusual presentation and pattern of infiltration of the tumor. CASE DESCRIPTION: A 13-year-old boy presented with a history over several months of progressive nausea, weight loss, and hoarseness of voice associated with multiple lower cranial nerve palsies on neurologic examination. Magnetic resonance imaging revealed a large heterogeneously enhancing extra-axial neoplasm with extension and bony expansion of the jugular foramen. After near total resection, neuropathology demonstrated the absence of INI-1 expression consistent with a diagnosis of atypical teratoid rhabdoid tumor. CONCLUSIONS: This case highlights the diverse clinical presentation and infiltrative potential of atypical teratoid rhabdoid tumors, thus expanding the differential diagnosis of extra-axial tumors invading the jugular foramen.

Treatment of infantile choriocarcinoma of the liver.

Primary choriocarcinoma of the liver is an extremely rare childhood malignancy frequently associated with clinical instability at initial presentation. It often mimics other benign and malignant childhood liver tumors. Prompt diagnosis and initiation of treatment are necessary to attain a successful outcome. We describe a critically ill infant with metastatic choriocarcinoma whose diagnosis was based on radiographic and tumor marker findings, without an initial biopsy, and her successful management with neo-adjuvant chemotherapy and delayed surgery. She is currently in continuous remission 24 months from diagnosis.

Modifying the soil to affect the seed: role of stromal-derived matrix metalloproteinases in cancer progression.

In the 1980's, as the importance of matrix metalloproteinases (MMPs) in cancer progression was discovered, it was recognized that in most tumors these proteases were abundantly and sometimes exclusively expressed not by tumor cells, but by normal host-derived cells like fibroblasts, vascular endothelial cells, myofibroblasts, pericytes or inflammatory cells that contribute to the tumor microenvironment. Later experiments in mice deficient in specific MMPs revealed that host-derived MMPs play a critical role not only in tumor cell invasion, but also in carcinogenesis, angiogenesis, vasculogenesis and metastasis. Tumor cells secrete many factors, cytokines and chemokines that directly or indirectly increase the expression of these MMPs in the tumor microenvironment where they exert extracellular matrix (ECM) degrading and sheddase activities. The knowledge of the complex role that stromal-derived MMPs play in the interaction between tumor cells and stromal cells should allow us to consider specific windows in cancer treatment when MMP inhibition could have a valuable therapeutic effect.