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

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

, located in the center and sex cord stromal cells forming Call-Exner-like structures

at the periphery of the nests.

Gonadoblastoma shows smaller sex cord stromal cells forming Call-Exner body-like structures

and large seminomatous cells with abundant clear cytoplasm and prominent nucleoli

TERMINOLOGY

Synonyms

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

Treatment

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

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

Predominant Cell/Compartment Type

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