Samir B. Kahwash

Gemtuzumab Ozogamicin in Children and Adolescents With De Novo Acute Myeloid Leukemia Improves Event-Free Survival by Reducing Relapse Risk: Results From the Randomized Phase III Children's Oncology Group Trial AAML0531

PURPOSE To improve survival rates in children with acute myeloid leukemia (AML), we evaluated gemtuzumab-ozogamicin (GO), a humanized immunoconjugate targeted against CD33, as an alternative to further chemotherapy dose escalation. Our primary objective was to determine whether adding GO to standard chemotherapy improved event-free survival (EFS) and overall survival (OS) in children with newly diagnosed AML. Our secondary objectives examined outcomes by risk group and method of intensification. PATIENTS AND METHODS Children, adolescents, and young adults ages 0 to 29 years with newly diagnosed AML were enrolled onto Children’s Oncology Group trial AAML0531 and then were randomly assigned to either standard five-course chemotherapy alone or to the same chemotherapy with two doses of GO (3 mg/m2/dose) administered once in induction course 1 and once in intensification course 2 (two of three). RESULTS There were 1,022 evaluable patients enrolled. GO significantly improved EFS (3 years: 53.1% v. 46.9%; hazard ratio [HzR], 0.83; 95% CI, 0.70 to 0.99; P.04) but not OS (3 years: 69.4% v. 65.4%; HzR, 0.91; 95% CI, 0.74 to 1.13; P = .39). Although remission was not improved (88% v. 85%; P = .15), posthoc analyses found relapse risk (RR) was significantly reduced among GO recipients overall (3 years: 32.8% v. 41.3%; HzR, 0.73; 95% CI, 0.58 to 0.91; P = .006). Despite an increased postremission toxic mortality (3 years: 6.6% v. 4.1%; HzR, 1.69; 95% CI, 0.93 to 3.08; P = .09), disease-free survival was better among GO recipients (3 years: 60.6% v. 54.7%; HzR, 0.82; 95% CI, 0.67 to 1.02; P = .07). CONCLUSION GO added to chemotherapy improved EFS through a reduction in RR for children and adolescents with AML.

Pediatric eosinophilic esophagitis: radiologic findings with pathologic correlation

BackgroundEosinophilic esophagitis is increasingly recognized as a cause of dysphagia or food impaction in pediatric patients. It has a high male predominance and is often associated with a history of allergy or asthma.ObjectiveTo correlate fluoroscopic findings in eosinophilic esophagitis with the endoscopic and histologic findings.Materials and methodsWe retrospectively reviewed the upper gastrointestinal (UGI) findings of eosinophilic esophagitis and correlated them with the clinical, endoscopic and histologic findings in a series of 17 children (12 boys, 5 girls).ResultsUGI findings were normal in 12 children, including 4 who had a normal UGI exam after endoscopic disimpaction for an obstructing food bolus. Five children had strictures identified on UGI: one was demonstrated with endoscopy. This suggests that the impactions and strictures were due to an esophageal dysmotility rather than a fixed anatomic abnormality.ConclusionBecause the UGI findings are frequently normal in eosinophilic esophagitis, radiologists need to have a high index of suspicion for this disease. In children with a strong clinical history, especially impaction in the absence of an esophageal stricture, endoscopy and biopsy are indicated for further evaluation.

Congenital peribronchial myofibroblastic tumor: comparison of fetal and postnatal morphology.

Congenital peribronchial myofibroblastic tumor (CPMT) is a solid pulmonary tumor found in fetuses and neonates with pathology characterized by a proliferation of bland spindled cells with or without irregular cartilaginous islands. It has previously been reported in the literature as a fibrosarcoma, leiomyosarcoma, and hamartoma, among other names. Although complications such as fetal hydrops can occur, the prognosis is generally good if the infant can survive long enough for mass resection. We present a case of a CPMT resected by antenatal fetal surgery at 23 weeks in gestation, with additional tumor resected following birth when the infant was 6 weeks of age. The pathology of this lesion showed a marked increase in the cartilaginous component after birth as well as a decrease in cellularity and mitotic activity. This case presents a unique opportunity to examine the progression of a congenital tumor excised by prenatal and postnatal resections.

Bilateral Burkitt Lymphoma of the Ovaries: A Report of a Case in a Child with Williams Syndrome

A 10-year-old female with Williams Syndrome (WS) presented with a two-month history of fatigue, weight loss, and bilateral ovarian masses. Histologic, immunophenotypic, and cytogenetic studies confirmed the diagnosis of Burkitt lymphoma (BL). While there is no established association between the two disorders, this is the third case in the literature of Burkitt lymphoma in a patient with Williams Syndrome.

Role of Methylenetetrahydrofolate Reductase Gene (MTHFR) 677C>T Polymorphism in Pediatric Cerebrovascular Disorders

Homozygosity for the methylenetetrahydrofolate reductase (MTHFR) 677C>T mutation (MTHFR TT) has been linked to an increased risk for stroke, coronary artery disease, and migraine headaches. The authors analyzed the potential link between MTHFR 677C>T homozygosity and childhood stroke. A true association might facilitate screening, recurrence risk stratification, and treatment in patients with cerebrovascular disease. They performed a retrospective chart review of children tested for the MTHFR 677C>/T mutation; 533 patients underwent MTHFR testing, and 8% were homozygous for the MTHFR 677C>T mutation. There was no difference in the cohort compared with the prevalence in the general population. This suggests that the MTHFR 677 C>T polymorphism played a minimal role or no role in stroke risk. However, the data suggest that the MTHFR TT genotype may influence migraine susceptibility in children because there was a higher proportion of migraine patients (28.6%) with the MTHFR TT homozygous genotype.

RB but not R-HCVAD is a feasible induction regimen prior to auto-HCT in frontline MCL: results of SWOG Study S1106.

Aggressive induction chemotherapy followed by autologous haematopoietic stem cell transplant (auto‐HCT) is effective for younger patients with mantle cell lymphoma (MCL). However, the optimal induction regimen is widely debated. The Southwestern Oncology Group S1106 trial was designed to assess rituximab plus hyperCVAD/MTX/ARAC (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone, alternating with high dose cytarabine and methotrexate) (RH) versus rituximab plus bendamustine (RB) in a randomized phase II trial to select a pre‐transplant induction regimen for future development. Patients had previously untreated stage III, IV, or bulky stage II MCL and received either 4 cycles of RH or 6 cycles of RB, followed by auto‐HCT. Fifty‐three of a planned 160 patients were accrued; an unacceptably high mobilization failure rate (29%) on the RH arm prompted premature study closure. The estimated 2‐year progression‐free survival (PFS) was 81% vs. 82% and overall survival (OS) was 87% vs. 88% for RB and RH, respectively. RH is not an ideal platform for future multi‐centre transplant trials in MCL. RB achieved a 2‐year PFS of 81% and a 78% MRD negative rate. Premature closure of the study limited the sample size and the precision of PFS estimates and MRD rates. However, RB can achieve a deep remission and could be a platform for future trials in MCL.

Isolated juvenile xanthogranuloma in the bone marrow: report of a case and review of the literature.

We report a case of juvenile xanthogranuloma limited to involvement of the bone marrow in a 6-week-old male infant. Evaluation of the bone marrow was a part of the workup for peripheral blood cytopenia. Examination showed hypercellular marrow with paratrabecular clusters of lipidized histiocytes positive for CD68, CD4, and factor XIIIa and negative for S100 and CD1a. Clinical and radiological workup showed no associated skin lesions or osseous or visceral involvement. The patient was started on chemotherapy with clinical improvement and gradual decreased bone marrow involvement. The child is alive and well at 16 months of age. This case represents, to the best of our knowledge, the 1st documented case of juvenile xanthogranuloma with isolated bone marrow involvement sparing skin and viscera.

The College of American Pathologists Guidelines for Whole Slide Imaging Validation Are Feasible for Pediatric Pathology: A Pediatric Pathology Practice Experience

Whole slide imaging (WSI) is rapidly transforming educational and diagnostic pathology services. Recently, the College of American Pathologists Pathology and Laboratory Quality Center (CAP-PLQC) published recommended guidelines for validating diagnostic WSI. We prospectively evaluated the guidelines to determine their utility in validating pediatric surgical pathology and cytopathology specimens. Our validation included varied pediatric specimen types, including complex or less common diagnoses, in accordance with the guidelines. We completed WSI review of 60 surgical pathology cases and attempted WSI review of 21 cytopathology cases. For surgical pathology cases, WSI diagnoses were highly concordant with glass slide diagnoses; a discordant diagnosis was observed in 1 of 60 cases (98.3% concordance). We found that nucleated red blood cells and eosinophilic granular bodies represented specific challenges to WSI review of pediatric specimens. Cytology specimens were more frequently discordant or failed for technical reasons, with overall concordance of 66.7%. Review of pediatric cytopathology specimens will likely require image capture in multiple focal planes. This study is the first to specifically evaluate WSI review for pediatric specimens and demonstrates that specimens representing the spectrum of pediatric surgical pathology practice can be reviewed using WSI. Our application of the proposed CAP-PLQC guidelines to pediatric surgical pathology specimens is, to our knowledge, the first prospective implementation of the CAP-PLQC guidelines.

Xanthogranulomatous Appendicitis in a Child: Report of a Case and Review of the Literature

Xanthogranulomatous inflammation is a well-described inflammatory process, which may involve any organ but is most frequently encountered in the gall bladder and the kidney. There are rare reports of xanthogranulomatous appendicitis (XA) in the adult population, but only one brief mention of such a diagnosis in a child. In this report, we describe the case of an 11-year-old boy who presented with clinical signs and symptoms of acute appendicitis necessitating appendectomy. Upon microscopic examination, the appendix showed the typical features of XA. To the best of our knowledge, this is the first well-described case XA in a noninterval appendix in a child. We also reviewed the limited medical literature on the subject.

Juvenile Myelomonocytic Leukemia: Report of Seven Cases and Review of Literature

Juvenile myelomonocytic leukemia (JMML) is a rare, aggressive, clonal hematopoietic disorder of childhood with features of both myelodysplasia (thrombocytopenia, anemia) and myeloproliferation (leukocytosis, monocytosis). In most cases there is marrow hypercellularity, splenomegaly, and extramedullary involvement. In 1997 an international consensus on terminology was reached and guidelines/criteria for diagnosis were proposed. A recent World Health Organization classification described the current diagnostic criteria of JMML. Although the diagnosis of JMML has been facilitated, it can be challenging, especially in the early stages or when it 1st presents as an extramedullary tumor. We report a series of 7 cases diagnosed over a period of 10 years (from January 1, 1996, to December 31, 2005). Two cases had interesting associated findings that would potentially lead to delay in diagnosis or misdiagnosis. Two other cases had extramedullary involvement with symptoms referable to the organs of involvement at presentation. Clinical and pathologic findings are summarized with a review of relevant literature.