Gonadoblastoma



Gonadoblastoma


Steven S. Shen, MD, PhD

Jae Y. Ro, MD, PhD





Key Facts


Terminology



  • Tumor composed of mixture of seminomatous cells and immature sex cord tumor resembling Sertoli or granulosa cell tumors


Clinical Issues



  • Extremely rare


  • Occurs usually in patients with abnormal, dysgenetic gonads


Microscopic Pathology



  • Nests of tumor cells composed of mixture of 2 types of cells (seminomatous germ cells and sex cord stromal cells)


  • Germ cells are large and round with vacuolated or clear cytoplasm, fine chromatin, and inconspicuous nucleoli


  • Sex cord stromal cells are usually immature Sertoli cells or granulosa cells, but rarely cells resembling Leydig cells or lutein-like cells


  • Small round to oval sex cord derivative forming Call-Exner bodies with central eosinophilic hyaline material


  • Marked hyalinization or calcification present within nests or stroma


  • Adjacent seminiferous tubules with intratubular germ cell neoplasia may be seen


  • Overgrowth of malignant germ cell tumor (usually seminoma) may obliterate gonadoblastomatous foci


Ancillary Tests



  • Germ cells (+) for PLAP, Podoplanin, Oct3/4, CD117


  • Stromal cells (+) for inhibin, calretinin, vimentin, and may be positive for cytokeratin







Gonadoblastoma is characterized by nests containing large seminomatous germ cells image, located in the center and sex cord stromal cells forming Call-Exner-like structures image at the periphery of the nests.






Gonadoblastoma shows smaller sex cord stromal cells forming Call-Exner body-like structures image and large seminomatous cells with abundant clear cytoplasm and prominent nucleoli image.


TERMINOLOGY


Synonyms



  • Mixed germ cell and sex cord stromal cell tumor


Definitions



  • Tumor composed of mixture of seminomatous germ cells and immature sex cord tumor elements resembling Sertoli or granulosa cell tumors


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Extremely rare


    • Occurs usually in patients with abnormal, dysgenetic gonads


  • Age



    • Younger than 20 years old


  • Gender



    • 20% phenotypically male, 80% phenotypically female (during early embryonic development, immature bi-potential gonads fail to differentiate along male pathway)


    • XY gonadal dysgenesis or X0-XY mosaicism may be seen


Presentation



  • Cryptorchidism, hypospadias or other ambiguous genitalia, and gynecomastia


Treatment



  • Surgical approaches



    • Bilateral gonadectomy is recommended and curative


Prognosis



  • Excellent if no associated invasive germ cell or malignant sex cord stromal tumor components


MACROSCOPIC FEATURES


General Features



  • Gray to yellow-brown mass with a soft, fleshy or firm and gritty cut surface


  • Streak gonads with incidental findings in very smallsized tumors


  • Invasive malignant germ cell tumor component, usually seminoma, results in larger tumors


Size



  • Range: Microscopic focus to 8 cm


MICROSCOPIC PATHOLOGY


Histologic Features



  • Nests of tumor cells composed of mixture of 2 types of cells (seminomatous germ cells and sex cord stromal cells)


  • Germ cells are large and round with vacuolated or clear cytoplasm, central nuclei with fine chromatin and prominent nucleoli


  • Sex cord stromal cells are usually immature Sertoli cells or granulosa cells, but rarely cells resemble Leydig cells or luteinizing theca-like cells


  • Sex cord stromal cells are located at periphery of nests


  • Small round to oval sex cord derivative cells form Call-Exner bodies with central eosinophilic hyaline material


  • Marked hyalinization or calcification present within nests or stroma


  • Adjacent seminiferous tubules with intratubular germ cell neoplasia may be seen


  • Overgrowth of malignant germ cell tumor (usually seminoma) may obliterate gonadoblastomatous foci


Predominant Pattern/Injury Type



  • Neoplastic; nests of tumor cells with germ cells and sex cord stromal tumor



Predominant Cell/Compartment Type



  • Mixed germ cells and sex cord stromal cells


ANCILLARY TESTS


Immunohistochemistry



  • Germ cells positive for PLAP, Podoplanin(D2-40), Oct3/4, SALL4, CD117


  • Gonadal stromal cells positive for inhibin, calretinin, Melan-A(MART-1), vimentin; may be positive for cytokeratin


DIFFERENTIAL DIAGNOSIS


Unclassified Mixed Germ Cell and Sex Cord Stromal Tumors

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Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Gonadoblastoma

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