- Email: [email protected]
Ameloblastic fibro-odontoma in mandibular molar region: A case report
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
Available online at www.sciencedirect.com
Pediatric Dental Journal journal homepage: www.elsevier.com/locate/pdj
Case Report
Ameloblastic fibro-odontoma in mandibular molar region: A case report Masatoshi Otsugu, Rena Okawa*, Ryota Nomura, Kazuhiko Nakano Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan
article info
abstract
Article history:
We report a case of ameloblastic fibro-odontoma (AFO) in the mandibular molar region. A
Received 28 August 2018
Japanese boy aged 6 years 8 months visited the Pediatric Dentistry Clinic of Osaka Uni-
Received in revised form
versity Dental Hospital with dental caries as the chief complaint. Radiography revealed a
7 November 2018
well-defined homogenous mixed radiopaque mass like dentition above the crown of the
Accepted 18 December 2018
mandibular left first molar. At the age of 6 years 9 months, enucleation of the tumor mass
Available online 4 January 2019
was performed under local anesthesia. Based on the histological findings, the diagnosis was AFO. Following enucleation, the left first molar showed a tendency for eruption.
Keywords:
© 2018 Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.
Ameloblastic fibro-odontoma Odontoma Mandible
1.
Introduction
Ameloblastic fibro-odontoma (AFO) is a benign, mixed odontogenic tumor that commonly occurs in the first and second decades of life, with no significant gender inclination [1] and usually found in a posterior area rather than anterior area [2]. Clinically, this tumor is generally characterized as a painless swelling and slow growing mass with delayed tooth eruption [1]. Radiography findings show a well-defined radiolucent area containing various amounts of radiopaque material of irregular size and form [3]. Histologically, the tumor is composed of soft and hard tissues, with the soft tissue component is composed of epithelial strands and small islands of odontogenic epithelium, and the hard tissue component is composed of enamel and dentin [2]. Differential diagnosis of an AFO
includes odontoma and ameloblastic fibroma [2,4,5]. AFO represents less than 3% of all odontogenic tumours [4], and approximately 1% among Japanese individuals [6]. Furthermore, there is little potential for recurrence of AFO [2,5,7,8]. Here, we present details of a rare case of AFO in the mandibular molar in a Japanese boy.
2.
Case report
A Japanese boy aged 6 years 8 months visited the Pediatric Dentistry Clinic of Osaka University Dental Hospital with dental caries as the chief complaint. Panoramic radiography performed for investigation of caries incidentally revealed a radiopaque lesion in the area of the left first mandibular molar
* Corresponding author. Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka 565-0871, Japan. E-mail address: [email protected] (R. Okawa). https://doi.org/10.1016/j.pdj.2018.12.002 0917-2394/© 2018 Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.
38
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
as well as a congenital defect of the left second mandibular molar (Fig. 2). Thereafter, cone-beam computed tomography (CBCT) was performed, which showed various amounts of radiopaque material of irregular size and form within a welldefined radiolucent area (Fig. 3). The degree of completion of root formation of the unerupted first molar was approximately 30% and the lesion had displaced the tooth in an inferior direction. Intraoral examination findings included dental caries in the primary molars and no eruption of the first molars, though no diffuse swelling in the gingiva distal of the left primary first molar was noted (Fig. 1). An extraoral examination also revealed no obvious abnormality such as swelling or facial asymmetry. There was no history of paresthesia or pain, and medical, social, and family histories were unremarkable. We initially suspected a complex odontoma in the molar area of the left mandible.
At the age of 6 years 9 months, under local anesthesia, a gingivectomy was performed for clearing with a radio knife, followed by enucleation of the lesion and fenestration without bone elimination. A tooth-like calcified mass approximately 15 mm in diameter was removed. After enucleation, the wound was kept open to induce eruption of the left first molar. The resected specimen was examined with hematoxylin and eosin (H-E) staining (Fig. 4). Microscopic findings revealed that half of the resected specimen was occupied by the hard tissue composed of enamel, dentin, and cementum arranged in a disorderly manner. The hard tissue was surrounded by the sparse mesenchymal fibrous tissue like dentin papilla. In the mesenchymal tissue, epithelial islands, as well as alveolar tissue like enamel organ and dental lamina were noted. The tumor was finally diagnosed as an AFO.
Fig. 1 e Findings of intraoral examination at first visit to our pediatric clinic (age 6 years 8 months).
Fig. 2 e Panoramic radiograph findings at first visit to our pediatric clinic (age 6 years 8 months). Arrow indicates radiopaque lesion.
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
39
Fig. 3 e CBCT image of lesion at first visit to our pediatric clinic (age 6 years 8 months). (A) Sagittal CT image (B) Coronal CT image (C) Axial CT image. Arrows indicate radiopaque lesion.
At 9 months after enucleation, the unerupted left first molar showed a tendency for eruption in panoramic radiograph findings (Figs. 5 and 6). In follow-up examinations performed for 1 year 4 months after the procedure, no AFO recurrence was seen.
3.
Discussion
AFO is a benign, expansile, mixed odontogenic tumor [6] and represents approximately 1e3% of odontogenic tumours [9]. According to the 2005 WHO classification of odontogenic tumor, AFO belonged to the family of mixed odontogenic tumours, and was distinguished from invasive ameloblastoma
and odontoma as well as 1971 WHO classification [10,11]. It was also defined as a neoplasm consisting of odontogenic mesenchyme resembling the dental papilla, and epithelial nests resembling the dental lamina and enamel organ [10]. The 2017 WHO classification noted that AFO in most cases represent developmental stages of either a complex or compound odontoma [12]. Bucher presented 114 well-documented cases, in which patient age ranged from 8 months to 26 years (mean 9.6 years), with 65% occurring in males and 65% located in the mandible, nearly 80% in the posterior region [2]. An AFO is usually manifested as a unilocular lesion (90.3%), with multilocular formation an uncommon finding (9.7%), and most diagnosed lesions are described as mixed radiolucentradiopaque (94.8%), while only a few are radiolucent (5.2%)
40
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
Fig. 4 e Histological findings of resected specimen (H-E staining). (A) Low-magnification image; E: the hard tissue composed of enamel, D: hard tissue composed of dentin, C: hard tissue composed of cementum. Arrow indicates range of hypertrophic mesenchymal tissue. (B) Highmagnification image of area outlined in the lowmagnification image. Arrows indicate epithelial islands.
[2]. The ratio of radiopaque to radiolucent areas varies from rich to poor and some of these tumours resemble odontomas in radiography results [10,11]. A complex odontoma appears as an irregular mass of calcified material surrounded by a thin radiolucent area with a smooth periphery [13], thus we initially suspected the lesion in the present case to be an odontoma. Histological findings of the present case showed that half of the resected specimen was occupied by hard tissue composed of enamel, dentin, and cementum arranged in a disorderly manner. The hard tissue was surrounded by a sparse mesenchyme like dental papilla. In the mesenchymal fibrous tissue, epithelial islands, as well as alveolar tissue like enamel organ and dental lamina were noted. Mesenchymal fibrous tissue differentiation was different from that of a developing complex odontoma, thus the diagnosis was AFO. The clinical features of most AFO lesions are associated with asymptomatic swelling and delayed tooth eruption in the affected region. In many cases as well as the present, the lesion displaces erupted teeth and can also cause delayed tooth eruption [14]. Other features resemble a complex odontoma. Remarkable symptoms such as pain and paresthesia are uncommon, and most of these lesions are incidentally discovered in radiographic findings. Therefore, the possibility of the existence of such a tumor must be taken into consideration when performing a panoramic radiological examination for another purpose such as caries evaluation, as in the present case. At the time of writing the patient has been receiving regular periodic check-up examinations for a period of 1 year 4 months until the age of 8 years and is symptom free. At 9 months after enucleation of the lesion (age 7 years 1 month), panoramic radiography showed a tendency of eruption of the unerupted left first molar and growth of the root of that tooth. The prognosis of affected patients is generally good and recurrence is highly unusual, though a few cases of malignant transformation have been reported [15], thus long-term follow-up is important.
Fig. 5 e Follow-up intraoral examination findings after 9 months (age 7 years 5 months).
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
41
Fig. 6 e Follow-up panoramic radiography findings after 9 months (age 7 years 5 months).
Conflicts of interest None of the authors have conflicts of interest to declare in regard to this study.
references
[1] Gantana R, Gotoor SG, Kumar RV, Munisekhar MS. Ameloblastic fibro-odontoma. BMJ Case Rep 2015. https:// doi.org/10.1136/2015/209739. [2] Buchner A, Kaffe I, Vered M. Clinical and radiological profile of ameloblastic fibro- odontoma: an update on an uncommon odontogenic tumor based on a critical analysis of 114 cases. Head Neck Pathol 2013;7:54e63. [3] Surej Kumar LK, Manuel S, Khalam SA, Venugopal K, Kivakumar TT, Issac J. Ameloblastic fibro-odontoma. Int J Surg Case Rep 2014;5:1142e4. [4] Nelson BL, Thompson Lester DR. Ameloblastic fibroodontoma. Head Neck Pathol 2014;8:168e70. € kel KT. Recurrent [5] Fridrich RE, Siegert J, Donath K, Ja ameloblastic fibro-odontoma in a 10-year-old boy. J Oral Maxillofac Surg 2001;59:1362e6. [6] Sukegawa S, Nakano K, Kanno T, Kawai H, Matsumoto K, Sukagawa-Takahashi Y, et al. Pathological and clinical study of Japanese fibro-odontomas. J Hard Tissue Biol 2017;26(4):425e30.
[7] Furst I, Pharoah M, Phillips J. Recurrence of an ameloblastic fibro-odontoma in a 9-year-old boy. J Oral Maxillofac Surg 1999;57(5):620e3. [8] Chen Y, Li TJ, Gao Y, Yu SF. Ameloblastic fibroma and related lesions: a clinicopathologic study with reference to their nature and interrelationship. J Oral Pathol Med 2005;34:588e95. [9] Araki M, Namiki S, Amemiya T, Matsumoto K, Honda K, Yonehara Y, et al. Diverse calcification patterns of ameloblastic fibro-odontoma on radiographic examination. J Oral Sci 2016;58:533e7. [10] Barnes L, Eveson JW, Reichart P, Sidransky D. Pathology and genetics of head and neck tumours (WHO classification of tumours). Chapter 6: Odontogenic tumours. Lyon: IARC; 2005. p. 308e9. [11] Pindborg JJ, Kramer IR. Histological typing of odontogenic tumors, jaw cyst, and allied lesion. Geneva: WHO; 1971. p. 18e27. [12] EL-Naggar Chan JKC, Grandis JR, Takata T, Slootweg PJ. WHO classification of head and neck tumours. Chapter 8: Odontogenic and maxilofacial bone tumours. Lyon: IARC; 2017. p. 205e60. [13] Girish G, Bavle RM, Singh MK, Prasad SN. Compound composite odontoma. J Oral Maxillofac Pathol 2016;20:162. [14] Shimomura E, Iwabuchi H, Uchiyama K, Tanaka Y. A case of ameloblastic fibro- odontoma in a mandibular molar. A review of the literature on differences from developing odontoma. Jpn J Oral Maxillofac Surg 2003;49:218e21. [15] Howell RM, Burkes Jr EJ. Malignant transformation of ameloblastic fibro-odontoma to ameloblastic fibrosarcoma. Oral Surg Oral Med Oral Pathol 1977;43:391e401.
Available online at www.sciencedirect.com
Pediatric Dental Journal journal homepage: www.elsevier.com/locate/pdj
Case Report
Ameloblastic fibro-odontoma in mandibular molar region: A case report Masatoshi Otsugu, Rena Okawa*, Ryota Nomura, Kazuhiko Nakano Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan
article info
abstract
Article history:
We report a case of ameloblastic fibro-odontoma (AFO) in the mandibular molar region. A
Received 28 August 2018
Japanese boy aged 6 years 8 months visited the Pediatric Dentistry Clinic of Osaka Uni-
Received in revised form
versity Dental Hospital with dental caries as the chief complaint. Radiography revealed a
7 November 2018
well-defined homogenous mixed radiopaque mass like dentition above the crown of the
Accepted 18 December 2018
mandibular left first molar. At the age of 6 years 9 months, enucleation of the tumor mass
Available online 4 January 2019
was performed under local anesthesia. Based on the histological findings, the diagnosis was AFO. Following enucleation, the left first molar showed a tendency for eruption.
Keywords:
© 2018 Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.
Ameloblastic fibro-odontoma Odontoma Mandible
1.
Introduction
Ameloblastic fibro-odontoma (AFO) is a benign, mixed odontogenic tumor that commonly occurs in the first and second decades of life, with no significant gender inclination [1] and usually found in a posterior area rather than anterior area [2]. Clinically, this tumor is generally characterized as a painless swelling and slow growing mass with delayed tooth eruption [1]. Radiography findings show a well-defined radiolucent area containing various amounts of radiopaque material of irregular size and form [3]. Histologically, the tumor is composed of soft and hard tissues, with the soft tissue component is composed of epithelial strands and small islands of odontogenic epithelium, and the hard tissue component is composed of enamel and dentin [2]. Differential diagnosis of an AFO
includes odontoma and ameloblastic fibroma [2,4,5]. AFO represents less than 3% of all odontogenic tumours [4], and approximately 1% among Japanese individuals [6]. Furthermore, there is little potential for recurrence of AFO [2,5,7,8]. Here, we present details of a rare case of AFO in the mandibular molar in a Japanese boy.
2.
Case report
A Japanese boy aged 6 years 8 months visited the Pediatric Dentistry Clinic of Osaka University Dental Hospital with dental caries as the chief complaint. Panoramic radiography performed for investigation of caries incidentally revealed a radiopaque lesion in the area of the left first mandibular molar
* Corresponding author. Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka 565-0871, Japan. E-mail address: [email protected] (R. Okawa). https://doi.org/10.1016/j.pdj.2018.12.002 0917-2394/© 2018 Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.
38
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
as well as a congenital defect of the left second mandibular molar (Fig. 2). Thereafter, cone-beam computed tomography (CBCT) was performed, which showed various amounts of radiopaque material of irregular size and form within a welldefined radiolucent area (Fig. 3). The degree of completion of root formation of the unerupted first molar was approximately 30% and the lesion had displaced the tooth in an inferior direction. Intraoral examination findings included dental caries in the primary molars and no eruption of the first molars, though no diffuse swelling in the gingiva distal of the left primary first molar was noted (Fig. 1). An extraoral examination also revealed no obvious abnormality such as swelling or facial asymmetry. There was no history of paresthesia or pain, and medical, social, and family histories were unremarkable. We initially suspected a complex odontoma in the molar area of the left mandible.
At the age of 6 years 9 months, under local anesthesia, a gingivectomy was performed for clearing with a radio knife, followed by enucleation of the lesion and fenestration without bone elimination. A tooth-like calcified mass approximately 15 mm in diameter was removed. After enucleation, the wound was kept open to induce eruption of the left first molar. The resected specimen was examined with hematoxylin and eosin (H-E) staining (Fig. 4). Microscopic findings revealed that half of the resected specimen was occupied by the hard tissue composed of enamel, dentin, and cementum arranged in a disorderly manner. The hard tissue was surrounded by the sparse mesenchymal fibrous tissue like dentin papilla. In the mesenchymal tissue, epithelial islands, as well as alveolar tissue like enamel organ and dental lamina were noted. The tumor was finally diagnosed as an AFO.
Fig. 1 e Findings of intraoral examination at first visit to our pediatric clinic (age 6 years 8 months).
Fig. 2 e Panoramic radiograph findings at first visit to our pediatric clinic (age 6 years 8 months). Arrow indicates radiopaque lesion.
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
39
Fig. 3 e CBCT image of lesion at first visit to our pediatric clinic (age 6 years 8 months). (A) Sagittal CT image (B) Coronal CT image (C) Axial CT image. Arrows indicate radiopaque lesion.
At 9 months after enucleation, the unerupted left first molar showed a tendency for eruption in panoramic radiograph findings (Figs. 5 and 6). In follow-up examinations performed for 1 year 4 months after the procedure, no AFO recurrence was seen.
3.
Discussion
AFO is a benign, expansile, mixed odontogenic tumor [6] and represents approximately 1e3% of odontogenic tumours [9]. According to the 2005 WHO classification of odontogenic tumor, AFO belonged to the family of mixed odontogenic tumours, and was distinguished from invasive ameloblastoma
and odontoma as well as 1971 WHO classification [10,11]. It was also defined as a neoplasm consisting of odontogenic mesenchyme resembling the dental papilla, and epithelial nests resembling the dental lamina and enamel organ [10]. The 2017 WHO classification noted that AFO in most cases represent developmental stages of either a complex or compound odontoma [12]. Bucher presented 114 well-documented cases, in which patient age ranged from 8 months to 26 years (mean 9.6 years), with 65% occurring in males and 65% located in the mandible, nearly 80% in the posterior region [2]. An AFO is usually manifested as a unilocular lesion (90.3%), with multilocular formation an uncommon finding (9.7%), and most diagnosed lesions are described as mixed radiolucentradiopaque (94.8%), while only a few are radiolucent (5.2%)
40
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
Fig. 4 e Histological findings of resected specimen (H-E staining). (A) Low-magnification image; E: the hard tissue composed of enamel, D: hard tissue composed of dentin, C: hard tissue composed of cementum. Arrow indicates range of hypertrophic mesenchymal tissue. (B) Highmagnification image of area outlined in the lowmagnification image. Arrows indicate epithelial islands.
[2]. The ratio of radiopaque to radiolucent areas varies from rich to poor and some of these tumours resemble odontomas in radiography results [10,11]. A complex odontoma appears as an irregular mass of calcified material surrounded by a thin radiolucent area with a smooth periphery [13], thus we initially suspected the lesion in the present case to be an odontoma. Histological findings of the present case showed that half of the resected specimen was occupied by hard tissue composed of enamel, dentin, and cementum arranged in a disorderly manner. The hard tissue was surrounded by a sparse mesenchyme like dental papilla. In the mesenchymal fibrous tissue, epithelial islands, as well as alveolar tissue like enamel organ and dental lamina were noted. Mesenchymal fibrous tissue differentiation was different from that of a developing complex odontoma, thus the diagnosis was AFO. The clinical features of most AFO lesions are associated with asymptomatic swelling and delayed tooth eruption in the affected region. In many cases as well as the present, the lesion displaces erupted teeth and can also cause delayed tooth eruption [14]. Other features resemble a complex odontoma. Remarkable symptoms such as pain and paresthesia are uncommon, and most of these lesions are incidentally discovered in radiographic findings. Therefore, the possibility of the existence of such a tumor must be taken into consideration when performing a panoramic radiological examination for another purpose such as caries evaluation, as in the present case. At the time of writing the patient has been receiving regular periodic check-up examinations for a period of 1 year 4 months until the age of 8 years and is symptom free. At 9 months after enucleation of the lesion (age 7 years 1 month), panoramic radiography showed a tendency of eruption of the unerupted left first molar and growth of the root of that tooth. The prognosis of affected patients is generally good and recurrence is highly unusual, though a few cases of malignant transformation have been reported [15], thus long-term follow-up is important.
Fig. 5 e Follow-up intraoral examination findings after 9 months (age 7 years 5 months).
p e d i a t r i c d e n t a l j o u r n a l 2 9 ( 2 0 1 9 ) 3 7 e4 1
41
Fig. 6 e Follow-up panoramic radiography findings after 9 months (age 7 years 5 months).
Conflicts of interest None of the authors have conflicts of interest to declare in regard to this study.
references
[1] Gantana R, Gotoor SG, Kumar RV, Munisekhar MS. Ameloblastic fibro-odontoma. BMJ Case Rep 2015. https:// doi.org/10.1136/2015/209739. [2] Buchner A, Kaffe I, Vered M. Clinical and radiological profile of ameloblastic fibro- odontoma: an update on an uncommon odontogenic tumor based on a critical analysis of 114 cases. Head Neck Pathol 2013;7:54e63. [3] Surej Kumar LK, Manuel S, Khalam SA, Venugopal K, Kivakumar TT, Issac J. Ameloblastic fibro-odontoma. Int J Surg Case Rep 2014;5:1142e4. [4] Nelson BL, Thompson Lester DR. Ameloblastic fibroodontoma. Head Neck Pathol 2014;8:168e70. € kel KT. Recurrent [5] Fridrich RE, Siegert J, Donath K, Ja ameloblastic fibro-odontoma in a 10-year-old boy. J Oral Maxillofac Surg 2001;59:1362e6. [6] Sukegawa S, Nakano K, Kanno T, Kawai H, Matsumoto K, Sukagawa-Takahashi Y, et al. Pathological and clinical study of Japanese fibro-odontomas. J Hard Tissue Biol 2017;26(4):425e30.
[7] Furst I, Pharoah M, Phillips J. Recurrence of an ameloblastic fibro-odontoma in a 9-year-old boy. J Oral Maxillofac Surg 1999;57(5):620e3. [8] Chen Y, Li TJ, Gao Y, Yu SF. Ameloblastic fibroma and related lesions: a clinicopathologic study with reference to their nature and interrelationship. J Oral Pathol Med 2005;34:588e95. [9] Araki M, Namiki S, Amemiya T, Matsumoto K, Honda K, Yonehara Y, et al. Diverse calcification patterns of ameloblastic fibro-odontoma on radiographic examination. J Oral Sci 2016;58:533e7. [10] Barnes L, Eveson JW, Reichart P, Sidransky D. Pathology and genetics of head and neck tumours (WHO classification of tumours). Chapter 6: Odontogenic tumours. Lyon: IARC; 2005. p. 308e9. [11] Pindborg JJ, Kramer IR. Histological typing of odontogenic tumors, jaw cyst, and allied lesion. Geneva: WHO; 1971. p. 18e27. [12] EL-Naggar Chan JKC, Grandis JR, Takata T, Slootweg PJ. WHO classification of head and neck tumours. Chapter 8: Odontogenic and maxilofacial bone tumours. Lyon: IARC; 2017. p. 205e60. [13] Girish G, Bavle RM, Singh MK, Prasad SN. Compound composite odontoma. J Oral Maxillofac Pathol 2016;20:162. [14] Shimomura E, Iwabuchi H, Uchiyama K, Tanaka Y. A case of ameloblastic fibro- odontoma in a mandibular molar. A review of the literature on differences from developing odontoma. Jpn J Oral Maxillofac Surg 2003;49:218e21. [15] Howell RM, Burkes Jr EJ. Malignant transformation of ameloblastic fibro-odontoma to ameloblastic fibrosarcoma. Oral Surg Oral Med Oral Pathol 1977;43:391e401.