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.
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.
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.
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.
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:
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.
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.