Clinics and Practice 2020; volume 10:1255

Keratinocyte dissociation gical excision.1 Based on the clinico-patho- (desmolysis/acantholysis) logical features, there are four main sub- Correspondence: Sachin C. Sarode, types of ; conventional, uni- Department of Oral Pathology and in ameloblastoma cystic, extraosseous or peripheral and Microbiology, Dr. D.Y. Patil Dental College metastasizing ameloblastoma.2 It is the only and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant- 1 1 that displays diversified Tukaram Nagar, Pimpri, Pune 411018, India. Sachin C. Sarode, Gargi S. Sarode, E-mail: [email protected] Praveen Birur,2 Yaser A. Alhazmi,3 histomorphological features and hence, has Shankargouda Patil3 many histopathological subtypes like follic- Key words: Ameloblastoma; odontogenic 1 ular, plexiform, acanthomatous, granular tumor; jaw tumor; desmolysis; acantholysis. Department of Oral Pathology and cell, clear cell, desmoplastic etc.3 Microbiology, Dr. D.Y. Patil Dental Combination of the above histopathological Conflict of interest: the authors declare no College and Hospital, Dr. D.Y. Patil features could be present in the form of potential conflict of interests. Vidyapeeth, Sant-Tukaram Nagar, hybrid ameloblastoma.4 Some rare variants Pimpri, Pune, MH, India; 2Department reported in the literature are hema- Received for publication: 18 April 2020. 5 Revision received: 26 April 2020. of Oral Medicine and Radiology, KLE’s gioameloblastoma and papilliferous kera- Accepted for publication: 18 May 2020. Institute of Dental Sciences, Bangalore, toameloblastoma.6 For most of the India; 3Department of Maxillofacial histopathological subtypes of ameloblas- This work is licensed under a Creative Surgery and Diagnostic Sciences, toma, clinical and radiological features are Commons Attribution NonCommercial 4.0 Division of Oral Pathology, College of usually similar in nature, which includes License (CC BY-NC 4.0). mandibular posterior location, painless Dentistry, Jazan University, Jazan, expansion of cortical plates and multi-locu- ©Copyright: the Author(s), 2020 Saudi Arabia lar radiographic appearance.1 However, Licensee PAGEPress, Italy Clinics and Practice 2020; 10:1255 desmoplastic ameloblastoma is an excep- doi:10.4081/cp.2020.1255 tion to this finding as it most commonly occurs in the maxillary anterior region and Abstract shows mixed radio-opaque and radio-lucent only 7 Ameloblastoma is the only odontogenic appearance. imen revealed large ameloblastomatous fol- tumor that displays diversified histomor- In the present paper we reported an licular spaces with peripheral extremely unusual presentation of phological features with subtypes like fol- columnar/cuboidal cells and central stellate ameloblastoma, which is characterizeduse by licular, plexiform, acanthomatous, granular reticulum like cells. At few places central desmolysis or acantholysis of central stel- cell, clear cell, desmoplastic etc. In this stellate reticulum like cell displayed late reticulum like cells. paper we presented an extremely unusual squamoid morphology suggesting acan- presentation of ameloblastoma, which is thomatous change. In most of the areas, characterized by desmolysis or acantholysis central cells were separated from each other due to keratinocyte dissociation leading to of stellate reticulum-like cells caused due to Case Report keratinocyte dissociation. A 35-year-old desmolysis/acantholysis (Figure 2A and C). male patient presented with a painless hard A 35-year-old male patient visited to the Desmolytic cells were seen as an isolated 3×3 cm swelling in the mandibular right outpatient department with chief complaint entity in the follicular space with round to posterior region in the past 4-5 months. of painless hard swelling in the mandibular polygonal shaped morphology (Figure 2B Radiographic examination revealed a multi- right posterior region since 4-5 months. and D). The ameloblastic follicles were also locular radiolucent lesion in the body of There was no history of trauma or any dis- characterized by numerous clear spaces mandible with resorption of the roots. charge from the lesion. The medical and caused due to acantholysis. This appearance Histopathological examination revealed dental history was unremarkable. The was seen throughout the section. ameloblastic follicles with central cells swelling was gradually increasing in size to Intriguingly, we also observed dense bundle showing keratinocyte dissociation leading reach the present size of 3×3 cm. of collagen fibers with hyalinization in the to desmolysis/acantholysis. Non-commercial Desmolytic Radiographic examination revealed a multi- stroma tissue (Figure 2D). However, cells were seen as an isolated entity in the locular radiolucent lesion extending from absence of kite or animal like configura- follicular space with round to polygonal distal surface of right mandibular first tions of the ameloblastomatous epithelium shaped morphology. Future retrospective molar to retro-molar region (Figure 1). ruled out the possibility of desmoplastic studies on archival samples of ameloblas- Radiolucency extended up to the lower bor- ameloblastoma.7 The final diagnosis of fol- toma are recommended to relook into iden- der of the mandible. Each locules were licular ameloblastoma (desmolytic or acan- tification of such rare phenomenon. This well-demarked with the radio-opaque sep- tholytic variant) was made and patient was will help in better understanding of the inci- tas. Root resorptions were present in the posted for the surgical excision but we lost dence rate and biological behavior of this first, second and third molar. Based on the the follow up with the patient. rare variant of ameloblastoma. clinico-pathological observations a diagno- sis of ameloblastoma and differential diag- nosis of odontogenic and central giant cell granuloma was made. Aspiration Discussion and Conclusions Introduction of the lesion does not yield any material thus ruling out cystic and vascular lesions. Ameloblastoma is known for the histo- Ameloblastoma is one of the most com- Intra-oral incisional biopsy was performed morphological diversity that leads to vari- mon benign odontogenic of by creating small window on buccal aspect ous histopathological subtypes.2 These sub- epithelial origin. It is considered as locally of the body of the mandible. types mainly show metaplastic changes in aggressive and often managed with the sur- Histopathological examination of spec- the morphological pattern of central cells

[Clinics and Practice 2020; 10:1255] [page 31] Case Report leading to acanthomatous (squamous meta- ysis of the skin or oral epithelium is rarely with attachment of basal cell layer to the plasia), granular cell, clear cell, basal cell, seen histopathological phenomenon. underlying basement membrane. Histo - etc.8 Sometimes the stromal changes can Tissues fixed in a diluted formalin concen- pathologically, this artifact looks exactly also produce different subtype of tration, saline or water produced prominent similar to the and Darier’s dis- , which includes desmo- acantholysis of the superficial epithelium ease.13 In the present case, possibility of fix- plastic and hemangioameloblastoma.4,5 In the present case, keratinocyte dissociation (desmolysis or acantholysis) was present in the central stellate reticulum like cells, which is first of its kind presentation in the literature. Distinction of ameloblastoma into a particular histopathological type is of para- mount importance as it determines the aggressive behavior as well as guides the management.9 In this regard, desmoplastic ameloblastoma and granular cell ameloblas- toma were considered as the most aggres- sive subtypes due to their high rate of recur- rence.10,11 In the present case, we reported an extensive desmolysis or acatholysis of the central stellate shaped cells of ameloblastic follicles and hence labeled this entity as a desmolytic/acantholytic amelo - Figure 1. Panoramic radiograph showing multi-locular lesion in the mandibular posteri- blastoma. As it is first of its kind reported in or region. only the literature, it is very difficult to comment on the biological behavior of this unique subtype of ameloblastoma. Hence, future prospective studies are recommended to better understand the biological behavior. use The present case was present at the mandibular posterior region with painless swelling and expansion of the cortical plates. Radiographic examination revealed multi-locular lesion with resorption of the mandibular molar roots. All these features are very characteristics of ameloblastoma except desmoplastic ameloblastoma, which mainly occurs at maxillary anterior region with mixed radiolucent and radiopaque appearance.11 Based on the present case, which is first of its kind, it will be prema- ture to comment on the uniqueness of the clinical and radiological feature. It is very difficult to comment on the exact reason for such unique histomorpho-Non-commercial logical appearance. Acantholysis and desmolysis of epithelial cells is the charac- teristic features seen in the pemphigus and pemphigus-like lesions where the destruc- tion of desmosomal junction takes place due to formation of auto-antibodies against the desmoglein 1 and 3, which are the cell adhesion molecules found in desmosomes.12 Since ameloblastic follicles are epithelial in origin and also possesses desmosomal junc- tions, the possibility of breakdown of desmosomal junctions in a stellate reticu- lum like cells by similar or any other Figure 2. Photomicrograph showing microscopic features of acatholytic/desmolytic unknown mechanism cannot be underesti- ameloblastoma. Scanner view (40×) shows ameloblastomatous proliferation of odonto- mated. Hence, future studies are warranted genic epithelium with numerous clear spaces (A and C). High power magnification in this direction to authenticate the pro- (400×) displays numerous acatholytic cells (black arrow) and clear spaces (white arrow) in the ameloblastic follicle and desmoplasia (red arrow) in the stroma (B and D). posed hypothesis. (Hematoxylin and eosin stain). Artifact related desmolysis or acanthol-

[page 32] [Clinics and Practice 2020; 10:1255] Case Report ation artifact in acantholytic or desmolytic logical behavior of this rare variant of 6. Altini M, Slabbert HD, Johnston T. appearance of central cell of the follicle is ameloblastoma. Papilliferous keratoameloblastoma. J quite possible. But, biopsy specimen was Oral Pathol Med 1991;20:46-8. received and fixed in 10% neutral buffered 7. Sun ZJ, Wu YR, Cheng N, et al. formalin and hence it rules out possibility of Desmoplastic ameloblastoma - A fixation artifact. Moreover, other stromal References review. Oral Oncol 2009;45:752-9. tissue elements such as fibroblasts, collagen 8. Effiom OA, Ogundana OM, Akinshipo bundles, blood vessels, etc. were devoid of 1. Reichart PA, Philipsen HP, Sciubba JJ. AO, Akintoye SO. Ameloblastoma: cur- any artifact related changes. The new classification of Head and rent etiopathological concepts and man- Histopathological diagnosis of Neck Tumours (WHO)--any changes?. ameloblastoma is very straightforward due Oral Oncol 2006;42:757-8. agement. Oral Dis 2018;24:307-16. to its typical and pathognomonic features. 2. Wright JM, Vered M. Update from the 9. McClary AC, West RB, McClary AC, et Hence, there could be a possibility of over- 4th edition of the World Health al. Ameloblastoma: a clinical review looking this unique finding during routine Organization classification of head and and trends in management. Eur Arch diagnosis of ameloblastoma by the patholo- neck tumours: odontogenic and max- Otorhinolaryngol 2016;273:1649-61. gists. This could be one of the reasons why illofacial bone tumors. Head Neck 10. Pinheiro JJ, Freitas VM, Moretti AI, et it was not reported previously. Hence, retro- Pathol 2017;11:68-77. al. Local invasiveness of ameloblas- spective studies on the archival samples are 3. Effiom OA, Ogundana OM, Akinshipo toma. Role played by matrix metallo- warranted to understand the incidence, AO, Akintoye SO. Ameloblastoma: cur- proteinases and proliferative activity. rent etiopathological concepts and man- demographics and clinico-pathological fea- Histopathology 2004;45:65-72. agement. Oral Dis 2018;24:307-16. tures of this rare phenomenon. This will 11. Anand R, Sarode GS, Sarode SC, et al. 4. Philipsen HP, Reichart PA, Takata T. help in labeling this unique phenomenon as Clinicopathological characteristics of distinguished histopathological subtype of Desmoplastic ameloblastoma (includ- desmoplastic ameloblastoma: A system- ameloblastoma. ing "hybrid" lesion of ameloblastoma). atic review. J Investig Clin Dent 2018;9: In conclusion, we reported a very Biological profile based on 100 cases only unique histopathological presentation of from the literature and own files. Oral 10.1111/jicd.12282. follicular ameloblastoma in the form of Oncol 2001;37:455-60. 12. Kasperkiewicz M, Ellebrecht CT, desmolysis/acantholysis. Future retrospec- 5. Sarode GS, Sarode SC, Vaidya K. Takahashi H, et al. Pemphigus. Nat Rev tive studies on archival samples are recom- Intraluminal plexiform use heman- Dis Primers 2017;3:17026. mended to identify such presentation in gioameloblastomatous proliferation in 13. Chatterjee S. Artefacts in histopatholo- ameloblastoma. This will help in better unicystic ameloblastoma: an unusual case gy. J Oral Maxillofac Pathol 2014;18: understanding of the true incidence and bio- report. Indian J Dent Res 2013;24: 390-2. S111-6.

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