Non-Germ Cell Tumours & Tumours of the Testicular Adnexa

Non-germ cell testicular tumours

• Non-Germ Cell Tumours comprise 5% of testicular tumours (95% are of Germ Cell Tumours)

Sex-cord stromal tumours

• Refers to neoplasms containing Leydig cells, Sertoli cells, granulosa cells, or thecal cells.
• ≈90% are benign, 10% are malignant
  • Presence of metastatic disease is the only reliable criterion for establishing malignancy
    • Most frequent metastatic sites are the retroperitoneum and lung
• Leydig cell tumours
  • Account for 75-80% of sex cord–stromal tumors
  • Most occur in men 30-60 years old
  • No association with cryptorchidism
  • ≈10% are bilateral (more common than GCT)
  • May be associated with gynecomastia (similar to GCT)
  • Radical inguinal orchiectomy is the initial treatment of choice (similar to GCT)
    • If the diagnosis is suspected preoperatively, given the 90% incidence of benign histology, testis-sparing surgery may be considered for lesions less than 3 cm with intraoperative frozen-section histologic confirmation.
      • Completion orchiectomy should be performed if GCT histology is seen (either on intraoperative frozen section or on final pathology) or if malignant features are present on final pathologic examination of the resected tumor
  • Persistent Leydig cell dysfunction and hypogonadism may occur after excision of the primary tumor, and 40% of men may require testosterone supplementation postoperatively
• Sertoli cell tumours
  • As with Leydig cell tumors, testis-sparing surgery can be considered for tumors less than 3 cm given the high incidence of benign histology (90%).
• Granulosa cell tumours
  • Exceedingly rare
• Gonadoblastoma
  • Occur almost exclusively in patients with gonadal dysgenesis and intersex syndromes.
  • Bilateral orchiectomy is required because of the 40% risk of bilateral tumors

Miscellaneous Testis Neoplasms

• Dermoid and epidermoid cysts
  • “Onion peel” appearance on ultrasound scan.
  • Insert figure
  • Enucleation or partial orchiectomy may be performed, although the lesion should be thoroughly sampled by a pathologist to rule out GCT or ITGCN

Adenocarcinoma of the rete testis

• Rare but highly malignant neoplasm arising from the collecting system of the testis
• > 50% of patients present with metastatic disease, and the median overall survival is 1 year

Secondary tumours of the testis

• Lymphoma
  • Most commonly involves the testis through dissemination from extra-testicular sites.
  • 85% occur in men older than 60 years.
  • Non-Hodgkin lymphoma is the most common testicular neoplasm in men aged > 50
  • Bilateral testicular involvement occurs in 35% of cases.
  • The initial treatment is radical inguinal orchiectomy. Men with testicular non-Hodgkin lymphoma should be referred to a hematologist-oncologist
• Leukemic infiltration
  • The testis is a frequent site of relapse in boys with acute lymphocytic leukemia
  • Diagnosis can usually be made by biopsy, and orchiectomy is unnecessary. Local control can be achieved with low-dose radiotherapy and treatment should include the contralateral testis because of the frequent risk of bilateral involvement
• Metastases
  • The most common primary tumors are prostate, lung, melanoma, colon, and kidney

Tumours of the testicular adnexa

• Adenomatoid tumor
  • Most common paratesticular tumor
  • Most commonly involving the epididymis
  • Generally asymptomatic
  • Typically benign tumors, no reported cases of metastasis
  • Management: surgical excision.
• Cystadenoma
  • Approximately 1/3 of cases occur in patients with von Hippel-Lindau disease, which are usually bilateral
• Paratesticular mesothelioma
  • Arises from the tunica vaginalis
• Sarcomas of the spermatic cord, epididymis, and testis
  • Most common genitourinary sarcomas in adults
  • Liposarcoma is the most common histologic subtype in adults
  • Embryonal rhabdomyosarcoma is most common in men younger than 30 years of age.
  • Management: wide resection through an inguinal approach with excision of the testis and spermatic cord and high ligation.
    • Additional therapy is indicated by histologic subtype and the presence or absence of regional or distant metastases.
      • Liposarcomas rarely metastasize, but local recurrence is relatively common. As such, adjuvant radiotherapy should be considered for paratesticular liposarcoma, especially in cases where the adequacy of local excision is in doubt (positive margins or large tumors).
      • When metastatic evaluation is normal, patients with sarcomas other than liposarcoma (i.e., rhabdomyosarcoma, malignant fibrous histiocytoma, angiosarcoma) and mesothelioma should undergo RPLND, with postoperative chemotherapy if retroperitoneal lymph nodes

References

• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 34