GCNIS
GCNIS, or germ cell neoplasia in situ, is a premalignant lesion of the gonads and the principal precursor to most testicular germ cell tumors, including seminoma and non-seminomatous germ cell tumors. It is believed to arise from gonocytes that fail to differentiate properly during fetal development and persists in the seminiferous tubules into puberty and adulthood. GCNIS cells are typically noninvasive but clonally related to invasive germ cell tumors, and their presence indicates a risk of progression to cancer if not monitored or treated.
Pathologically, GCNIS is characterized by atypical germ cells within the basement membrane of seminiferous tubules. These
Risk factors associated with GCNIS include cryptorchidism, testicular dysgenesis, infertility, and a family history of testicular
Clinical management depends on the clinical context. In men with known GCNIS, surveillance for progression to