Sertoli cell tumours contain Sertoli cells in a tubular arrangement. They are subclassified in accordance with the WHO as follows: Leydig cell tumours Leydig cell tumours contain Leydig cells, and are usually benign. When located in the hilus they are described as hilus cell tumours. Leydig cell tumours contain Reinke crystals. Lipid cell tumours Lipid cell tumours are characterised by round Leydig-like cells, luteinized stroma, adrenocortical cells and the absence of Reinke crystals.
Gynandroblastoma These are rare ovarian tumours which contain granulosa stromal cells and Sertoli stromal cells. It is characterised by sex cord cells in the form of a ring with nuclei orientated around a central hyalonized body. Treatment Surgery may be the only treatment necessary. Surgical intervention of patients with sex cord-stromal tumours is age dependent.
Trans abdominal hysterectomy or bilateral salpingo-oophorectomy is appropriate for women beyond childbearing age, whereas unilateral oophorectomy is appropriate for younger women. There is a paucity of data on treatment of advanced or recurrent stromal tumours due to their rarity, varied histology and indolence. Combination chemotherapies have yielded some responses in each subtype of sex cord-stromal tumour.
Pelvic radiation has also been used for localised tumours. No effective treatment is available for metastatic lipid cell tumours. In the low percentage of granulosa cell tumours showing aggressive behaviour, any organ can be affected by metastatic disease, although it is usually confined to the pelvis and abdomen. Prognosis The prognosis of sex-cord-stromal tumours is good, as these tumours usually present when confined to a single ovary, and are responsive to chemotherapy.
Patients with juvenile granulosa cell tumours have a good prognosis-mortality is only 1. For individuals with granulosa cell tumours, diffuse growth pattern, increased mitotic figures and cellular atypia correlate with poor prognosis. Adult granulosa cell tumours usually develop in postmenopausal women, recur after longer time intervals, average of 5-years , and the average survival following recurrence is 5-years.
Meanwhile, most juvenile granulosa tumours develop in individuals under years of age, recur within 3-years and then are rapidly fatal. Individuals with completely resected granulosa cell tumours with normal DNA diploid content, have a much better prognosis than when residual tumour remains after laparotomy, and the DNA content is aneuploid. The prognosis of Sertoli-Leydig cell tumours is governed by the stage and differentiation of the tumour. Cytogenetics Cytogenetics Morphological Trisomy 12 is a recurrent finding, often as the sole anomaly in benign sex cord-stromal tumours including fibromas, fibrothecomas, thecomas, granulosa cell tumours.
The consistent occurrence of trisomy 12 in different subtypes of sex cord-stromal tumours suggests a common mechanism of oncogenesis within this diverse group of neoplasms. Numerical abnormalities of chromosome 12 can readily be demonstrated by interphase cytogenetics.
Trisomy 12 and 14, and monosomy 22 are the characteristic recurrent cytogenetic aberrations in granulosa cell tumours. There has been a single case of a Sertoli cell tumour in which cytogenetics was performed. Supernumerary i 1q was present as the sole abnormality. Monosomy 22 was identified as the sole anomaly in a mixed germ cell-sex cord-stromal tumour in the ovary, by both karyotyping and CGH, which may suggest a common pathogenetic mechanism for both tumour types.
Monosomy 22 was also identified as the sole abnormality in a fibrothecoma. Monosomy 22 and trisomy 14 may be early events in the pathogenesis of adult granulosa cell tumour, and particularly adult granulosa-thecoma cell tumours.
Other abnormalities found include: Cytogenetics Molecular CGH and FISH analysis of an ovarian metastasising Sertoli-Leydig cell tumour demonstrated trisomy 8 as the sole anomaly, suggesting that the molecular pathogenesis of Sertoli-Leydig cell tumours differs from the other subtypes of sex cord-stromal tumours. These findings corroborate previous reports of the prevalence of trisomy 12 and 14 and monosomy 22 in granulosa cell tumours.
Note Involvement of the follicle stimulating hormone receptor, FSHR , gene in granulosa cell tumours has now been excluded. An initial study found mutations in 9 out of 13 sex cord tumours, which were later shown to arise from contamination in the tissue processing procedures. Other studies have confirmed the absence of somatic mutations in the FSHR in sex cord-stromal tumours, and in particular granulosa cell tumours.
Data for involvement of the mutations in G-alpha I-2 Gia2 gene, in ovarian granulosa cell tumours is contradictory.
However, 2 studies have excluded any major involvement of this gene in the genesis of ovarian granulosa cell tumours. As discussed earlier, sex cord tumours with annular tubules are present at increased frequency in individuals with PJS, which is caused by germline inactivating mutations of the STK11 gene at 19p Knockout mouse models null for the INHA gene develop granulosa cell tumours suggesting that this gene may act as a tumour suppressor gene.
To find supporting evidence that this was the case in human granulosa cell tumours, It has been investigated whether LOH of the INHA locus at 2qqter was evident in a series of 17 granulosa cell tumours. However LOH was found in only one case, suggesting that this gene does not function as a tumour suppressor gene in granulosa cell tumours in human, contrary to the findings in the mouse model.
However this supports the observation of elevated expression of inhibin which has been reported previously in these tumours. Thus there appears to be an apparent dichotomy between the human granulosa cell tumour and the mouse models.
A study to address whether trisomy 12 was associated with amplification of the KRAS2 oncogene 12p Cyclin D2 CCND2 has been suggested as the candidate gene on 12p, and has been reported to demonstrate increased expression. Altered expression levels of the following genes have also been found in granulosa cell tumours: A role for the INK4 family of cyclin-dependent kinase inhibitors has also been suggested in granulosa cell tumours.
The role of mutations of WT1 in sex cord-stromal tumours was investigated. However loss of the normal wild type allele of WT1 was observed in a granulosa cell tumour present in a patient with Denys-Drash attributable to a germline mutation of WT1. Studies on the role of TP53 mutations in granulosa cell tumours have been contradictory. It was found that over-expression of TP53 was not characteristic of 19 ovarian granulosa cell tumours; whereas other workers found a correlation between expression of mutated TP53 with poor prognosis, which was supported by other findings.
Neither point mutations exons analysed only , nor LOH of TP53 were evident in a series of 17 granulosa cell tumours, suggesting that they have a distinct molecular pathogenesis to that of epithelial ovarian tumours. Mutations outside the hotspot exon were not excluded by their study, but are unlikely to be significant since an association between TP53 and granulosa cell tumour by immunohistochemistry was not demonstrated in th efirst study.