Testicular Tumours: Granulosa Cell Tumour :Juvenile-type Granulosa Cell Tumour

II Juvenile Granulosa Cell Tumour:

Juvenile granulosa cell tumours occur in the first few months of life. These tumours are most common neonatal testicular tumour (6% of childhood testicular tumours) and may pose major problems in differential diagnosis. These neoplasms may occur in infants with mixed gonadal dysgenesis, (tumours may be associated with trisomy 12 and sex chromosome mosaicism)
Gross features: On gross examination, these tumours vary greatly in size, with many of them replacing most or all of the testis. They are usually well circumscribed and are composed of white to yellow, often lobulated tissue. Cysts may be present.
Microscopic features: Microscopic examination reveals a spectrum of patterns , ranging from predominantly epithelial to predominantly stromal. A mixed pattern, usually with at least focally prominent follicles, is most common. The follicles are often variable in both size and shape. In some cases, lipid vacuoles are conspicuous within the tumour cells. One may see solid or hollow tubules, or cords composed of or lined by cells resembling Sertoli cells. Occasionally, a more diffuse pattern is seen. In these cases the cells are small with hyperchromatic nuclei and mitotic activity may be prominent. Usually, the nuclei of the granulosa cells lack the features of those of ovarian adult granulosa cell tumours, such as nuclear grooves.
Special stains: Positive stains: vimentin, low molecular weight cytokeratin, actin, desmin, CD99.
Differential diagnosis: Juvenile granulosa cell tumour was occasionally misdiagnosed as yolk sac tumour. The follicular pattern of juvenile granulosa cell tumour is the major clue to the diagnosis. It is also crucial to be aware of the existence of juvenile granulosa cell tumour as an entity in the testis and its great tendency to occur in the first few months of life, whereas the yolk sac tumour occurs generally from 1 year on.
The mitotic activity of this tumour and spindle cells may lead to the misdiagnosis of rhabdomyosarcoma. The gross appearance is important - sarcomas are almost always paratesticular rather than testicular. It may not always be possible to make this distinction when the sarcoma reaches a large size.

Abstract:
Juvenile granulosa cell tumor of the infantile testis. A report of 14 cases.Am J Surg Pathol.1985;9(2):87-94.
Fourteen testicular tumors diagnosed in infants less than 6 months of age had a distinctive appearance resembling that of the juvenile granulosa cell tumor of the ovary. One of them was discovered at autopsy in an infant of 30 weeks' gestational age; seven were diagnosed during the first few days of life, and the remainder between 3 weeks and 4 1/2 months of age. Enlargement of a scrotal testis was the presenting manifestation in 10 cases and abdominal swelling in one case; one tumor was found in a descended testis that had undergone torsion and one was discovered in an inguinal testis at the time of inguinal herniorrhaphy. The tumors ranged from 0.8 to 5.0 cm in diameter and were cystic or partly cystic and partly solid. Microscopic examination disclosed both follicular and solid components. The follicles were of varying sizes and contained eosinophilic or basophilic fluid that stained positively for mucin in some of the cases. The solid foci typically had a nodular arrangement and occasionally were hyalinized or had a basophilic background due to the presence of intercellular mucin. The neoplastic cells contained moderate to large amounts of eosinophilic cytoplasm and round to oval hyperchromatic nuclei, which typically lacked grooves. The mitotic rate varied from less than 1-24/10 high-power fields. Limited follow-up examination revealed no evidence of recurrence. The microscopic features of these neoplasms warrant their designation as "juvenile granulosa cell tumor.

Abstract:
Juvenile granulosa cell tumor of the infantile testis. Evidence of a dual epithelial-smooth muscle differentiation. Am J Surg Pathol. 1996 Jan;20(1):72-9.
We report the ultrastructure and immunohistochemical profile of seven juvenile granulosa cell tumors of the infantile testis. The infants' ages ranged from 1 day to 11 months. All tumors had characteristics ultrastructure with a mixture of spindle smooth-muscle and theca cells and polygonal granulosa cells. Clusters of polygonal granulosa cells were invested by a continuous basal lamina and contained bundles of distinct cytoplasmic filaments with evenly distributed dense bodies resembling smooth muscle. These filaments were occasionally attached to well-developed, prominent desmosomes. Tumor cells had a conspicuous rough endoplasmic reticulum and Golgi complex and occasional neutral fat droplets. In all tumors, mitochondria had laminated cristae and only rarely were there cristae with a tubulovesicular pattern characteristic of steroid secreting cells. Tumor cells stained focally with low-molecular-weight cytokeratins (8,18, and 19), smooth-muscle-specific actin, desmin, and more noticeably with vimentin. These ultrastructural and immunohistochemical features of dual epithelial-mesenchymal differentiation and distinct muscle-like filaments with dense bodies are characteristic of the juvenile granulosa cell tumor of the infantile testis.

Abstract:
Testicular juvenile granulosa cell tumor in an infant with X/XY mosaicism clinically diagnosed as true hermaphroditism. Am J Surg Pathol. 1994 Mar;18(3):316-22.
We report a testicular juvenile granulosa cell tumor (T-JGCT) with characteristic clinical and histopathological features. The tumor was present in the left abdominal testis of a 7-month-old infant with a 45,X/46,XY karyotype and ambiguous genitalia. Preoperatively, the infant was diagnosed as having functional testicular and ovarian elements based on elevated levels of serum testosterone and estradiol following human chorionic gonadotropin and human menopausal gonadotropin administration, respectively. Histologically, the left gonad contained a tumorous lesion composed of an admixture of cellular areas and multiple cystic follicles that had some continuity with the adjacent testicular tubules. Some tumor cells showed immunoreactivity for estradiol. The right gonad was a streak gonad containing small irregular nests of sex cord-type cells. No maturing ovarian follicle was present in either gonad. To our knowledge, this is the fifth reported case of T-JGCT with abnormal sex chromosomes, and the first case of T-JGCT confirmed to have not only the morphological but also the functional characteristics of granulosa cells.

Abstract:
Congenital testicular juvenile granulosa cell tumor in a neonate with X/XY mosaicism. Am J Surg Pathol. 1986 Aug;10(8):577-83.
A congenital sex cord-stromal tumor of the testis with morphologic features of juvenile granulosa cell tumor is reported. The tumor occurred in an abdominal testis of a newborn infant with an X/XY karyotype and ambiguous genitalia and presented as a partially cystic mass associated with ascites. Histologically the tumor was comprised of an admixture of solid, cellular, poorly differentiated lobules mimicking graafian follicles. Residual hypoplastic testicular tissue was present at the periphery. This is the 19th reported case of testicular juvenile granulosa cell tumor and the fourth with an underlying sex chromosome anomaly, further emphasizing the relationship of this uncommon neoplasm to abnormal sexual or gonadal development.