Seminoma in a 46, XY patient with 17α‐hydroxylase deficiency

Introduction 17α‐Hydroxylase deficiency is a very rare disease reported to be associated with a risk of gonadal malignancy. We herein report a rare case of seminoma in a 46, XY patient with 17α‐hydroxylase deficiency. Case presentation A 52‐year‐old woman presented with a 9‐cm pelvic tumor. At age 14, she had been identified as having the XY karyotype and 17α‐hydroxylase deficiency. However, she was not informed and did not consult the urology department. Laparoscopic gonadectomy was performed at the latest consultation, and seminoma was diagnosed. Conclusion This is the third reported case of testicular tumor and the first of germ cell tumor in a 46, XY patient with 17α‐hydroxylase deficiency. Given the rarity and the risk of gonadal malignancy associated with 17α‐hydroxylase deficiency, the involvement of multidisciplinary specialists and prophylactic gonadectomy is considered crucial in its management.