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Year : 2023  |  Volume : 66  |  Issue : 2  |  Page : 435-437
Unusual encroachers in odontogenic keratocyst

1 Department of Oral Pathology and Microbiology, SRM Dental College, Chennai, Tamil Nadu, India
2 Department of Oral and Maxillofacial Surgery, SRM Dental College, Chennai, Tamil Nadu, India
3 Department of Oral Pathology, Saveetha Dental College, Chennai, Tamil Nadu, India

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Date of Submission13-Jan-2021
Date of Acceptance23-Mar-2021
Date of Web Publication02-Jun-2022

How to cite this article:
Divya B, Vasanthi V, Krishnan R, Krishna Kumar Raja V B, Kumar A R, Ramadoss R, Velavan K. Unusual encroachers in odontogenic keratocyst. Indian J Pathol Microbiol 2023;66:435-7

How to cite this URL:
Divya B, Vasanthi V, Krishnan R, Krishna Kumar Raja V B, Kumar A R, Ramadoss R, Velavan K. Unusual encroachers in odontogenic keratocyst. Indian J Pathol Microbiol [serial online] 2023 [cited 2023 Jun 1];66:435-7. Available from:

Odontogenic keratocyst (OKC) is a developmental odontogenic cyst affecting the oral and maxillofacial regions. Marsupialization procedure has been proved to effectively treat OKC and reduce the chances of recurrence in selective patients who cooperate to irrigate the cavity regularly.[1]

A 20-year-old female patient presented with a complaint of swelling in the left side of her face for the past 3 months. The swelling was associated with intermittent, dull pain that was relieved upon taking medications. Extra orally, the swelling was tender, measured 2 cm × 3 cm and crackled on palpation. Paresthesia of the left mandible body was observed. Intra orally, the swelling extended from 34 to 37 obliterating the buccal vestibule [Figure 1]. The associated teeth were found to be vital. Orthopantomogram (OPG) revealed a well-defined, unilocular radiolucency extending from 33 to 38 [Figure 2]. Incisional biopsy was suggestive of OKC. Decompression and marsupialization were done 3 months later to relieve the pressure within the cystic cavity. Patient reported 5 months after marsupialization and surgical segmental resection of mandible was done.
Figure 1: (a) Intraoral photograph of the swelling. (b) Intra-operative photograph taken during marsupialization. (c) Intra-operative photograph taken during resection revealing facture of mandible (arrow)

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Figure 2: OPG revealing the extent of the lesion

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Formalin-fixed specimens were routinely processed and stained with hematoxylin and eosin. Microscopic examination revealed parakeratinized stratified squamous cystic lining epithelium in association with inflamed, fibrovascular connective tissue [Figure 3]. In the cystic wall, round, eosinophilic, fibrillary structures were observed surrounded by chronic inflammatory cells and foreign body giant cells. Large round structures with outer, brown shell enclosing polyhedral, eosinophilic cells were seen in the connective tissue, which was validated by a botanist as mustard seed. Pale, eosinophilic structures resembling plant material were also found which exhibited positive birefringence when viewed under polarizing microscope. Special stains like Masson trichrome and periodic acid-Schiff (PAS) reagent were used to confirm the nature of the foreign body present in the cystic wall [Figure 4]. Masson trichrome positively stained hyaline rings for collagen. The plant material also stained positive for PAS. A diagnosis of OKC associated with granuloma induced by vegetal inoculation was given.
Figure 3: (a) Histopathological features suggestive of OKC. (b) Hyaline rings (white arrow) with giant cells present in the inflamed, fibrovascular cystic wall. (c) Plant material exhibiting positive birefringence

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Figure 4: (a) Masson trichrome positive hyaline rings (white arrow). (b) PAS positive plant material. (c) PAS positive mustard seed

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Decompression and marsupialization are done for large OKC to relieve the pressure within the cystic cavity, to prevent damage to vital structures like the tooth, the maxillary sinus, or the inferior alveolar canal and to decrease the lesion size thereby avoiding extensive surgery.[2] It has been observed that the presence of inflammation subsequent to marsupialization procedure changes the biologic behavior to a less aggressive form. Marsupialization exposes the cyst to the oral cavity resulting in histological thickening of the cystic lining epithelium, which is eventually replaced by the oral epithelium and in due course, the lesion completely disappears followed by new bone formation.[3] This procedure may pose a potential risk for the implantation of a foreign body, when not adequately irrigated, as seen in our case.

'Granuloma induced by vegetal inoculation' is the term recently suggested by Kimura TD et al.[4] to describe foreign body granulomatous reaction occurring in response to the implantation of vegetal material. Such granulomas are common in the oral cavity, typically seen in the posterior mandible and occur rarely in the walls of inflammatory odontogenic cysts.[5] The vegetable matter gains access to the cystic walls when there is open communication of cyst to oral cavity through extraction socket or tooth left open for a root canal or grossly decayed tooth. The cellulose moiety present in the plant cell wall is indigestible by the tissue macrophages and is responsible for inducing granuloma.

The histological appearance of granuloma induced by vegetal inoculation varies depending on the evolutionary stage of the vegetal matter. It is characterized by the presence of multinucleated foreign body giant cells, inflammatory cells, and homogeneous, eosinophilic material called hyaline rings surrounded by the fibroblasts. Hyaline material may also be present as ovoid, spiral, horseshoe-shaped, filamentous, or amorphous masses. The chronic exposure to the enzymes secreted by the inflammatory cells results in changes in the structure of hyaline ring which is a rounded structure enclosing amorphous material in the early stage, evolving into a roughly circular, homogeneous, or fibrillary mass.[6] In some cases, where the hyaline ring formation is not evident, it is difficult to recognize these puzzling structures as plant material since they tend to lose their morphologic characteristics. The foreign material present in our study was validated by a botanist as mustard seed. Vegetable parts like pigmented pericarp when fragmented may mimic the cuticle of the maggot and the endocarp may resemble fat cells of larva. Oral myiasis can be excluded from the differential diagnosis with the help of polarizing microscopy, which aids in the confirmation of birefringent cellulose moiety.

Obtaining proper clinical history, recognition of these plant materials in biopsies, and the use of additional diagnostic techniques such as special stains and polarizing microscopy to diagnose their exact nature is essential to avoid any delay in the treatment plan.


We acknowledge Mr. Shiva for the valuable technical support rendered by him.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Speight PM, Takata T. New tumour entities in the 4th ed.ition of the World Health Organization classification of head and neck tumours: Odontogenic and maxillofacial bone tumours. Virchows Archiv 2018;472:331-9.  Back to cited text no. 1
Bland PS, Shiloah J, Rosebush MS. Odontogenic keratocyst: A case report and review of an old lesion with new classification. J Tenn Dent Assoc 2012;92:33.  Back to cited text no. 2
Pogrel MA, Jordan RC. Marsupialization as a definitive treatment for the odontogenic keratocyst. J Oral Maxillofac Surg 2004;62:651-5.  Back to cited text no. 3
Kimura TD, Carneiro MC, Coelho YF, De Sousa SC, Veltrini VC. 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. Oral Dis 2020;27:391-403.  Back to cited text no. 4
Philipsen HP, Reichart PA. Pulse or hyaline ring granuloma. Review of the literature on etiopathogenesis of oral and extraoral lesions. Clin Oral Investig 2010;14:121-8.  Back to cited text no. 5
Henriques ÁC, Pereira JS, Nonaka CF, Freitas RA, Pinto LP, Miguel MC. Analysis of the frequency and nature of hyaline ring granulomas in inflammatory odontogenic cysts. Int Endod J 2013;46:20-9.  Back to cited text no. 6

Correspondence Address:
Bose Divya
Department of Oral Pathology and Microbiology, SRM Dental College, Bharathi Salai, Ramapuram, Chennai - 600 089, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpm.ijpm_40_21

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]


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