A novel perspective on dissemination: somatic metastasis of germ cell tumors from the central nervous system.

Purpose: Primary germ cell tumors (GCTs) of the central nervous system are rare malignancies, with somatic metastasis being even less common. This study aims to propose a novel classification framework for dissemination patterns in CNS GCTs.

Methods: A group of 4 patients with somatic metastasis were identified among 284 germ cell tumors. The characteristics of patients were identified through clinical history, imaging, and histopathology. Hematoxylin-eosin (H&E) and Immunohistochemistry (IHC) confirmed the pathological features, while radiology was used to determine the temporal and spatial characteristics of metastasis. Univariate analysis was conducted to assess the factors contributing to abdominal spread. Fisher's exact test was used for categorical data analysis. The dissemination process was systematically analyzed.

Results: This disease is extremely rare, and the progression of metastatic germ cell tumors is often complex. All four patients underwent surgery, radiotherapy, and chemotherapy. In one case, the tumor spread to the anterior superior mediastinum via hematogenous metastasis; in two cases, it spread to the abdominal cavity through a ventriculoperitoneal shunt; and in one case, intraspinal spread occurred via cerebrospinal fluid. Over a follow-up period of 9 to 67 months, only one patient died from the disease. H&E and IHC staining confirmed pathological features. Analyzing dissemination introduced concepts like dynamics, components, mediums, ranges, portals, and patterns, creating a framework for understanding disease spread.

Conclusion: Our findings offer valuable insights for guiding treatment strategies and improving patient outcomes. CNS GCTs can be managed effectively with accurate diagnosis and appropriate treatment. The introduction of new concepts and classifications of dissemination can inform and guide treatment strategies.