China
Africa
Explore chapters and articles related to this topic
Craniopharyngioma
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Hermann L. Müller, Claire Alapetite, Jeffrey Wisoff
There are two craniopharyngioma subtypes: adamantinomatous and papillary craniopharyngiomas.36,37 Adamantinomatous craniopharyngioma is recognized by the presence of squamous epithelium arranged in cords, nodules, and irregular trabeculae bordered by palisaded columnar epithelium. These islands of densely packed cells merge with loosely cohesive aggregates of squamous cells known as stellate reticulum (Figure 18.1a). Nodules of “wet keratin” representing remnants of pale nuclei embedded within an eosinophilic keratinous mass are found in either the compact or looser areas. Cystic cavities containing squamous debris are lined by flattened epithelium. Granulomatous inflammation associated with cholesterol clefts and giant cells may be detectable, but this is more typical for xanthogranuloma. Piloid gliosis with abundant Rosenthal fibers is often seen at the infiltrative interface of the tumor and should not be mistaken for pilocytic astrocytoma. The question of “malignant transformation” of craniopharyngioma has been raised in the literature, but this appears to be very rare.25
ExperimentaL Oral Medicine
Published in Samuel Dreizen, Barnet M. Levy, Handbook of Experimental Stomatology, 2020
Samuel Dreizen, Barnet M. Levy
Dentigerous cysts are thought to arise after completion of crown formation by accumulation of fluid either within the layers of reduced enamel epithelium or between the epithelium and enamel surface. Some hold that such cysts develop outside the follicle and are penetrated by an erupting tooth; others believe that some dentigerous cysts originate as periapical cysts on deciduous teeth into which permanent tooth crowns intrude. There have also been suggestions that some dentigerous cysts begin their formation by degeneration within the stellate reticulum during enamel apposition.
Bone
Published in Joseph Kovi, Hung Dinh Duong, Frozen Section In Surgical Pathology: An Atlas, 2019
A 40-year-old man visited his dentist because of a painless swelling in his jaw of 6 months duration. The patient was referred to dental surgery. On palpation, a hard mass was felt in the angle of the mandible on the right side. Radiographs of the mandible revealed a mul-tilocular radiolucent lesion. A biopsy was performed and frozen section examination requested. Microscopically, varying sized epithelial islands were noted embedded in a loose, fibrous stroma. The central portion of the epithelial nests was made up of a loose network of fusiform cells, resembling the so-called stellate reticulum of the developing tooth bud. » The outermost layer of the epithelial islands consisted of a single row of tall, columnar cells, the nuclei of which were polarized away from the distinct basement membrane. These cells were similar to those found in the ameloblastic layer of the developing tooth follicle. Cystic degeneration of the central stellate reticulum was common (Figures 77 and 78).
Vacuolar protein sorting 4B regulates the proliferation and odontoblastic differentiation of human dental pulp stem cells through the Wnt-β-catenin signalling pathway
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Yuhua Pan, Ting Lu, Ling Peng, Zhao Chen, Meiyi Li, Kaiying Zhang, Fu Xiong, Buling Wu
To examine the expression and localization of VPS4B, we first performed immunohistochemical staining of the front sections of a murine first mandibular molar on PN1, PN3, PN5 and PN7 (Figure 1). We found that during dentin development (from PN1 to PN7), VPS4B was highly expressed in the dental pulp cells near odontoblasts. At the late bell stage (PN1), VPS4B was also mildly expressed in the stratum intermedium and odontoblasts and weakly expressed in the stellate reticulum (Figure 1A-a). At the stage of hard-tissue formation and mineralization (from PN3 to PN5), VPS4B was consistently expressed in dental pulp cells, preodontoblasts and the stratum intermedium (Figure 1B-b,C-c). In contrast, the cells of the stellate reticulum stained only weakly while the odontoblasts tested negative for VPS4B (no staining; Figure 1B-b,1C-c). When dentin was formed (PN7), VPS4B was intensely expressed in dental pulp cells (Figure 1D-d).
Osteocalcin, Azan and Toluidine blue staining in fibrous dysplasia and ossifying fibroma of the jaws
Published in Alexandria Journal of Medicine, 2018
Samuel Ebele Udeabor, Akinyele Olumuyiwa Adisa, Anna Orlowska, Poju Chia, Robert A. Sader, Shahram Ghanaati
Azan as earlier stated is a trichrome stain that uses three anionic dyes to mark different tissues histologically. It is an improvement over the traditional Mallory’s method and stains muscle fibers red and cartilage/bone matrix blue.8 A study on its use in ameloblastoma has demonstrated that it could differentiate the fibrous connective tissue from the stellate reticulum in all the variants of ameloblastoma stained. This is an improvement over the routine H and E staining.13
Human cytomegalovirus is present in the odontogenic epithelium of ameloblastoma
Published in Journal of Oral Microbiology, 2021
Mohammed Amjed Alsaegh, Sudhir Rama Varma, Alaa Muayad Altaie, Shengrong Zhu
HCMV-gB was immunohistochemically identified as a yellowish to brown precipitate that located mainly in the nucleus and less frequently in the cytoplasm of the studied odontogenic epithelial cells. The location of HCMV-gB expression was in both the peripheral columnar cells and stellate reticulum‒like cells of Abs, while positively stained cells in DC were located throughout the layers of the epithelial wall (Figure 1).