在不孕症檢查中發現睪丸Leydig細胞腫瘤：個案報告

陳浩恩 ¹  曹智惟² 孫光煥²  

¹ 國防醫學大學國軍臺中總醫院外科部泌尿外科

² 國防醫學大學三軍總醫院外科部泌尿外科

Leydig Cell Tumor of the Testis Presenting During Infertility Workup: A Case Report  

Chun‑Ping Huang¹, Chi-Wei Tsao², Guan-Huan Sun²

¹ Division of Urology, Department of Surgery, Tri-Service General Hospital, National

Defense Medical University, Taipei 114024, Taiwan, ROC

² Division of Urology, Department of Surgery, Tri-Service General Hospital, National

Defense Medical University, Taipei 114024, Taiwan, ROC

Introduction:

Leydig cell tumors represent 1–3% of all testicular tumors and originate from the interstitial cells responsible for testosterone production. Although most are benign, a minority can exhibit malignant behavior. Clinical presentation varies widely, ranging from gynecomastia and sexual dysfunction to incidental detection during infertility evaluations. Given their rarity and nonspecific features, diagnosis requires careful integration of imaging, endocrine studies, and histopathology.

Case Presentation:

A 38-year-old married man without systemic disease was referred for evaluation of infertility. He had been undergoing assessment for in vitro fertilization when oligospermia was identified. The patient denied systemic symptoms such as weight loss, fatigue, fever, or changes in libido, and he reported no testicular pain or swelling. On physical examination, both testes were small (right 2.6 cm, left 3.3 cm) but without palpable nodules or tenderness. External genitalia were otherwise normally developed, and there were no signs of gynecomastia.

Scrotal ultrasonography revealed a well-circumscribed, heterogeneous hypoechoic lesion with internal vascularity, measuring 1.7 cm in the left testis. Hormonal studies demonstrated suppressed FSH and LH with elevated testosterone, while serum tumor markers, including β-HCG, were within normal limits. MRI of the brain excluded pituitary or hypothalamic pathology. The patient subsequently underwent a left radical orchiectomy. The resected specimen contained a 2.0 × 1.4 cm well-defined brown tumor confined to the testis. Histopathology confirmed a Leydig cell tumor. The postoperative course was uneventful, and the patient was discharged on the following day. Follow-up imaging and laboratory studies have shown no recurrence to date.

Discussion:

The evaluation of a testicular mass accompanied by hormonal abnormalities requires careful consideration of several differential diagnoses. Germ cell tumors are the most common testicular neoplasms but were less likely in this patient due to normal tumor markers and imaging findings. Adrenal rest tumors, Sertoli cell tumors, and other sex cord–stromal tumors were also considered. The patient’s elevated testosterone with suppressed gonadotropins suggested a functioning stromal tumor, and histology provided definitive confirmation of a Leydig cell tumor.

Although most Leydig cell tumors follow a benign course, malignant transformation is reported in approximately 5–10% of cases, typically presenting with larger tumor size, nuclear atypia, or evidence of metastasis. In this case, the tumor was small, confined to the testis, and without worrisome histologic features, indicating a favorable prognosis. An important clinical aspect is the association with impaired spermatogenesis. The patient’s infertility and oligospermia were likely related to hormonal dysregulation caused by the tumor, underscoring the need to evaluate endocrine parameters when infertility coexists with a testicular lesion.

Conclusion:

This case highlights the significance of Leydig cell tumors as a rare but clinically relevant cause of male infertility. Early recognition, thorough diagnostic workup, and timely surgical intervention are essential to achieving favorable outcomes. Radical orchiectomy remains the standard treatment, offering both diagnostic and therapeutic benefit. Long-term surveillance is still necessary, given the small but real risk of recurrence or malignant transformation.