Conventional oncology models conceptualize the tumor capsule as a self-constructed shield by malignant cells. We propose a paradigm-shifting hypothesis: the solid tumor’s fibrotic barrier is primarily engineered by the host immune system as an emergency containment mechanism to restrict metastatic dissemination. This concept echoes the longstanding analogy of tumors as "wounds that do not heal," where the persistent fibrotic response mimics chronic wound healing processes driven by ongoing immune activation [Dvorak1986]. While protective, this barrier inadvertently creates a sealed biomechanical microenvironment characterized by elevated interstitial fluid pressure (IFP) and gas accumulation—key contributors to therapeutic resistance, including resistance to immunotherapy. This immune-constructed barrier also contributes to the classification of tumors as immunologically "cold," characterized by limited immune cell infiltration and poor response to immunotherapy. Here, we introduce a three-stage therapeutic protocol—decompression, infiltration and reprogramming (including immunotherapy integration), and extracorporeal purification—designed to leverage, rather than dismantle, this immune-constructed wall. By mechanically relieving internal pressure before intervention, we enable targeted drug delivery, cellular re-differentiation, and enhanced immunotherapy efficacy, while concurrent nanofilter-enhanced dialysis prevents systemic toxicity. This framework reframes solid tumor management from destruction to controlled reconditioning, with potential to convert "cold" tumors into more immunologically responsive states.