Twenty years of experience with lesions involving the temporomandibular joint and adjacent structures complex.

With their close anatomical relationship, the temporomandibular joint (TMJ), mandibular ramus, skull base, ear, and infratemporal fossa make up a complex structure that may collectively be referred to as the 'TMJ and adjacent structures complex' (TASC). This study presents the neoplasms that may be encountered in the TASC region and their classification, which may be useful for the surgical treatment. Data of 1022 consecutive patients treated with resection of TASC neoplasms from May 2000 to October 2022 were reviewed. Pathology outcomes were classified according to the World Health Organization classification and Bone Tumors (Dorfman and Czerniak). Extent of the lesions was analysed based on imaging modalities. Ten tissue origins were observed. Synovial lesions accounted for the highest proportion of pathologies (56.0%). Regarding their biological behaviour, the lesions could be divided into pseudotumours (12.8%), benign tumours (28.4%), intermediate tumours (57.0%), or malignant tumours (1.8%). All lesions originated from one of four sites: lesions intrinsic to the TMJ (91.5%), extending from adjacent structures (7.7%), distant metastatic spread (0.4%), and multiple general foci (0.4%). In conclusion, it is hoped that knowledge of the histopathological and biological features will facilitate the surgical treatment of these pathologies in a rational, minimally invasive, and functional manner.