Cartilage-Producing Lesions

Abstract

Tumors that produce a chondroid matrix are traditionally grouped together regardless of their histogenesis. There are three types of cartilage: hyaline cartilage, fibrocartilage, and elastic cartilage. In the adult, hyaline cartilage is present in the joints; fibrocartilage is mostly found in the spine; and elastic cartilage is seen in the external ear, epiglottis, and a few other places. The vast majority of cartilaginous matrix encountered in frozen sections is hyaline cartilage, which is easily recognizable based on its amorphous basophilic quality. Mature chondrocytes reside within sharp-edged lacunar spaces embedded in the matrix and have finely granular eosinophilic cytoplasm that is often vacuolated. The nuclei are typically small and round with condensed chromatin (“tight nuclei”). The nuclear detail is usually not appreciated. The presence of small clusters of chondrocytes, more than one cell per lacuna, and occasional binucleation is not uncommon. Mitotic activity is usually not discernable.