RÉSUMÉ
<p><b>BACKGROUND</b>Non-Hodgkin lymphoma is the fourth most common malignant tumors in children, Burkitt lymphoma (BL) accounts for 30-50% of all pediatric lymphomas. The aim of this study was to investigate the clinicopathologic features, immunophenotype, Epstein-Barr virus (EBV) infection and c-myc gene rearrangement of sporadic BL in children.</p><p><b>METHODS</b>Ninety-two cases of pediatric BL were retrospectively analyzed for clinical features, immunohistochemistry, EBV-encoded RNA (EBER) status by in situ hybridization and c-myc gene rearrangement by fluorescence in situ hybridization.</p><p><b>RESULTS</b>In the 92 cases, male is predominant in sex distribution (M: F = 3.38:1). The average age at diagnosis was 4.97 years. Polypoid BL showed a lower clinical stage (P = 0.002), and advanced clinical stage and low serum albumin level at diagnosis were associated with poor outcome (P = 0.024 and 0.053, respectively). The positive expression of CDl0, B-cell lymphoma-6, MUMl and EBER were 95.7% (88 cases), 92.4% (85 cases), 22.8% (21 cases), 41.3% (38 cases), respectively. The expression of MUM1 were not associated with EBV infection status (P = 1.000). c-myc gene rearrangement was detected in 94.6% (87/92). Clinical treatment information for 54 cases was collected, 21 patients died of tumor after surgery alone, 33 patients received surgery and chemotherapy, and of which six patients died shortly afterwords (MUM1 positive expression in 3 cases, P = 0.076).</p><p><b>CONCLUSIONS</b>The anatomical location, growth pattern and serum albumin level of BL were associated with biological behavior. MUM1 may be a potential adverse prognostic marker, and not associated with EBV infection status.</p>
Sujet(s)
Adolescent , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Nourrisson , Mâle , Lymphome de Burkitt , Diagnostic , Épidémiologie , Métabolisme , Infections à virus Epstein-Barr , Diagnostic , Métabolisme , Immunohistochimie , Hybridation fluorescente in situ , Facteurs de régulation d'interféron , Métabolisme , Répartition par sexeRÉSUMÉ
<p><b>OBJECTIVE</b>To study the clinicopathologic features and biologic behavior of pediatric immature teratoma.</p><p><b>METHODS</b>The clinical data, pathologic features, immunohistochemical findings (for cyclin D1, P27 and Ki-67) and follow-up information of 39 cases of pediatric immature teratoma were analyzed.</p><p><b>RESULTS</b>Amongst the 39 cases studied, 12 arose in the sacrococcygeal region, 12 in testis, 5 in retroperitoneum, 4 in ovary, 4 in abdomen and 2 in mediastinum. Histologically, 16 cases were of grade 1, 8 cases of grade 2 and 15 cases of grade 3. Seven of the cases contained foci of yolk sac tumor. Immature neuroepithelial features used in histologic grading included the presence of primitive neural tubules, immature rosettes, undifferentiated neuroblastoma cells and primitive neuroectodermal structures. Immunohistochemical study showed that cyclin D1 was positive in 3 cases of grade 1 tumors, 4 cases of grade 2 tumors and 9 cases of grade 3 tumors. The positivity rates for p27 were 8, 3 and 6 cases respectively, while those for Ki-67 were 3, 4 and 13 cases respectively. Follow-up data were available in 30 cases. Three of them, including 2 cases with histologic grade 3 (with or without yolk sac tumor component), recurred after operation.</p><p><b>CONCLUSIONS</b>The expression of cyclin D1 and Ki-67 is a useful adjunct in histologic grading. On the other hand, p27 overexpression shows little correlation with tumor grade. The prognosis of immature teratoma in children is different from that in adults. Sacrococcygeal immature teratoma occurring in patients younger than 1 year old and with low histologic grade do not require postoperative chemotherapy if the tumor is completely excised. Similarly, for testicular immature teratoma occurring in patients below 1 year of age, regardless of tumor grading, need no adjunctive therapy. On the other hand, ovarian immature teratoma with high histologic grade requires postoperative chemotherapy, regardless of age of the patients. The presence of microscopic foci of yolk sac tumor is a useful predictor of recurrence in pediatric immature teratoma.</p>