testis_chapter

Testis and Testicular Adnexa Prognosis

• Testicular germ cell tumors are highly curable solid cancers in men.

  • Cure Rates:

    • Close to 100% for stage I tumors (seminoma and non-seminoma).

    • High cure rates remain for metastatic cases, varying by prognostic group.

  • Salvage Therapy:

    • Can cure over 50% of patients with initial treatment failures.

  • Later Relapses:

    • Less common and may indicate adverse prognosis, especially with secondary malignancies.

Noninvasive Germ Cell Neoplasia (GCNIS)

• Also known as Intratubular Germ Cell Neoplasia, Unclassified.

  • WHO 2016 classification promotes the term Germ Cell Neoplasia in Situ (GCNIS).

• Prevalence:

  • Frequently seen in residual testis after invasive germ cell malignancies (over 80% in some cases).

  • Present in about 5% of contralateral testicles in patients with testicular tumors.

• Characteristics:

  • Uniform appearance regardless of invasive germ cell component.

  • Typically localized to seminiferous tubules but can extend to rete testis with a pagetoid appearance.

  • Recognized as a precursor to invasive disease, with a 50% progression rate to invasive disease within 5 years.

  • Histologically identifiable by atypical germ cells at the base of seminiferous tubules.

Metastatic Behavior of Testicular Tumors

• Spreads first to periaortic and iliac lymph nodes, then to mediastinal and left supraclavicular nodes.

• Retroperitoneal Metastases:

  • Usually on the tumor side (80%-86%).

  • Bilateral in 13%-20% of cases.

  • Typically found beneath renal vessels.

• Blood-Borne Metastases:

  • Common in lungs, liver, brain, and bone.

  • Specific tendencies:

    • Brain metastases in choriocarcinoma.

    • Bone metastases in seminoma.

• **Tumor Types:

  • Teratomas post puberty can metastasize regardless of differentiation.

  • Classic seminomas generally remain consistent in appearance upon metastasis.

  • Mixed germ cell tumors with seminomatous components are more likely to metastasize.

Treatment of Testicular Germ Cell Tumors

• Initial Treatment:

  • Inguinal orchiectomy with high ligation of the spermatic cord.

• Post-Orchiectomy Treatment:

  • Evolving approaches include options for chemotherapy, surgery, or active surveillance based on the stage and type.

  • Stage I tumors: Sometimes treated with orchiectomy alone unless relapse occurs.

  • Stage II: Often treated with orchiectomy and retroperitoneal lymphadenectomy, with chemotherapy reserved for relapsed patients.

  • Controversial surveillance in high-risk cases, though high cure rates still viable.

• Biopsy Considerations:

  • Contralateral testis biopsy for GCNIS is debated, with no uniform practice.

Specific Forms of Intratubular Germ Cell Neoplasia

• GCNIS:

  • Dominant noninvasive type but may have other components mixed with invasive disease.

• Intratubular Seminoma:

  • Atypical germ cells replace normal cells, sometimes with syncytiotrophoblasts associated with invasive malignancy.

• Intratubular Embryonal Carcinoma:

  • Comprised of malignant cells with central necrosis; may be confirmed by immunoreactivity for CD30.

Seminoma and Embryonal Carcinoma

• Seminoma:

  • Comprises 30%-40% of testicular tumors, characterized by a solid, homogeneous appearance, often yellow to tan.

  • Varied architectural patterns and the presence of syncytiotrophoblastic giant cells (10%-20% of cases).

• Embryonal Carcinoma:

  • More heterogeneous appearance with foci of hemorrhage and necrosis.

  • Diagnosed based on distinct histological features including anaplastic cells and prominent nucleoli.

Post-Pubertal Teratoma

• Classification:

  • Divided into prepubertal and post-pubertal subtypes as per WHO criteria.

  • All post-pubertal teratomas are considered malignant regardless of morphology.

• Characteristics:

  • Cystic, multiloculated structure with potential components of various tissue types (e.g., neural, cartilage).

• Presence of primitive neuroepithelial tissue may resemble neuroblastoma; must apply criteria for somatic-type malignancy to classify appropriately.