|Year : 2016 | Volume
| Issue : 1 | Page : 74-78
Unusual presentation of keratocystic odontogenic tumor: Two case reports
Sunitha Kesidi1, Kotya Naik Maloth1, Vinay Kumar Reddy Kundoor1, Moni Thakur2
1 Department of Oral Medicine and Radiology, Mamata Dental College and Hospital, Khammam, Telangana, India
2 Department of Oral Pathology and Microbiology, Mamata Dental College and Hospital, Khammam, Telangana, India
|Date of Web Publication||8-Sep-2016|
Department of Oral Medicine and Radiology, Mamata Dental College and Hospital, Khammam – 507 002, Telangana
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Keratocystic odontogenic tumor (KOT) is a common odontogenic cyst with aggressive behavior with a high recurrence rate. Features that predict recurrence of KOT are thin friable epithelium which is difficult to enucleate and presence of satellite cysts in the fibrous wall. Most of the lesions grow in an anteroposterior direction without causing any bony expansion. Here, we report two cases of KOT with different clinical presentation.
Keywords: Odontogenic cyst, odontogenic keratocyst, satellite cysts
|How to cite this article:|
Kesidi S, Maloth KN, Kundoor VK, Thakur M. Unusual presentation of keratocystic odontogenic tumor: Two case reports. J Indian Acad Oral Med Radiol 2016;28:74-8
|How to cite this URL:|
Kesidi S, Maloth KN, Kundoor VK, Thakur M. Unusual presentation of keratocystic odontogenic tumor: Two case reports. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2020 Mar 29];28:74-8. Available from: http://www.jiaomr.in/text.asp?2016/28/1/74/189981
| Introduction|| |
Odontogenic keratocyst (OKC) is a developmental cystic lesion of odontogenic origin and is derived from dental lamina. It was first described by Philipsen in 1956, and it was renamed by Philipsen in 2005 as keratocystic odontogenic tumor (KOT), which was accepted by the World Health Organization (WHO), as it is known for its aggressive nature due to its rapid growth and invasion into adjacent structures including bone. It is defined as “a benign uni or multicystic, intraosseous tumour of odontogenic origin, with a characteristic lining of parakeratinized stratified squamous epithelium and potential for aggressive, infiltrative behavior,”, The incidence of KOT accounts for approximately 3–11% of all odontogenic cysts and the prevalence varies from 11.6 to 19.1%. The clinical behavior of KOT tends to grow in an anteroposterior direction within the medullary cavity of the bone without causing any obvious bony expansion.,
| Case Reports|| |
A 41-year-old male patient reported to the department with a chief complaint of pain in his lower left back tooth region since 1 year and swelling on his left side of the face since 10 days, which was initially smaller in size and gradually progressed to the present size. His past medical and dental history was noncontributory. On extraoral examination [Figure 1] and [Figure 2], a solitary well-defined oval-shaped swelling with a shiny and stretched surface was noticed on the left side of the face, measuring approximately 4.5 × 4 cm in size with a restricted mouth opening (12 mm) [Figure 3]. On palpation, it was tender, soft in consistency, and compressible with palpable solitary left submandibular lymph node, which was mobile and tender. On intraoral examination, periodontal pocket with pus discharge in relation to 37, 38 region was noted. Based on the history and clinical examination, a provisional diagnosis of space infection secondary to periodontal abscess in relation to 37, 38 were made.
Hemogram was within normal limits. On fine needle aspiration, pus was obtained. Radiographic examination such as mandibular lateral occlusal radiograph did not show any cortical expansion [Figure 4]. Orthopantomograph revealed single, well-defined radiolucency extending anteroposteriorly from the mesial aspect of 44 to 0.5 cm below the left sigmoid notch [Figure 5]. Based on the history, clinical, and radiographic examination, a provisional diagnosis of OKC was made with a differential diagnosis of ameloblastoma, central giant cell granuloma (CGCG), and odontogenic myxoma. Further investigation such as incisional biopsy revealed [Figure 6] cystic cavity lined by corrugated parakeratinized squamous epithelium with 4–5 layers of thickness along with pallisaded hyperchromatic nuclei in the basal layer. The underlying connective tissue showed inflammatory cells such as lymphocytes and plasma cells, suggestive of inflamed KOT.
|Figure 4: Case 1- Mandibular occlusal radiograph with no cortical expansion|
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|Figure 5: Case 1- Orthopantomograph showing well-defined radiolucency involving the left side of mandible|
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|Figure 6: Case 1- Photomicrograph showing corrugated parakeratinized squamous epithelium with underlying inflammatory cells|
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A 37-year-old male patient reported to the department with a chief complaint of swelling in the lower right back teeth region since 1 month associated with pain since 10 days.
Patient was apparently normal 1 month back, and then noticed a swelling, which was initially smaller in size and gradually increased to the present size associated with intermittent pain. Past dental history revealed extraction of teeth 15 years back due to mobility. Medical history was noncontributory. On extraoral examination [Figure 7], a solitary, diffuse, dome-shaped swelling with stretched surface was noticed on the right side of the face, measuring approximately 2 × 2 cm in size. On palpation, it was normothermic, tender, soft in consistency, and compressible with palpable solitary right submandibular lymph node which was mobile and nontender. On intraoral examination [Figure 8], mild swelling in relation to 44, 45, 46 region with obliteration of buccal vestibule was seen, which was firm in consistency, tender, and noncompressible. Partially erupted mobile teeth in relation to 48 was noted. Based on the history and clinical examination, a provisional diagnosis of pericoronal abscess in relation to 48 was considered.
|Figure 8: Case 2- Intraoral picture showing mild buccal vestibular obliteration on right side|
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Routine hematological investigations and fine needle aspiration was noncontributory. Mandibular occlusal radiograph revealed buccal and lingual cortical expansion on the right side [Figure 9]. Orthopantomograph revealed well-defined multilocular radiolucency extending from the right sigmoid notch to the left sigmoid notch of the mandible, with loss of continuity of lower border of the mandible on right posterior region and thinning of lower left posterior border of the mandible [Figure 10]. Based on the history, clinical, and radiographic examination, a provisional diagnosis of ameloblastoma of the mandible was given with a differential diagnosis of OKC, CGCG, and odontogenic myxoma. Incisional biopsy revealed [Figure 11] corrugated parakeratinized squamous epithelium with 8–10 layers of uniform thickness. The basal cell layer showed low columnar cells with hyperchromatic nuclei and polarization of cells, suggestive of KOT.
|Figure 9: Case 2- Mandibular occlusal radiograph with buccal and lingual cortical expansion on the right side|
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|Figure 10: Case 2- Orthopantomograph showing well defined multilocular radiolucency involving the entire mandible|
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|Figure 11: Case 2- Photomicrograph showing corrugated parakeratinized squamous epithelium with hyperchromatic nuclei and polarization of cells|
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| Discussion|| |
OKC is the one of the common developmental cystic lesions arising from the odontogenic epithelium such as the remnants of dental lamina in the mandible and maxilla. In 1876, Mikulicz was the first person to describe it as a part of a familial condition affecting the jaws, and in 1926 it was named as “Cholesteatoma,” Later Philipsen, in 1956, named it as OKC; the aggressive nature of OKC was described by Pindborg and Hansen for the first time. Based on the clinical behavior of OKC, Toller  in 1967 considered it as a benign neoplasm; later, in 1984 Ahlfors and others classified it as true benign cystic epithelial neoplasm. In 2003, Shear renamed it as keratocystoma and it was later modified by Philipsen in 2005 as KOT. The change in terminology from OKC to KOT was substantiated as studies on nevoid basal cell carcinoma syndrome and sporadic KOT have shown molecular evidence of two-hit mechanism as in the pathogenesis of tumors demonstrating loss of alleles at two or more loci of 9q22 chromosome, leading to overexpression of bcl-1 and p53. This concept supports KOT as a tumor rather than a cyst.
KOT most commonly occurs in the mandible (65%) than the maxilla, with a predilection at the angle and ramus region (73.2%). 40–60% of the KOT occurs in the second and third decade, with an average patient age of 30.8 years, with a male predilection. In the cases reported here, site and gender were consistent with the literature, except the age of the patients, which was above the average age of occurrence. Most of the early lesions remain asymptomatic and do not reveal any gross clinical signs and symptoms, as they tend to extent in the medullary cavity in anteroposterior direction and are found incidentally during routine radiographic examination., The lesion can grow considerably large in size when it involves the maxillary sinus, entire ramus involving condylar head, and coronoid processes, with clinically observable expansion in later stages, as in the present cases.
The common signs and symptoms of KOT are pain, swelling, and discharge, and occasionally expansion with bony perforation, paraesthesia, and pathological fracture. The present cases were associated with all the common signs and symptoms of KOT including expansion with bony perforation; none of the cases presented with paraesthesia and pathological fracture except trismus, which was seen in Case 1.
Radiographically, KOT presents as a well-defined radiolucency with unilocular (73.7%) or multilocular (26.6%) appearance. The unilocular variant present as smooth well-defined margins whereas multilocular variant presents with scalloped borders. The present cases represent unilocular (Case 1) and multilocular (Case 2) radiolucency with scalloped borders. KOT approximating the tooth causes displacement (28.3%) and/or root resorption (5%), which were not evident in the present cases.
Histopathologically, KOT has certain gold standard diagnostic features, which were reported by Pindborg and Hansen, for guiding pathologists and clinicians, as follows: (a) The epithelial lining is very thin and uniform in thickness, friable, and often difficult to procure at the time of biopsy with little evidence of rete ridges, (b) The basal squamous epithelial layer is prominent and palisaded with the thin spinous layer and intracellular edema, (c) Keratinization is predominantly parakeratotic with nuclei but may be orthokeratotic layer and is corrugated, (d) The fibrous connective tissue wall is generally thin and inflammation is absent, and (e) There is a tendency of the epithelium to separate from the connective tissue lining and sometimes “abtrofung” or dropping down phenomenon of epithelial elements in the connective tissue wall is also seen. The abovementioned features closely resemble low grade squamous cell carcinoma, which justifies the malignant transformation of KOT into intraosseous carcinoma at a of rate 0.1–1.8% according to the literature.
The management of KOT depends on the clinical presentation and extent of the lesion, considering these, conservative or aggressive treatment modalities exist. Conservative treatment includes enucleation with/without curettage, or marsupialization, whereas aggressive treatment includes peripheral osteotomy, osseous resection with or without continuity defect, and curettage with chemical application of carnoy's solution, cryotherapy, or electrocautery and resection., The goal is to choose the treatment modality that carries the lowest risk of recurrences because the recurrence rate of KOT varies from 2.5 to 62%, which is high when compared to other cysts of jaw. According to Brannon in 1976, the high recurrence rate of KOT is due to incomplete removal of the cyst lining and development of new KOT from satellite cysts.
| Conclusion|| |
KOT, though being a common lesion, has varied clinical presentation with aggressive behavior and is setting a diagnostic challenge for clinicians, as reported in this review. Although diagnosis can be confirmed by routine radiography and histopathology, it is worthwhile shifting to higher diagnostic modalities such as computed tomography and magnetic resonance imaging to examine the extent of the lesion. This helps in proper surgical management and prevents recurrence.
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.
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Conflicts of interest
There are no conflicts of interest.
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