OCT4 immunohistochemistry may be necessary to identify the real risk of gonadal tumors in patients with Turner syndrome and Y chromosome sequences

Clinical characteristics and surgical treatment of children with 45, X/46, XY differences of sex development

OBJECTIVE

This study retrospectively analyzes the clinical data of 18 children with 45,X/46,XY differences of sex development (DSD), summarizes their clinical features and explores gonadal and Müllerian duct remnants surgical treatment methods.

METHODS

The clinical data of 18 children with karyotype 45,X/46,XY diagnosed in the Department of Urology of Hunan Children's Hospital from March 2011 to October 2021 were collected. All children underwent HCG stimulation testing, laparoscopic exploration, urethroscopy and bilateral gonadal biopsy. After DSD multidisciplinary team (MDT) meeting, some children underwent gonadectomy and genitalia reconstructive surgeries.

RESULTS

The median age at first diagnosis was 1 year and 4 months (range: 10 months ∼ 16 years and 3 months). 5 children presented with female gender; they all maintained their gender assignment. The external masculinisation score (EMS) of patients raised as female was 1 (0∼3) [median (range)]. 13 children presented with male gender, 10 maintained a male gender, 3 were assigned a neutral gender. The EMS of the children raised as male was 5 (2-8) [median (range)], the EMS of the children raised as neutral gender was 4 (3.5-9.5) [median (range)]. The HCG stimulation test was positive in 11 cases, partially positive in 2 case, and negative in 5 cases. There was no relationship between the percentage of chimerism (45X ratio) and the appearance and severity of genital abnormalities. (t=-1.08, P=0.298). There was 1 case of complete gonadal dysgenesis (CGD), 10 cases of mixed gonadal dysgenesis (MGD), 5 cases of partial gonadal dysgenesis (PGD), 1 case of bilateral normal testes and 1 case of ovotesticular DSD (split-lateral type). No gonadal specimen showed germ cell tumor changes. Five cases selected to maintain the female gender, among which 3 cases underwent bilateral gonadectomy and genitalia reconstructive surgeries. Among the 10 children who chose to maintain the male gender, unilateral streak gonadectomy was performed in 4 (57.1%) with MGD, unilateral dysgenetic orchiectomy in 1 (25%) with PGD, and right ovariectomy in 1 with OTDSD. Nine of them underwent genitalia reconstructive surgeries. Four of them preserved their uterus and vagina did not have any complications during the follow-up period.

CONCLUSION

Hypospadias combined with cryptorchidism and residual Müllerian duct structures is the most common phenotype of children with 45, X/46, XY DSD. Mixed gonadal dysgenesis (MGD) is the most common gonadal type. Gender assignment should be carefully selected after a thorough evaluation, while genitalia reconstructive surgery can be considered in selected patients. In children who choose the male gender, the Müllerian duct can be preserved.

Development of the human fetal testis: Morphology and expression of cellular differentiation markers

A comprehensive immunohistochemical ontogeny of the developing human fetal testis has remained incomplete in the literature to date. We collected human fetal testes from 8 to 21 weeks of fetal age, as well as postnatal human testes at minipuberty, pre-pubertal, and pubertal stages. Immunohistochemistry was performed with a comprehensive panel of antigens targeting gonadocytes, Sertoli cells, fetal Leydig cells, peritubular myoid cells, and other hormonal and developmental targets. Testicular cords, precursor structures to seminiferous tubules, developed from 8 to 14 weeks of fetal age, separating the testis into the interstitial and intracordal compartments. Fetal gonadocytes were localized within the testicular cords and evaluated for Testis-Specific Protein Y, Octamer-binding transcription factor 4, Sal-like protein 4, and placental alkaline phosphatase expression. Fetal Sertoli cells were also localized in the testicular cords and evaluated for SRY-box Transcription Factor 9, inhibin, and anti-Mullerian hormone expression. Fetal Leydig cells were present in the interstitium and stained for cytochrome p450c17 and calretinin, while interstitial peritubular myoid cells were examined using smooth muscle α-actin staining. Androgen receptor expression was localized close to the testicular medulla at 8 weeks and then around the testicular cords in the interstitium as they matured in structure. Postnatal staining showed that Testis-Specific Protein Y remained positive of male gonadocytes throughout adulthood. Anti-Mullerian hormone, SRY-box Transcription Factor 9, and Steroidogenic factor 1 are expressed by the postnatal Sertoli cells at all ages examined. Leydig cell markers cytochrome p450c17 and calretinin are expressed during mini-puberty and puberty, but not expressed during the pre-pubertal period. Smooth muscle α-actin and androgen receptor were not expressed during mini-puberty or pre-puberty, but again expressed during the pubertal period. The ontogenic map of the human fetal and postnatal testicular structure and expression patterns described here will serve as a reference for future investigations into normal and abnormal testicular development.

Prevalence and characteristics of gonadoblastoma in a retrospective multi-center study with follow-up investigations of 70 patients with Turner syndrome and a 45,X/46,XY karyotype

INTRODUCTION

A gonadectomy is currently recommended in patients with Turner syndrome (TS) and a 45,X/46,XY karyotype, due to a potential risk of gonadoblastoma (GB). However, the quality of evidence behind this recommendation is low.

OBJECTIVE

This study aimed to evaluate the prevalence of GB, its characteristics, as well as its risk factors, according to the type of Y chromosomal material in the karyotype.

METHODS

Our study within French rare disease centers included patients with TS and a 45,X/46,XY karyotype, without ambiguity of external genitalia. Clinical characteristics of the patients, their age at gonadectomy, and gonadal histology were recorded. The regions of the Y chromosome, the presence of TSPY regions, and the percentage of 45,X/46,XY mosaicism were evaluated.

RESULTS

A total of 70 patients were recruited, with a median age of 29.5 years (21.0-36.0) at the end of follow-up. Fifty-eight patients had a gonadectomy, at a mean age of 15 ± 8 years. GB was present in nine cases. Two were malignant, which were discovered at the age of 14 and 32 years, without metastases. Neither the percentage of XY cells within the 45,X/46,XY mosaicism nor the number of TSPY copies was statistically different in patients with or without GB (P = 0.37). However, the entire Y chromosome was frequent in patients with GB (6/9).

CONCLUSIONS

In our study, including a large number of patients with 45,X/46,XY TS, the prevalence of gonadoblastoma is 12.8%. An entire Y chromosome appears as the main risk factor of GB and should favor early gonadectomy.

SIGNIFICANT STATEMENT

About 10% of patients with TS have a karyotype containing Y chromosomal material: 45,X/46,XY. Its presence is related to the risk of GB. Therefore, a prophylactic gonadectomy is currently recommended in such patients. However, the quality of evidence is low. Our objective was to evaluate the prevalence of GB according to the type of Y-chromosomal material. We found a prevalence of GB of 12.8% in a cohort of 70 TS patients. No sign of hyperandrogenism was observed. The entire Y chromosome was the most frequent type of Y-material in patients with GB. As the prognosis of these tumors was good, a delay of surgery might be discussed.

Consensus guide on prophylactic gonadectomy in different sex development

The risk of suffering from gonadal germ cell tumors (GCT) is increased in some patients with different sexual development (DSD), mainly in those with Y chromosome material. This risk, however, varies considerably depending on a multitude of factors that make the decision for prophylactic gonadectomy extremely difficult. In order to make informed recommendations on the convenience of this procedure in cases where there is potential for malignancy, this consensus guide evaluates the latest clinical evidence, which is generally low, and updates the existing knowledge in this field.

Hyperandrogenism in a girl with Turner syndrome: A case report

RATIONALE

The gonads of patients with Turner syndrome (TS) were previously thought to be funicular. There was no increase in androgen level. The gonad that is testis should be taken into account when the patient's serum testosterone level was abnormal and hypothalamic-pituitary-adrenal disease was excepted.

PATIENT CONCERNS

A 16-year-old girl was admitted to our hospital because of chromosomal abnormalities and elevated androgen levels.

DIAGNOSIS

Turner syndrome could be diagnosed since her chromosome karyotype was 45, XO.

INTERVENTIONS

The patient was given bilateral gonadectomy and hormone replacement therapies.

OUTCOME

The level of the patient's serum testosterone was <0.45 nmol/L 2 days after the operation. Postoperative pathology showed that her right gonad was testicular tissue. The patient's menstruation was normal after the treatment of hormone replacement therapy.

LESSONS

All TS patients should get Y chromosome material screening. Gonadectomy could be done for Turner syndrome patients who have hyperandrogenism or Y chromosome material.

Detection of the SRY gene in patients with Turner Syndrome

BACKGROUND

If turner syndrome (TS) patients have a Y-containing cell line, they have an increased risk for gonadal tumors. TS patients are therefore screened for Y-chromosome and Y-specific sequences, such as SRY, DYZ1, DYZ3, DYS132, ZFY, TSPY, etc. In addition, since the dysgenetic gonad may include the stroma and granulosa/sertoli cells, which produce androgens, virilization can seen in girls with Y-chromosomal material. Prophylactic gonadectomy may therefore be required for optimal management in such patients. Our aim is to discuss our observations in the follow-up of TS patients.

METHODS

SRY was investigated in 71 out of 85 TS cases (aged 3 months-27 years) between 2005 and 2017. Fluorescent in situ hybridization (FISH) was used until 2014, after which SRY analysis was performed using the polymerase chain reaction (PCR) method. SRY analysis was performed a second time using PCR in 25 cases previously investigated with FISH.

RESULTS

We identified no positive cases. No pathological findings in terms of virilization, clitoromegaly, or posterior labial adhesions were also determined in our TS cases. Further studies were not required since no pathological findings also were detected at ultrasonography.

CONCLUSION

If Y-chromosome material has not been detected by conventional cytogenetic methods in TS patients with masculine features, further techniques should be applied to prevent the risk of invasive tumors, such as multiple sequences beside the Y centromere. This approach will prevent overtreatment.

Clinical and cytogenetic features of 516 patients with suspected Turner syndrome - a single-center experience

BACKGROUND

Clinical suspicion of Turner syndrome (TS) may be challenging. Short stature and absent puberty are not mandatory and the dysmorphic picture is widely variable. The aim of the study was to describe a representative sample of patients with suspected TS in a single center and to verify which set of features may help discriminate those with TS.

METHODS

This was a retrospective study of patients with suspected TS evaluated between 1989 and 2012 with the same clinical and cytogenetic protocols. Data regarding reason for referral, age and height at diagnosis, birth data, pubertal features and dysmorphisms were analyzed.

RESULTS

TS was diagnosed in 36% of 516 patients; structural chromosome anomalies predominated (42%). Short stature was the main reason for referral of patients with and without TS. The mean age of patients at first visit, with TS or without TS was similar (11.89 and 11.35 years, respectively), however, infants and adolescents predominated in the TS group. The mean full-term birth weight was lower in patients with TS as well as height at diagnosis, but normal height z-score was found in 17% of patients. Spontaneous puberty occurred in 30% of TS patients aged 13 years or more, but most had pubertal delay. Residual lymphedema, webbed neck, cubitus valgus, hyperconvex nails, shield chest, abnormal nipples, pigmented nevi, short fourth metacarpal and shorter height were the best discriminators for girls with TS.

CONCLUSIONS

Though short stature, pubertal delay and typical stigmata should prompt investigation of TS, lack of one of these features should not exclude this hypothesis. Dysmorphisms other than those considered "typical" should be sought on physical examination.

A practical guide for evaluating gonadal germ cell tumor predisposition in differences of sex development

Differences of Sex Development (DSD) includes a wide spectrum of etiologies and phenotypes. A subset of individuals with DSDs are predisposed to gonadal germ cell tumor (GCT). In this setting, GCT risk varies widely, depending on the DSD molecular etiology and penetrance. Prognostication based on molecular diagnosis remains challenging, as natural history data specific to recently identified molecular causes of DSD is lacking. In this review, we provide a framework for the clinical geneticist to consider GCT tumor risk in the patient with DSD. We discuss germ cell development and etiology of GCT growth, along with parameters to consider when recommending prophylactic gonadectomy including fertility, hormonal output, and malignant GTC treatment outcomes. Shortly after the 2006 reorganization of DSD nomenclature, literature reviews of natural history publications stratified GCT risk by a chromosomal, pathological, and hormonal taxonomy. Our 2017 literature review reveals a larger body of publications. However, the broad DSD GCT risk stratification within the 2006 taxonomy remains stable. We discuss precise GCT risk assessment for specific diagnoses, including androgen insensitivity, Smith-Lemli-Opitz, and 46,XY with MAP3K1 mutations and gonadal dysgenesis, as examples. We also examine the GCT risk in non-DSD syndromes, in addition to the cancer risks in DSD patients with dimorphic gonads and genitalia. This review is intended to provide a nuanced assessment of relative germ cell tumor risk in the DSD patient, including modern precise molecular diagnosis, for use by the clinical geneticist.

Gonadoblastoma in patients with 45,X/46,XY mosaicism: A 16-year experience

BACKGROUND

It is recognised that individuals with a 45,X/46,XY karyotype, known as Turner mosaic syndrome with Y chromosome material (TMSY), have an increased risk of developing gonadoblastoma (GB), which may then devolve into one of a number of germ cell malignancies. Hence, children with TMSY are usually recommended to undergo prophylactic gonadectomy.

OBJECTIVE

We designed this study to describe the phenotypic features of our series of children with TMSY who underwent prophylactic gonadectomy in order to evaluate the prevalence of GB and germ cell malignancies in their resected specimens.

STUDY DESIGN

This is a retrospective case series wherein we comprehensively reviewed the clinical, histological, and cytogenetic features of all patients who underwent prophylactic gonadectomy at three tertiary paediatric referral centres over 16 years. Cases were identified from surgical logbooks and through the institutional histopathology database. Data were collected with particular reference to clinical phenotype, predominant karyotype cell line, operative management, anatomical findings and the presence of neoplastic changes.

RESULTS

Fourteen children ranging in age at the time of surgery from 2 weeks to 17 years were included in the series. Eleven children were reared as females. The three children who were reared as males had severe penoscrotal hypospadias. The 46,XY cell line was the predominant cell line in seven (50%) cases in blood lymphocytes. The resected specimens from four patients (28.6%) contained GB, with three patients having bilateral GB. This sub-group of patients with GB were aged 5 months, 48 months, 71 months, and 13 years. GB arose in one patient with and three patients without genital virilisation. There was no focus of invasive germ cell tumour in any specimen.

DISCUSSION

GB may be present in infants with TMSY as young as 5 months, even with low levels of Y chromosome material. The prevalence of GB in prophylactic gonadectomy specimens is similar to many previously reported series, although the absence of dysgerminoma in our series is reassuring. The exclusive presence of GB in intra-abdominal gonads is in keeping with the findings of several other series.

CONCLUSION

Owing to the presence of gonadoblastoma in the gonads of children with TMSY as young as 5 months, we recommend that all patients with intra-abdominal gonads in the context of TMSY should duly undergo prophylactic gonadectomy, although the timing of such surgery can be discussed with parents during counselling regarding the risk of malignancy.

Identification of Y-Chromosome Sequences in Turner Syndrome

OBJECTIVES

To investigate the presence of Y-chromosome sequences and determine their frequency in patients with Turner syndrome.

METHODS

The study included 23 patients with Turner syndrome from Brazil, who gave written informed consent for participating in the study. Cytogenetic analyses were performed in peripheral blood lymphocytes, with 100 metaphases per patient. Genomic DNA was also extracted from peripheral blood lymphocytes, and gene sequences DYZ1, DYZ3, ZFY and SRY were amplified by Polymerase Chain Reaction.

RESULTS

The cytogenetic analysis showed a 45,X karyotype in 9 patients (39.2 %) and a mosaic pattern in 14 (60.8 %). In 8.7 % (2 out of 23) of the patients, Y-chromosome sequences were found. This prevalence is very similar to those reported previously. The initial karyotype analysis of these patients did not reveal Y-chromosome material, but they were found positive for Y-specific sequences in the lymphocyte DNA analysis.

CONCLUSION

The PCR technique showed that 2 (8.7 %) of the patients with Turner syndrome had Y-chromosome sequences, both presenting marker chromosomes on cytogenetic analysis.

[Prevalence of Y-chromosome sequences and gonadoblastoma in Turner syndrome]

OBJECTIVE

To assess the prevalence of Y-chromosome sequences and gonadoblastoma in patients with Turner syndrome using molecular techniques.

DATA SOURCE

A literature search was performed in Pubmed, limiting the period of time to the years 2005 to 2014 and using the descriptors: Turner syndrome and Y sequences (n=26), and Turner syndrome and Y-chromosome material (n=27). The inclusion criteria were: articles directly related to the subject and published in English or Portuguese. Articles which did not meet these criteria and review articles were excluded. After applying these criteria, 14 papers were left.

DATA SYNTHESIS

the main results regarding the prevalence of Y-chromosome sequences in Turner syndrome were: 1-about 60% of the studies were conducted by Brazilian researchers; 2-the prevalence varied from 4.6 to 60%; 3-the most frequently investigated genes were SRY, DYZ3 and TSPY; 4-seven studies used only PCR, while in the remaining seven it was associated with FISH. Nine of the 14 studies reported gonadectomy and gonadoblastoma. The highest prevalence of gonadoblastoma (33%) was found in two studies. In five out of the nine papers evaluated the prevalence of gonadoblastoma was 10 to 25%; in two of them it was zero.

CONCLUSIONS

according to these data, molecular analysis to detect Y-chromosome sequences in TS patients is indicated, regardless of their karyotype. In patients who test positive for these sequences, gonadoblastoma needs to be investigated.

Pathogenesis of germ cell neoplasia in testicular dysgenesis and disorders of sex development

Development of human gonads is a sex-dimorphic process which evolved to produce sex-specific types of germ cells. The process of gonadal sex differentiation is directed by the action of the somatic cells and ultimately results in germ cells differentiating to become functional gametes through spermatogenesis or oogenesis. This tightly controlled process depends on the proper sequential expression of many genes and signalling pathways. Disturbances of this process can be manifested as a large spectrum of disorders, ranging from severe disorders of sex development (DSD) to - in the genetic male - mild reproductive problems within the testicular dysgenesis syndrome (TDS), with large overlap between the syndromes. These disorders carry an increased but variable risk of germ cell neoplasia. In this review, we discuss the pathogenesis of germ cell neoplasia associated with gonadal dysgenesis, especially in individuals with 46,XY DSD. We summarise knowledge concerning development and sex differentiation of human gonads, with focus on sex-dimorphic steps of germ cell maturation, including meiosis. We also briefly outline the histopathology of germ cell neoplasia in situ (GCNIS) and gonadoblastoma (GDB), which are essentially the same precursor lesion but with different morphological structure dependent upon the masculinisation of the somatic niche. To assess the risk of germ cell neoplasia in different types of DSD, we have performed a PubMed search and provide here a synthesis of the evidence from studies published since 2006. We present a model for pathogenesis of GCNIS/GDB in TDS/DSD, with the risk of malignancy determined by the presence of the testis-inducing Y chromosome and the degree of masculinisation. The associations between phenotype and the risk of neoplasia are likely further modulated in each individual by the constellation of the gene polymorphisms and environmental factors.

45,X mosaicism with Y chromosome presenting female phenotype

Prophylactic gonadectomy is recommended in patients with 45,X mosaicism with the Y chromosome and presenting a female phenotype because of the risk of gonadoblastoma development. The characteristics of this disorder remain unclear because of its low incidence. We report 4 patients with 45,X mosaicism with the Y chromosome and presenting complete female external genitalia. We analyzed the characteristics and the macroscopic and histopathological findings of their gonads and performed hormonal assays of the 4 patients. All 4 patients were referred to us with short stature as the chief complaint. Chromosomal studies revealed 45,X/47,XYY in 1, and the others had a 45,X/46,XY karyotype. Three patients (6 gonads) underwent laparoscopic bilateral gonadectomy. The macroscopic appearance of gonads of 1 patient was similar to an ovary, whereas gonads of the rest appeared as streak gonads. The histopathological findings revealed bilateral gonadoblastoma in 1 patient, although the macroscopic findings did not show tumor characteristics. It is impossible to distinguish the histopathological findings of gonads according to their macroscopic appearance among patients with 45,X mosaicism with the Y chromosome and presenting a female phenotype.

Y chromosome in Turner syndrome: detection of hidden mosaicism and the report of a rare X;Y translocation case

Turner syndrome (TS) is a common genetic disorder in females associated with the absence of complete or parts of a second sex chromosome. In 5-12% of patients, mosaicism for a cell line with a normal or structurally abnormal Y chromosome is identified. The presence of Y-chromosome material is of medical importance because it results in an increased risk of developing gonadal tumours and virilisation. Molecular study and fluorescence in situ hybridisation approaches were used to study 74 Brazilian TS patients in order to determine the frequency of hidden Y-chromosome mosaicism, and to infer the potential risk of developing malignancies. Additionally, we describe one TS girl with a very uncommon karyotype 46,X,der(X)t(X;Y)(p22.3?2;q11.23) comprising a partial monosomy of Xp22.3?2 together with a partial monosomy of Yq11.23. The presence of cryptic Y-chromosome-specific sequences was detected in 2.7% of the cases. All patients with Y-chromosome-positive sequences showed normal female genitalia with no signs of virilisation. Indeed, the clinical data from Y-chromosome-positive patients was very similar to those with Y-negative results. Therefore, we recommend that the search for hidden Y-chromosome mosaicism should be carried out in all TS cases and not be limited to virilised patients or carriers of a specific karyotype.

Association of immunohistochemical markers with premalignancy in Gonadal Dysgenesis

Background

Gonadal dysgenesis (GD) is associated with increased risk of gonadal malignancy. Determining a patient’s risk and appropriate timing of gonadectomy is challenging, but immunohistochemical markers (IHM) may help establish the diagnosis of malignant germ cell tumors (GCT). Our objective was to identify the prevalence of specific IHM expression in patients with GD and determine if the patterns of expression can help identify malignancy versus pre-malignancy state. We evaluated the published literature using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) system to provide recommendations on the predictive role of IHM in the detection of germ cell malignancy.

Methods

The data for this retrospective study included karyotype, gonadal location, external masculinization score, age at time of gonadectomy or biopsy, microscopic description and diagnosis of gonadal tissue, and immunohistochemical staining, including octamer binding transcription factor (OCT) 3/4, placental-like alkaline phosphatase (PLAP), β-catenin, alpha-fetoprotein (AFP), and stem cell factor receptor CD117 (c-KIT). Patients with complete or partial GD who had undergone gonadectomy or gonadal tissue biopsy were included.

Results

The study included 26 patients with GD, 3 of whom had evidence of GCT (11.5 %, gonadoblastoma, dysgerminoma): 2 had Swyer syndrome, 1 had 46,XY partial GD. One patient with XY partial GD had gonadoblastoma-like tissue. All 4 patients (15 %) had strong expressions of 4 tumor markers (OCT 3/4, PLAP, β-catenin, CD117), as did 5 other patients (19 %, ages 2–14 months) without GCT: 4 had XY GD, 1 had 46,XX GD. β-catenin was expressed in 96 % of patients in a cytoplasmic pattern, CD117 in 78 %, OCT 3/4 in 55 %, PLAP in 37 %, and AFP in 1 patient (4 %). Tumor marker expression was not specific for ruling out malignancy in patients <1 year.

Conclusions

In patients older than 1 year, expression of all three markers (OCT 3/4, PLAP, CD117) may be instrumental in the decision-making process for gonadectomy, even in the absence of overt germ cell malignancy. Our literature review suggests that OCT 3/4 expression is most helpful in predicting risk of malignancy. Additional criteria are needed to stratify risk in patients younger than 1 year of age, as these markers are not reliable in that age group.

Gonadoblastoma in patients with Ullrich-Turner syndrome

Ullrich-Turner syndrome (UTS) is a common chromosomal abnormality caused by partial or complete X chromosome monosomy. One half of the patients have a 45,X karyotype, whereas the remaining patients display other X chromosome anomalies. In 6% to 11% of UTS, a normal or partly deleted Y chromosome has been found. A 10% to 30% risk of developing gonadoblastoma was found in the latter patients. The aim of this study was to evaluate the prevalence of Y chromosome-derived material, the occurrence of gonadoblastoma, and the incidence of possible neoplasms in patients with UTS. Of 217 patients studied with UTS and chromosome analysis of peripheral-blood lymphocytes, Y chromosome material was found in 20 patients. Fluorescence in situ hybridization (FISH) testing was performed to characterize the structurally abnormal Y chromosome in 13 cases. Molecular analysis of the SRY gene could only be performed in 20 patients with 45,X karyotype. Two patients had the SRY genomes. Of the 20 patients with Y chromosome-derived material, 17 underwent gonadectomy. The incidence of gonadoblastoma development in our series was 35.5%. Furthermore, 1 patient also showed a pure dysgerminoma, and another showed a mixed dysgerminoma and embryonal carcinoma. We emphasize the importance of complete processing of the gonadectomy specimen, including step sections, molecular studies, and FISH, in addition to the classic cytogenetic searching for Y chromosome sequences, in patients who present with a nonmosaic 45,X karyotype. Finally, we propose to routinely collect a sample for storage in the tumor bank for future studies.

[The use of FISH on buccal smear to investigate mosaicism with a 45,X cell line: study on healthy men and patients with disorders of sex development]

OBJECTIVE

To verify whether fluorescence in situ hybridization (FISH) of cells from the buccal epithelium could be employed to detect cryptomosaicism with a 45,X lineage in 46,XY patients.

SUBJECTS AND METHODS

Samples of nineteen 46,XY healthy young men and five patients with disorders of sex development (DSD), four 45,X/46,XY and one 46,XY were used. FISH analysis with X and Y specific probes on interphase nuclei from blood lymphocytes and buccal epithelium were analyzed to investigate the proportion of nuclei containing only the signal of the X chromosome.

RESULTS

The frequency of nuclei containing only the X signal in the two tissues of healthy men did not differ (p = 0.69). In all patients with DSD this frequency was significantly higher, and there was no difference between the two tissues (p = 0.38), either.

CONCLUSIONS

Investigation of mosaicism with a 45,X cell line in patients with 46,XY DSD or sterility can be done by FISH directly using cells from the buccal epithelium.

Hidden Y Chromosome Mosaicism in 48 Egyptian Patients with Turner’s Syndrome

Background. The presence of Y chromosome material in Turner's syndrome (TS) patients is a risk factor for the development of gonadoblastoma. Although conventional cytogenetic analysis is the definitive diagnosis of TS, low level Y chromosome mosaicism may be missed. Molecular analysis has demonstrated a higher proportion of mosaicism, but there is controversy regarding the prevalence of Y chromosome-derived material in those patients. Aim and Methods. This study was conducted to investigate the prevalence of hidden Y chromosome mosaicism in 48 TS Egyptian patients using polymerase chain reaction (PCR) for molecular DNA analysis of SRY gene and compare our results with those in the literature. Results. None of TS patients had a cytogenetically obvious Y chromosome; Y chromosome material was detected only at molecular analysis. SRY gene was found in 9 TS patients (18.75%) with the classical 45,X karyotype, whereas all other patients were SRY negative. Conclusion. Cytogenetically undetected Y chromosome mosaicism is common in TS patients; these data reinforce the need for adequate diagnosis of Y chromosome material in those patients. Molecular screening for Y chromosome-derived DNA should be routinely carried out in all TS patients.

Gonadoblastoma: Case report of two young patients with isochromosome 12p found in the dysgerminoma overgrowth component in one case

Gonadoblastomas are unusual neoplasias that frequently appear in the dysgenetic gonads of women with chromosome Y anomaly. We present two cases of gonadoblastoma associated with complete gonadal dysgenesis and Turner syndrome, respectively, with dysgerminoma overgrowth found in one case. We were interested in the DNA ploidy, the presence of Y chromosome DNA sequence and the status of chromosome 12p arm among the tumor cells. We performed cytophotometry to analyze the DNA content and fluorescence in situ hybridization (FISH) to identify the Y chromosome and the isochromosome 12p within the tumor cells. The cytophotometric result showed diploid DNA content in gonadoblastoma, whereas dysgerminoma revealed aneuploid DNA. The FISH result revealed Y chromosome DNA sequence within gonadoblastoma and dysgerminoma. Isochromosome 12p was identified in dysgerminoma, but not in gonadoblastoma. We conclude that gonadoblastoma and dysgerminoma have a strong association with the Y chromosome, and dysgerminoma overgrowth is due to further chromosomal aberrations, such as isochromosome 12p. Histological, immunohistocheimcal and molecular studies should render the correct diagnosis. Identifying dysgerminoma overgrowth is crucial since it is associated with adverse prognosis and requires additional therapy.