Testicular Germ Cell Tumors

Pathological and Clinical Characteristics

Seminoma and non-seminoma represent the two main histological subtypes of testicular germ cell tumors (TGCTs), with distinct biological behaviors and clinical features 1
Alpha-fetoprotein (AFP) is typically elevated in non-seminoma but never in pure seminoma; elevated AFP in a supposed "seminoma" indicates mixed histology with non-seminomatous elements 1

The International Germ Cell Cancer Collaborative Group (IGCCCG) classifies seminoma as either good or intermediate risk, while non-seminoma can be classified as good, intermediate, or poor risk 1
There is no poor-risk category for seminoma, reflecting its generally better prognosis 1
5-year survival rates for metastatic disease are 91%, 79%, and 48% for good, intermediate, and poor prognosis groups, respectively 1

Approximately 80% of seminoma patients present with stage I disease, with a survival rate of ~99% 2
Adjuvant options include single-dose carboplatin (AUC 7) or radiotherapy (20 Gy/10 fractions), with carboplatin showing similar relapse rates but fewer long-term side effects compared to radiotherapy 2
Risk stratification for non-seminoma is based on lymphovascular invasion - low risk (20% relapse rate) or high risk (40-50% relapse rate) 3
Adjuvant chemotherapy with 1-2 cycles of BEP (bleomycin, etoposide, cisplatin) is recommended for high-risk patients or those unable to comply with surveillance 3

Stage IIA (lymph nodes 1-2 cm): Treatment options include radiotherapy (30 Gy) or cisplatin-based chemotherapy 4
Stage IIB/IIC: Three cycles of BEP is standard therapy 4
Stage III: Three cycles of BEP for good prognosis; four cycles for intermediate prognosis 4
Post-chemotherapy residual masses >3cm require FDG-PET scan evaluation; negative PET predicts absence of viable tumor with >90% accuracy 5
Stage IIA marker-positive and IIB-III: Three cycles of BEP for good prognosis; four cycles of BEP for intermediate or poor prognosis 6
Post-chemotherapy management requires surgical resection of all residual masses >1cm, as these may contain viable tumor or teratoma 7

Late relapses (>2 years after treatment) occur in 2-3% of patients and are more difficult to treat, especially in non-seminoma 8
Non-seminoma late relapses often contain yolk sac tumor (AFP-positive) or teratoma elements and respond poorly to chemotherapy 8
Surgical resection plays a critical role in managing relapses, particularly for non-seminoma 8

Follow-up should focus on both relapse detection and monitoring for late treatment toxicity 8

Never assume pure seminoma with elevated AFP; this indicates non-seminomatous elements 1
Don't underestimate the importance of surgical resection of residual masses in non-seminoma, even with normal markers 7
Remember that PET scans are valuable for evaluating residual masses in seminoma but have limited utility in non-seminoma 5