Müllerian adenosarcoma with a neuroectodermal component associated with an endometriotic cyst of the ovary: a case report

Reported here is a case of Müllerian adenosarcoma of the ovary which contained a primitive neuroectodermal tissue component within the stroma. The adenosarcoma coexisted with clear cell adenocarcinoma in an endometriotic cyst. The patient was a 33-year-old woman with a large unilocular endometriotic cyst of the right ovary. On the internal wall of the cyst, both a plaque-like protrusion with a papillary surface and a dome-like mural nodule were noted. The former exhibited features of Müllerian adenosarcoma, and the latter showed those of clear cell adenocarcinoma. In the deeper portion of adenosarcoma, teratoma-like tissue which contained various tissue components including primitive neuroectodermal tissue was found. The presence of primitive neuroectodermal tissue in the stroma of adenosarcoma suggested the diagnosis of 'adenosarcoma with neuroectodermal differentiation' ('teratoid adenosarcoma'), although the possibility of the incidental occurrence of an immature teratoma could not be completely excluded.