The results document a substantial tumor yield in the selected surgical subgroup, although they do not establish an incidence for all children with the condition. Thirteen patients were admitted to the Department of Urology at the Children’s Hospital of Soochow University in Suzhou, China, between January 2016 and October 2023, and two additional patients were treated at the Qinghai Provincial Maternal and Child Health Hospital in Xining. Inclusion required a mosaic karyotype containing 45,X/46,XY cell lines and a normal female phenotype without ambiguity of the external genitalia.

The 13 Soochow patients underwent bilateral gonadectomy with salpingectomy, while the two Qinghai patients were followed in outpatient care without surgery. At the end of follow-up, the cohort had a mean age of 12.58 ± 3.02 years and a mean follow-up duration of 47.33 ± 30.78 months. Short stature or growth retardation was the main reason for the initial consultations.

Mean height rose from 124.39 ± 17.43 cm at presentation to 139.09 ± 17.76 cm at final follow-up. None of the children had signs of hyperandrogenism, including acne, hirsutism or virilization, and all had a Prader grade of 0 for external genital development. Three patients experienced menarche before gonadectomy.

Ultrasonography showed a rudimentary uterus and bilateral ovarian dysgenesis or streak gonads in every participant, and no definitive family history was reported. The uniformly female-appearing external phenotype therefore coexisted with internal gonadal dysgenesis and Y-containing cell lines. Peripheral-blood karyotyping established the diagnosis in nine children, accounting for 60% of the cohort, while fluorescence in situ hybridization, or FISH, detected the condition in the remaining six, or 40%.

The authors noted that a low percentage of mosaicism may become apparent when too few cells are tested or an inadequate number of tissues is sampled. On that basis, they considered supplementary molecular cytogenetic testing, including FISH and array-based diagnostics, useful when structural abnormalities of the sex chromosomes are identified. The present study did not perform systematic molecular analysis across all tissues, however, so the distribution of 45,X and 46,XY cells beyond the sampled material remained uncertain.

Pathological examination of the 13 surgical specimens found gonadoblastoma in four, or 30.77%. Three of these children had bilateral gonadoblastoma, while one had a lesion in the left gonad and a streak gonad on the right. The other nine operated patients had bilateral streak gonads without gonadoblastoma.

The reported ages of children with tumors ranged from 6.17 to 12.83 years, indicating that lesions were diagnosed across a substantial portion of childhood in this cohort. These observations cannot define a safe age threshold because the sample was small, follow-up was limited, and the two conservatively managed children provided no histological evidence about whether their gonads contained tumors. Gonadoblastoma was described in the research as a benign tumor composed of undifferentiated cells resembling those involved in gonadal development together with sex-cord derivatives.

The paper notes that it may develop into invasive dysgerminoma and can progress to other malignant germ-cell tumor types, while also citing no documented cases of metastatic disease or mortality attributed to gonadal malignancy in people with Turner mosaic syndrome containing Y material. The authors regarded the generally favorable prognosis as relevant to decisions about surgery, but the present youngest tumor at 6.17 years means that favorable outcomes observed elsewhere do not establish that an individual young child is free of risk. Before removal of dysgenetic gonads, the study’s management pathway included endocrine evaluation of gonadal function.

Measurements covered follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone and anti-Müllerian hormone. When clinically warranted, the investigators also used human chorionic gonadotropin and luteinizing hormone-releasing hormone stimulation tests, followed by gonadal biopsy in the described clinical approach. Retaining the gonads may permit spontaneous puberty, menstruation and possible fertility, but this potential benefit must be weighed against the tumor risk.

The authors’ conclusion favored prophylactic gonadectomy after an appropriate age while allowing postponement with regular monitoring in selected cases, emphasizing participation by patients in the decision rather than surgery at a single fixed chronological point. The two children managed without surgery underwent annual assessment using ultrasonography of the uterus and ovaries, serum biochemistry, a sex-hormone panel and measurement of growth hormone levels. Such surveillance could track anatomy and endocrine status but could not directly establish the presence or absence of gonadoblastoma, because neither patient had histological examination.

The retrospective design also meant that surgery and observation were not assigned randomly, and the two centers followed different management pathways. These features limit causal comparisons between the groups and make the 30.77% figure best interpreted as the histological yield among the 13 operated children rather than a universal population incidence. Twelve of the 15 children, or 80%, received growth hormone therapy at an initial dose of 0.15 IU/kg/day, which continued until the investigators considered the achieved height satisfactory.

The authors proposed considering discontinuation when growth potential was limited, including situations in which bone age exceeded 14 years or height gain fell below 2 cm per year. This growth-focused treatment was separate from gonadal management, and the observational design did not establish that gonadectomy produced the observed height increase. Overall, the study documents how karyotyping and FISH can identify Y-chromosome material in children with a female-appearing phenotype, records gonadoblastoma in 30.77% of those undergoing gonadectomy, and places surgery within an individualized assessment of endocrine function, tumor risk, reproductive potential and patient participation.

Published rates of gonadoblastoma in other small retrospective series have ranged widely, including 12% in a review of 43 patients, 28.6% in 14 patients, 35.5% in 20 patients, 10% in 10 patients and 57.1% in seven patients. Those figures are not directly interchangeable with the present result because sampling, follow-up and pathological assessment differed, and small retrospective cohorts are vulnerable to selection bias. The authors acknowledged their own study’s retrospective design, small sample and incomplete tissue-level molecular analysis.

Within those limits, the evidence shows that Y-chromosome material may be present despite a female-appearing phenotype, that karyotyping and FISH each contributed to diagnosis, and that dysgenetic gonads require endocrine evaluation and carefully individualized decisions about surveillance, gonadectomy and involvement of the patient and family.

Subject of Research: Clinical characteristics, diagnosis, gonadal pathology and management of Turner mosaic syndrome with Y-chromosome material in children.

Article Title: Turner mosaic syndrome with Y chromosome material: characteristics, diagnosis, and management

Article References: Wang, T., Zeng, G., Cao, X., Xia, H., Zhang, T., Yan, X., & Fu, M. (2026). Turner mosaic syndrome with Y chromosome material: characteristics, diagnosis, and management. Frontiers in Pediatrics, 14, Article 1948778. https://doi.org/10.3389/fped.2026.1948778

Image Credits: AI Generated

DOI: 10.3389/fped.2026.1948778

Keywords: Turner mosaic syndrome, Y chromosome, gonadoblastoma, gonadectomy, pediatric urology, FISH, karyotyping, gonadal dysgenesis, endocrine monitoring, retrospective cohort, Turner, mosaic