No abstract

Histological features of DC in children are very similar to those described in adults. They should help to distinguish it from ulcerative colitis and Hirschsprung's-associated enterocolitis in order to prevent inappropriate therapy and follow-up. There are many similarities between DC and the normal appendix vermiformis.

Pathological and immunohistochemical findings for specific thyroid epithelial cell markers in thyroid/cervical teratomas from four children are reported. All tumors showed components from the three germinal cell layers. Neoplastic thyroglobulin-immunoreactive thyroid follicles occurred in three intrathyroid teratomas, but the findings were negative in a cervical teratoma in which evidence of its thyroid origin could not be ascertained. As previously suggested on histological grounds, thyroid tissue, other than normal trapped thyroid follicles, is not an infrequent component of cervical teratomas. We found no evidence to support an ultimobranchial origin for these tumors, as previously suggested by Roediger et al. (19), because no calcitonin immunoreaction was observed.