Intracytoplasmic eosinophilic hyaline globules in cartilaginous neoplasms: A surgical, pathological, ultrastructural, and electron probe x-ray microanalytic study

Abstract Hyaline globules (HGs), spherical intracytoplasmic eosinophilic droplets, have been associated with a variety of conditions, including hepatocellular carcinoma, lung adenocarcinoma, and Kaposi's sarcoma, but they have not been described in cartilaginous tumors. In specimens of 60 cartilaginous neoplasms we found that 22 of 33 chondrosarcomas (67%), eight of 16 enchondromas (50%), and three of seven soft tissue chondromas (43%) exhibited HGs. HGs were seen more commonly in low grade chondrosarcoma (70%) and were relatively rare in high grade chondrosarcoma (25%). No HGs were identified in three osteochondromas, one synovial chondromatosis, or 15 normal cartilaginous tissues taken from various sites. Cartilage associated HGs ranged in size from 2 to 20 μm, were diastase resistant and periodic acid-Schiff (PAS) stain positive, demonstrated autofluorescence, and variably stained with Mallory's phosphotungstic acid-hematoxylin stain (PTAH). A panel of immunostains did not show any specific staining reactions with HGs. Ultrastructurally the HGs were spherical, non-membrane-bound bodies having complex architectural features associated with profiles of rough endoplasmic reticulum. Electron probe x-ray microanalytic (EPXMA) study showed significant peaks of sulphur and calcium. We conclude that HGs represent secretory products of probable glycoprotein nature, may accumulate in a variety of cartilaginous neoplasms, and may be seen more frequently in low grade chondrosarcomas.