Document Detail

Peripheral ameloblastoma of the upper gingiva: Report of a case and literature review.
Jump to Full Text
MedLine Citation:
PMID:  24790720     Owner:  NLM     Status:  PubMed-not-MEDLINE    
According to the 2005 histological classification of odontogenic neoplasms by the World Health Organization, ameloblastoma is a benign, locally invasive epithelial odontogenic tumor of putative enamel organ origin. There are four distinct subgroups in which this neoplasm can be gathered: the solid/multicystic type, the unicystic type, the desmoplastic and the peripheral type. Peripheral ameloblastoma is believed to be the rarest subgroup, making up for 2 to 10% of all ameloblastomas. From its first description by Kuru in 1911 to date, less than 200 cases of PA have been described in literature. PAs commonly affect the mandible, in the maxilla the most common location is the soft palatal tissue of the tuberosity area. The present report discusses a rare case of PA aroused in the gingiva of upper jaw in a 64-year-old woman. The treatment of the lesion and its immunohistochemical phenotype are described. A review of the literature is also performed, focusing on the epidemiological and pathological aspects of the lesions and their implications on the therapy. Key words:Peripheral ameloblastoma, upper gingiva, ameloblastoma.
Dario Bertossi; Vittorio Favero; Massimo Albanese; Daniele De-Santis; Manuela Martano; Antongiulio Padovano-di-Leva; Iride De-Florio; Pier F Nocini; Lorenzo Lo-Muzio
Publication Detail:
Type:  Journal Article     Date:  2014-04-01
Journal Detail:
Title:  Journal of clinical and experimental dentistry     Volume:  6     ISSN:  1989-5488     ISO Abbreviation:  J Clin Exp Dent     Publication Date:  2014 Apr 
Date Detail:
Created Date:  2014-05-05     Completed Date:  2014-05-05     Revised Date:  2014-05-07    
Medline Journal Info:
Nlm Unique ID:  101603132     Medline TA:  J Clin Exp Dent     Country:  Spain    
Other Details:
Languages:  eng     Pagination:  e180-4     Citation Subset:  -    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Full Text
Journal Information
Journal ID (nlm-ta): J Clin Exp Dent
Journal ID (iso-abbrev): J Clin Exp Dent
Journal ID (publisher-id): Medicina Oral S.L.
ISSN: 1989-5488
Publisher: Medicina Oral S.L.
Article Information
Download PDF
Copyright: © 2014 Medicina Oral S.L.
Accepted Day: 14 Month: 12 Year: 2013
Received Day: 7 Month: 4 Year: 2013
Electronic publication date: Day: 1 Month: 4 Year: 2014
collection publication date: Month: 4 Year: 2014
Volume: 6 Issue: 2
First Page: e180 Last Page: e184
PubMed Id: 24790720
ID: 4002350
Publisher Id: 51124
DOI: 10.4317/jced.51124

Peripheral ameloblastoma of the upper gingiva: Report of a case and literature review
Dario Bertossi1
Vittorio Favero1
Massimo Albanese1
Daniele De-Santis1
Manuela Martano2
Antongiulio Padovano-di-Leva3
Iride De-Florio4
Pier F. Nocini1
Lorenzo Lo-Muzio3
1Unit of Dentistry and Maxillo-Facial Surgery, University of Verona, Italy
2Department of Veterinary Medicine and Animal Productions, University of Naples, Italy
3Department of Clinical and Experimental Medicine, University of Foggia, Italy
4Department of Medicina clinica, sanita pubblica, scienze della vita e dell`ambiente, University of L`Aquila, L`Aquila, Italy
Correspondence: Via Rovelli, 48 71122, Foggia, Italy , E-mail:
[conflict] Conflict of interest statement: The authors have declared that no conflict of interest exist.


According to the 2005 histological classification of odontogenic neoplasms by the World Health Organization (WHO) (1-3), ameloblastoma is a benign, locally invasive epithelial odontogenic tumor of putative enamel organ origin. Account for about one percent of all oral tumors and about 11% of odontogenic tumors (4). There are four distinct subgroups in which this neoplasm can be gathered: the solid/multicystic type, the unicystic type, the desmoplastic and the peripheral type (1). Peripheral ameloblastoma (PA) is believed to be the rarest subgroup, making up for 2 to 10% of all ameloblastomas (2,5). It was first described by Kuru in 1911 (6). To date, less than 200 cases of PA have been described in literature (7,8). PAs commonly affect the mandible (3,9-12), especially the lingual gingiva in the premolar region (2,13), followed by the anterior region (2,3). In the maxilla, the most common location is the soft palatal tissue of the tuberosity area (2,5). The present report discusses a rare case of PA aroused in the gingiva of upper jaw.

Case Report

A 64-year-old Caucasian woman referred to our Unit with a 2-month history of a tender lesion on the vestibular gingiva of the posterior left maxillary region. No pain or bleeding associated to the lesion was reported. The patient reported previous history of surgically treated breast cancer. She affirmed a smoking history of 5 cigarettes per day in the last 40 years and occasional alcohol consumption. At the clinical examination, there was a sessile mass of about 1 cm distally to the second molar. The mass was dark red and ulcerated (Fig. 1). The consistence was tender; there were no bleeding or pain on palpation. No other lesions in the oral cavity and in the oropharynx, or abnormalities in the head and neck district were reported. CT scan, MRI scan and an incisional biopsy were subsequently performed. Imaging described a 19mm x 15mm x 22 mm mass arising from the posterior alveolar edge of the left maxillary bone, protruding into the vestibule with no signs of bone erosion, or muscular infiltration with regard to the internal and external left pterygoid muscles. No lymphadenopathies were described. The incisional biopsy assessed the presence of a plexiform structured epithelial neoplasm, with basaloid and squamous components; immunohistochemistry showed strong positivity for anticytokeratin antibodies MNF-116, a mild positivity for podoplanin and negativity for calretinin. The overall pattern was suggestive for peripheral ameloblastoma. The patient subsequently underwent the resection of the lesion with surrounding bone tissue and the extraction of the second molar using an intraoral access; a Bichat flap was used for closure. The final pathologic diagnosis was peripheral ameloblastoma, with a plexiform pattern consisting of islands and strands of odontogenic epithelium within a fibrous stroma (Fig. 1). The tumor resulted to be strongly positive for CK14 (Fig. 1) and diffusely positive for CK19 (Fig. 1) and CKAE1-3 (Fig. 1). Ki-67 labeling index was 2%. Moreover, expression of podoplanin was evident in peripheral cuboidal neoplastic cells of tumor nests, whereas it was expressed slightly in central stellate reticulum-like cells (Fig. 1). No complications were observed during recovery. The patient was dismissed three days after surgery. No recurrence of disease was observed after 2-year follow-up.


Epidemiological data extrapolated from the literature assess the maximum incidence of PA in the sixth decade of life, with a male/female ratio amounting to 1,9:1, with an average age of presentation of 52,9 years in males and 50,6 years in females (10). PA seems to be more male-predominant and to occur at a higher age than its intraosseous counterpart (M/F 1,14:1; 35 years) (14,15). The most frequent onset site is the mandibular premolar region, followed by the anterior mandibular region and by the tuber maxillae. Roughly 7 cases of PA out of 10 occur in the lower jaw (2). Review of the English language literature between 1987 to 1999, disclosed only 13 in the maxillary area (12). In their review of 160 PA cases published in English or in Japanese language (74 cases) Philipsen et al. reported 46 cases (29.1%) in the maxilla and only 23 cases (8 in not-japanese patients) involving the upper gingiva (2). However other few cases were reported in literatura ( Table 1).

The actual histogenesis of PA is still controversial. Two main theories about the cellular origin of PA have been developed. Some tumors, being located completely within the gingival connective tissue with no contact to the surface epithelium or divided from the surface epithelium by a connectival band, are suggestive to derive from the “Serre`s pearls”, that is to say from the extraosseous cellular residuals of the dental lamina (2,3,8). On the other hand, many other cases of PA present themselves in a very close relationship with the surface epithelium. Ide et al. described a case of PA in which multiple sectioning failed to detect any epithelial nests in the submucosa, in fact describing an in-situ lesion that seems to provide a remarkable evidence that at least a share of cases of PA take origin from the surface epithelial layer (16,17). Multifocal growth of PA has also been described (18).

The macroscopic presentation of PA is usually that of a solid mass, either sessile or pedunculated, which may be in color from pink to dark red (8). The surface of the mass may be smooth, granular or warty (8). Minute cystic spaces filled with fluid may be found when the mass is cut. Dimensions rarely exceed 2 cm in diameter (8). The microscopic aspect of PA is characterized by ameloblastic growth within a squamous epithelial layer, being the tumor composed by nests of loosely connected cells (19). Another interesting issue about the histology of PA lies in its similarity with basal cell carcinoma (BCC). Some Authors tend to consider the two lesions as the same entity, arguing that they share some peculiar aspects such as the proliferation of basal cells and its island-like arrangement with an important presence of fibrous stroma (20). However, if immunohistochemical analysis is considered, the patterns of positivity for cytokeratins is different between PA and BCC, rather suggesting a greater similarity between PA and its intraosseous counterpart and thus an origin of the lesion from odontogenic epithelial remnants and not from the basal cell layer of the gingival epithelium (3). PA is positive for cytokeratin 19, whereas the opposite is true for BCC (8). A correct distinction among PA and BCC is of pivotal importance, since the treatment of the two lesions greatly differs in the required radicality. The debate on the histogenesis, as assessed previously, is still open and challenging (19,21,22). In literature there are four reported cases of a Peripheral desmoplastic ameloblastoma (23-25).

Apart from BCC, differential diagnosis for PA must consider a range of mucosal and submucosal lesions that may occur in the oral cavity, such as pyogenic granuloma, peripheral ossifying fibroma, peripheral giant cell granuloma, odontogenic gingival epithelial hamartoma. Reactions to ill-fitting dentures and post-inflammatory lesions like fissuratum epulis and inflammatory papillary hyperplasia also have to be considered. PA showing continuity with surface epithelium should as well be differentiated from epithelial neoplasms such as squamous cell carcinoma or verrucous carcinoma (26,27).

As far as imaging is concerned, in most cases there is no evidence of bony infiltration. A cortical bone erosion or a local depression, described as cupping or saucerization, may occasionally be described (2,3,5,10,28). The lack of infiltration may be explained through the existence of a fibrous barrier surrounding the lesion generated by the gingiva and the periosteum. This aspect of the biological behavior of PA makes this pathology greatly different from intraosseous ameloblastoma, which conversely is characterized by a high degree of bony erosion and marrow infiltration, with great implications onto the treatment plan (15).

The treatment of choice for PA is the surgical excision with proper disease-free margins (9,29). No extensive radical treatment is usually required. Although the role of radiation therapy in the treatment of ameloblastomas has been investigated (30), the low occurrence and the peculiar non-aggressive behavior of PA seem to discourage this treatment option. The biological evolutional behavior of PA is characterized by a frequent tendency to recurrence [16%-20%], however inferior to the recurrence rate of intraosseous ameloblastoma (2). It is not clear whether the recurrence rate is an actual feature of the lesion or is rather to be due to incomplete removal of the primary mass. Literature describes a few cases of PA with malignant characteristics (31). These cases presented either with primary and metastatic differentiated benign-appearing lesions or with dedifferentiated lesions. Long-term follow-up is therefore mandatory (32).

In conclusion, considering the descriptions of PAs now available in the literature, these lesions seem to be relatively benign pathologies that however should not be considered harmless at all. Some aspects of PA such as, for instance, its histogenesis and its relationships with similar lesions, still require more studies in order to be fully understood.

1. Gardner DG,Heikinheimo K,Shear M,Philipsen HP,Coleman H. World health organization classification of tumors Pathology and genetics of head and neck tumors Year: 2005LyonIARC Press296300
2. Philipsen HP,Reichart PA,Nikai H,Takata T,Kudo Y. Peripheral ameloblastoma: biological profile based on 160 cases from the literatureOral OncolYear: 200137172711120479
3. Kishino M,Murakami S,Yuki M,Iida S,Ogawa Y,Kogo M. A immunohistochemical study of the peripheral ameloblastomaOral DisYear: 2007135758017944675
4. Ghom AG. Textbook of oral medicine: Jaypee Brothers Medical Publishers Year: 2010IndiaLtd276280
5. Nonaka CF,de Oliveira PT,de Medeiros AM,de Souza LB,Freitas Rde A. Peripheral ameloblastoma in the maxillary gingiva: a case reportN Y State Dent JYear: 201379374023513548
6. Kuru H. Ueber das adamantinomaZentralbl Allg PatholYear: 191122291
7. Yamanishi T,Ando S,Aikawa T,Kishino M,Nakano Y,Sasai K. A case of extragingival peripheral ameloblastoma in the buccal mucosaJ Oral Pathol MedYear: 200736184617305641
8. Vanoven BJ,Parker NP,Petruzzelli GJ. Peripheral ameloblastoma of the maxilla: a case report and literature reviewAm J OtolaryngolYear: 2008293576018722894
9. Pogrel MA,Montes DM. Is there a role for enucleation in the management of ameloblastoma?Int J Oral Maxillofac SurgYear: 2009388071219297131
10. Buchner A,Merrell PW,Carpenter WM. Relative frequency of peripheral odontogenic tumors: a study of 45 new cases and comparison with studies from the literatureJ Oral Pathol MedYear: 2006353859116827840
11. Reichart PA,Philipsen HP,Sonner S. Ameloblastoma: biological profile of 3677 casesEur J Cancer B Oral OncolYear: 199531B86997633291
12. Manor Y,Mardinger O,Katz J,Taicher S,Hirshberg A. Peripheral odontogenic tumours--differential diagnosis in gingival lesionsInt J Oral Maxillofac SurgYear: 2004332687315287310
13. el-Mofty SK,Gerard NO,Farish SE,Rodu B. Peripheral ameloblastoma: a clinical and histologic study of 11 casesJ Oral Maxillofac SurgYear: 19914997041886025
14. Reichart PA,Jundt G. Benign epithelial odontogenic tumorsPathologeYear: 200829175618389236
15. Mendenhall WM,Werning JW,Fernandes R,Malyapa RS,Mendenhall NP. AmeloblastomaAm J Clin OncolYear: 200730645818091060
16. Ide F,Mishima K,Miyazaki Y,Saito I,Kusama K. Peripheral ameloblastoma in-situ: an evidential fact of surface epithelium originOral Surg Oral Med Oral Pathol Oral Radiol EndodYear: 2009108763719748296
17. Ide F. Peripheral ameloblastoma of the buccal mucosaOral Surg Oral Med Oral Pathol Oral Radiol EndodYear: 2010109653420416529
18. Gardner DG. Peripheral ameloblastoma: a study of 21 cases, including 5 reported as basal cell carcinoma of the gingivaCancerYear: 197739162533856447
19. Tsuneki M,Maruyama S,Yamazaki M,Cheng J,Saku T. Podoplanin expression profiles characteristic of odontogenic tumor-specific tissue architecturesPathol Res PractYear: 2012208140622326634
20. Simpson HE. Basal-cell carcinoma and peripheral ameloblastomaOral Surg Oral Med Oral PatholYear: 197438233404528440
21. Thosaporn W,Iamaroon A,Pongsiriwet S,Ng KH. A comparative study of epithelial cell proliferation between the odontogenic keratocyst, orthokeratinized odontogenic cyst, dentigerous cyst, and ameloblastomaOral DisYear: 20041022614996290
22. Gonzalez-Alva P,Tanaka A,Oku Y,Miyazaki Y,Okamoto E,Fujinami M. Enhanced expression of podoplanin in ameloblastomasJ Oral Pathol MedYear: 201039103919691459
23. Bologna-Molina R,Mosqueda-Taylor A,de Almeida-Oslei P,Toral-Rizo V,Martinez-Mata G. Peripheral desmoplastic ameloblastoma: histopathological and immunohistochemical profile of a caseMed Oral Patol Oral Cir BucalYear: 201015e846920526273
24. Curran AE,Byerly PD. Peripheral desmoplastic ameloblastoma: report of a rare caseJ Oral Maxillofac SurgYear: 200866820518355614
25. Smullin SE,Faquin W,Susarla SM,Kaban LB. Peripheral desmoplastic ameloblastoma: report of a case and literature reviewOral Surg Oral Med Oral Pathol Oral Radiol EndodYear: 2008105374017764981
26. Lopez-Jornet P,Bermejo-Fenoll A. Peripheral ameloblastoma of the gingiva: the importance of diagnosisJ Clin PeriodontolYear: 20053212515642052
27. Tajima Y,Kuroda-Kawasaki M,Ohno J,Yi J,Kusama K,Tanaka H. Peripheral ameloblastoma with potentially malignant features: report of a case with special regard to its keratin profileJ Oral Pathol MedYear: 200130494811545241
28. Redman RS,Keegan BP,Spector CJ,Patterson RH. Peripheral ameloblastoma with unusual mitotic activity and conflicting evidence regarding histogenesisJ Oral Maxillofac SurgYear: 19945219278295058
29. Siar CH,Lau SH,Ng KH. Ameloblastoma of the jaws: a retrospective analysis of 340 cases in a Malaysian populationJ Oral Maxillofac SurgYear: 2012706081521723654
30. Koukourakis GV,Miliadou A,Sotiropoulou-Lontou A. Ameloblastoma, a rare benign odontogenic tumour: an interesting tumour review targeting the role of radiation therapyClin Transl OncolYear: 201113793722082643
31. Wettan HL,Patella PA,Freedman PD. Peripheral ameloblastoma: review of the literature and report of recurrence as severe dysplasiaJ Oral Maxillofac SurgYear: 200159811511429748
32. Baden E,Doyle JL,Petriella V. Malignant transformation of peripheral ameloblastomaOral Surg Oral Med Oral PatholYear: 19937521498426721
33. Batsakis JG,McClatchey KD. Ameloblastoma of the maxilla and peripheral ameloblastomasAnn Otol Rhinol LaryngolYear: 1983925326625456
34. Schaberg SJ,Antimarino RF,Pierce GL,Crawford BE. Peripheral ameloblastoma. Report of a caseInt J Oral SurgYear: 19831234476420360
35. Patrikiou A,Papanicolaou S,Stylogianni E,Sotiriadou S. Peripheral ameloblastoma. Case report and review of the literatureInt J Oral SurgYear: 1983125156406378
36. Hernandez G,Sanchez G,Caballero T,Moskow BS. A rare case of a multicentric peripheral ameloblastoma of the gingiva. A light and electron microscopic studyJ Clin PeriodontolYear: 19921928171569230
37. Califano L,Maremonti P,Boscaino A,De Rosa G,Giardino C. Peripheral ameloblastoma: report of a case with malignant aspectBr J Oral Maxillofac SurgYear: 19963424028818258
38. Yanamoto S,Yamabe S,Kawasaki G,Mizuno A. Peripheral Ameloblastoma in the Maxillary Canine RegionAsian J Oral Maxillofac SurgYear: 2005171958
39. Martelli-Junior H,Souza LN,Santos LA,Melo-Filho MR,De Paula AM. Peripheral ameloblastoma: a case reportOral Surg Oral Med Oral Pathol Oral Radiol EndodYear: 200599E31315829867
40. LeCorn DW,Bhattacharyya I,Vertucci FJ. Peripheral ameloblastoma: a case report and review of the literatureJ EndodYear: 200632152416427467
41. Gomes CC,Garcia BG,Gomez RS,de Freitas JB,Mesquita RA. A clinical case of peripheral ameloblastomaBraz J Oral SciYear: 2007613646


[Figure ID: F1]
Figure 1 

a) Macroscopic aspect of the lesion; b) Hematoxylin-eosin, 40X. The tumor shows a plexiform pattern. It consists of island and strands of odontogenic epithelium within a fibrous stroma. The basal cells of these stands are columnar, hyperchromatic and lined up in a palisaded fashion; c) 40X. Tumor positivity for CK14; d) 40X. Tumor positivity for CK19; e) 40X. Tumor positivity for CKAE1-3; f) 40X. Expression of podoplanin is evident in peripheral cuboidal neoplastic cells of tumor nests and it is expressed slightly in central stellate reticulum-like cells.

[TableWrap ID: T1] Table 1  Reported cases of peripheral ameloblastoma of upper gingiva.

Article Categories:
  • Case Report
    • Oral Medicine and Pathology

Previous Document:  Salivary and crevicular fluid interleukins in gingivitis.
Next Document:  Replantation of a maxillary second molar after removal of a third molar with a dentigerous cyst: Cas...