Gonadoblastoma. Immunohistochemical and ultrastructural observations

Gonadoblastoma is an unusual tumor that typically arises in a streak gonad or an abnormal testis of an individual having a Y chromosome. It is a mixed tumor composed of primitive germ cells and sex cord cells arranged in characteristic nests containing hyaline material. Whether the supportive gonadal sex cord cells are granulosa or Sertoli cells has not been clearly established, but one prior ultrastructural study favored Sertoli cell differentiation. Our studies indicate that the intermediate filaments of these cells react to monoclonal antibodies raised against cytokeratin and vimentin. The hyaline material reacts strongly with anti-laminin antibodies, indicating basement membrane material. Additionally, rodlike condensations of the intermediate filaments (historically called Charcot-Böttcher "crystalloids") were similar to those seen in the Sertoli cells of a series of postpubescent testes examined ultrastructurally. These findings support the Sertoli-like differentiation of these cells.