Gonadal tumour risk in 292 phenotypic female patients with disorders of sex development containing Y chromosome or Y-derived sequence.

OBJECTIVE: Phenotypic female disorders of sex development (DSD) patients with Y chromosome or Y-derived sequence have an increased risk of gonadal germ cell tumours (GCTs). The objective of the study was to evaluate tumour risk of DSD, summarize the clinical characteristics of patients with GCTs and propose management suggestions.

METHODS: Medical records of 292 patients diagnosed DSD and undergoing bilateral gonadectomy at Peking Union Medical College Hospital from January 1996 to March 2016 were retrospectively reviewed. Tumour histopathological types, risks and clinical characteristics were evaluated.

RESULTS: The tumours in DSD included gonadoblastoma, seminoma, dysgerminoma, Sertoli cell tumour, yolk sac tumour and choriocarcinoma. The overall GCTs risk was 15·41% and 46, XY pure gonadal dysgenesis (46, XY PGD) carried the highest risk up to 23·33%, followed by complete androgen insensitivity syndrome (CAIS). The risk of mixed gonadal dysgenesis (GD) or 46, XY 17 alpha-hydroxylase/17, 20-lyase deficiency (46, XY 17 OHD) was <10%, and no tumour was found in five testis regression patients. The ages (years) of tumour diagnosed ranged from 11 to 29 [18 (15, 21) years]. The median age of androgen insensitivity syndrome (AIS) with tumours was comparatively late [19 (18, 24) years], while GCTs occurred during adolescence in 46, XY PGD [17 (15, 20) years] and mixed GD [15 (15, 17) years]. Sex hormone levels were generally unaffected by gonadal GCTs. The positive tumour marker rate before surgery was 58·82% (10/17). Elevated lactate dehydrogenase (LDH) was observed in six cases with dysgerminoma/seminoma. Remarkably elevated α-fetoprotein (AFP) or human chorionic gonadotropin (hCG) was seen in cases with yolk sac tumour or choriocarcinoma, respectively. Mild hyperandrogenism was observed in seven cases with GCTs. Fourteen of 17 pelvic masses found before operation was later proved malignant.

CONCLUSION: Disorders of sex development patients with Y chromosome materials have a significantly increased risk of GCTs. Gonadoblastoma and dysgerminoma/seminoma are the most prevalent GCTs and 46, XY PGD carries the highest tumour presence and malignancy risk. AIS could postpone bilateral gonadectomy until or after adolescence, while others with streak gonads should undergo surgery as soon as diagnosis. Specific serum tumour markers could be used in predicting GCTs and monitoring. Optimal care and close follow-up are required.