fibroskapsel

Fibroskapsel, or fibrous capsule, is a tough layer of dense connective tissue that surrounds and protects various organs, joints, or lesions. It is mainly composed of collagen fibers produced by fibroblasts. The capsule defines boundaries, provides mechanical stability, and helps to limit spread of inflammatory or neoplastic processes.

In joints, the fibrous capsule forms the outer part of the articular capsule (capsula fibrosa) and is continuous with the periosteum. It is organized into a thick, collagen-rich outer layer that blends with ligaments and an inner synovial membrane that secretes synovial fluid.

In tumors or cystic lesions, a fibrous capsule may develop as the lesion grows, created by compression of surrounding tissue and fibroblastic activity. A well-formed capsule can aid surgical excision and imaging, but invasion of the capsule by malignant cells may occur, indicating a more aggressive disease.

Examples of fibrous capsules include the renal capsule surrounding the kidney and Glisson's capsule enclosing the liver; the outer, tough layer of a synovial joint is also a fibrous capsule. The concept emphasizes the capsule’s role in protection, boundary formation, and potential influence on disease progression and treatment.