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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.