An Ultrastructural Study of Mineralization in Craniopharyngiomas

Does the calcification of adamantinomatous craniopharyngioma resemble the calcium deposition of osteogenesis/odontogenesis?

“…The wet keratin, also called ghost cell structure, derives from degenerative whorl-like array cell nests and is thought to be the fundamental structure of calcification. 5 Consistent with this model, H&E staining revealed osteoblast-like cells of varying shape in the calcification lesions arising from the wet keratin, which also implies a possible biological similarity to differentiating osteoblasts in bone. 51 Hence, our morphological assessment and the location of these two osteoblast-specific transcription factors shown here using immunohistochemistry were consistent, and these findings are also consistent with ultrastructure research showing cells with morphology similar to osteoblasts in the area of the wet keratin.…”

“…Of note, Runx2 and Osterix were also present in the epithelia in/around the wet keratin and calcification lesions. The wet keratin, also called ghost cell structure, derives from degenerative whorl‐like array cell nests and is thought to be the fundamental structure of calcification . Consistent with this model, H&E staining revealed osteoblast‐like cells of varying shape in the calcification lesions arising from the wet keratin, which also implies a possible biological similarity to differentiating osteoblasts in bone .…”

“…Histologically, ACP resembles some odontogenic tumours with characteristics including calcification, peripheral palisades, stellate reticulum, whorl‐like array cells, wet keratin and cholesterol clefts, none of which are observed in SPCP . Importantly, the whorl‐like array cells and their derivative, the wet keratin, have been recognized as the fundamental structure for the formation of calcification …”

“…4 Importantly, the whorl-like array cells and their derivative, the wet keratin, have been recognized as the fundamental structure for the formation of calcification. 5 The generation of organic matrix elements and their mineralization is a common process for hard structures. In bone and teeth, osteoblasts and odontoblasts secrete organic matrix such as collagen, glycoproteins and proteoglycans, accompanied by calcium salts and crystal deposits.…”

The role of matrix vesicles in growth plate development and biomineralization

“…Lipper et al showed that extracellular vesicles, formed from intact human meningioma cells, were associated with psammoma bodies and appeared instrumental in the calcification of extracellular material in vitro (173). In an ultrastructural study of mineralizing craniopharyngiomas, needle-shaped crystals similar to hydroxyl-apatite were found in membrane bound vesicles morphologically similar to matrix vesicles (174). Similar findings were seen in oligodendrogliomas (175), and arachnoid villi (176).…”