(1) Other asymmetric anatomical features - such as placement of the heart and liver - are products of different layers, the mesoderm and endoderm .(2) These cells, usually seen as being mesodermal, apparently represent another cell line originating from endoderm .(3) In addition, they act as messengers, bearing molecular orders to the mesoderm and endoderm which they contact on arrival.(4) In this tissue, therefore, the fate of some of the cells has been changed from prospective gut endoderm to mesoderm and ectoderm.(5) At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm , which extend throughout the animal.(6) We still consider this a benign tumor because no endodermal sinus components were evident.(7) Neither ectodermal nor endodermal components were identified in the sections examined.(8) They derive from misplaced embryonic and endodermic cells(9) The most interesting and most perplexing question is how ectodermal glands can be derived from what has been thought to be endodermal and mesodermal derivatives.(10) The tumor demonstrated predominantly mature ectodermal, mesodermal, and endodermal elements.(11) Spinal endodermic cysts are rare and may be associated with other congenital anomalies.(12) Examination of the surgical specimen revealed findings characteristic of endodermal sinus tumor.
