Mandibular Osteolytic Lesion Associated with Exuberant Hyaline Ring Granuloma Reaction

Paradental cyst with hyaline ring granuloma masquerading as pericoronitis

Paradental cyst is an odontogenic cyst associated with pericoronitis in partly erupted mandibular third molars. It is an inflammatory cyst common among the mandibular molars. The cyst is most commonly seen on the distal or distobuccal aspect of the third molars. The angle of tooth and food impaction has been postulated to be responsible for the development of the cyst in third molars. The source of the epithelium has been reported as reduced enamel epithelium. The paradental cyst is frequently misdiagnosed as a radicular cyst or dentigerous cyst. We report a case of paradental cyst in a patient with partially erupted mandibular third molar with food impaction and resulting hyaline ring granuloma.

Hyaline ring granuloma of the mouth-A foreign-body reaction that dentists should be aware of: Critical review of literature and histochemical/immunohistochemical study of a new case

Hyaline ring granuloma (HRG) is a rare and atypical foreign-body granulomatous chronic inflammatory condition. Our aim was to make a critical review of the literature cases and also to illustrate histochemical and immunohistochemical findings of a new case. A modified PICO strategy was used. Inclusion criteria were met by case reports and case series with a histologically confirmed diagnosis of HRG, necessarily in mouth or maxillary bones. Exclusion criteria were no access to the full-text paper. The search was done up to 2019, totalizing 231 selected cases in 54 papers. The new case was analyzed through PAS, Azan-Mallory's trichrome, and CD34 and CD68 reactions. HRG is found mainly in the mandible of men, edentulous and prosthesis users, between 51 and 60 years of age, with 0.5-120 months of duration, usually causing edema and pain or discomfort. Endogenous and exogenous theories may be complementary in HRG. Eosinophilic areas could represent particles of vegetal origin, while the hyaline material could be the result of collagen degradation. Considering the material is not always present or even is ring-shaped, we suggest the change from "hyaline ring granuloma" to "granuloma induced by vegetal inoculation."

Osseous oral hyaline ring granuloma mimicking a mandible tumor in a child with congenital agenesis of the corpus callosum

BACKGROUND

Hyaline ring granuloma (HRG) of the oral cavity is an uncommon disorder considered to be a foreign-body reaction resulting from implantation of food vegetable particles. Microscopically, it is characterized by the presence of structures of hyaline rings in an inflamed fibrous tissue background, which contains multinucleated giant cells.

MATERIAL AND METHODS

We present the case of a 4-year-old boy diagnosed with a mandible osseous HRG, which showed clinical and tomographic aspects suggestive of an aggressive bone tumor.

RESULTS

The patient underwent surgical exploration and histopathologic analysis showed fragments composed predominantly of widespread dense connective tissue with an acute and chronic inflammatory infiltrate containing multinucleated giant cells and scattered areas of eosinophilic material associated with hyaline rings, strongly suggestive of vegetable particles. The eosinophilic material was positive for periodic acid-Schiff (PAS) and resistant to diastase digestion. These features led to diagnosis of osseous HRG. Scanning electron microscopy (SEM) analysis was performed for illustrative purposes and the multiple structures resembling vegetable particles were characterized in more detail.

CONCLUSIONS

Although rare, this case highlights the importance of the clinician's awareness regarding the existence of an osseous counterpart of HRG. Key words:Agenesis of the corpus callosum, child, hyaline ring granuloma, intraosseous, mandible, pulse granuloma.