Gonadoblastoma

Gonadoblastoma
Steven S. Shen, MD, PhD
Jae Y. Ro, MD, PhD
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
Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Gonadoblastoma

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