Abstract

Introduction: Endochondral and membranous ossification is the fundamental physiological mechanism of bone growth; however, under certain conditions, it may be pathologically activated in extraosseous tissues. This phenomenon has been closely associated with chronic inflammation and altered tissue microenvironments and has been described in multiple anatomical locations, particularly in tissues with synovial physiology. In the cardiovascular system, calcification and ossification of structures such as cardiac valves, the fibrous skeleton and the development of the oss cordis represent clinical manifestations of similar biological processes.
Objective: To describe the histopathological features of benign extraosseous cartilaginous lesions associated with chronic inflammation in soft tissues and to explore their parallels with the mechanisms involved in cardiac calcification and ossification, including oss cordis formation.
Methods: A retrospective analysis was conducted on seven cases of benign extraosseous cartilaginous tumors with histological evidence of chronic inflammation. Specimens were processed using conventional histological techniques and evaluated by an experienced pathologist, focusing on patterns of chondrogenic differentiation and endochondral ossification.
Result: All cases demonstrated ectopic cartilaginous tissue with features consistent with organized endochondral ossification. Lesions were in synovial tissue, tendon sheath, skin and showed chronic inflammatory infiltrates in the surrounding stroma. Histopathological diagnoses included osteochondromatosis, cartilaginous fibroadipose tissue and chondromyxoid fibrous tissue.
Conclusions: Chronic inflammation emerges as a central factor in the aberrant activation of chondrogenic and osteogenic differentiation programs in soft tissues, leading to extraosseous endochondral ossification. Histopathological and molecular parallels with cardiac calcification and ossification suggest a shared etiopathogenic basis, with relevant implications for the development of therapeutic strategies targeting early stages of the process.

Keywords:Endochondral ossification; Extraosseous ossification; Chronic inflammation; Synovial tissue; Cardiac calcification; Oss cordis