Ameloblastic Fibro-Odontoma: A Case Report

Case Report
DOI: 10.17354/cr/2015/104
Ameloblastic Fibro-Odontoma: A Case Report
Satya Ranjan Misra1, Pavitra Baskaran2, G Maragathavalli3, R Mithra2, N M Praveena4
Reader, Department of Oral Medicine and Radiology, Institute of Dental Sciences, Bhubaneshwar, Odisha, India, 2Reader, Department of Oral
Medicine and Radiology, Meenakshi Ammal Dental College, Chennai, Tamil Nadu, India, 3Professor, Department of Oral Medicine and Radiology,
Saveetha Dental College, Chennai, Tamil Nadu, India, 4Reader, Department of Oral Medicine and Radiology, Thai Moogambigai Dental College,
Chennai, Tamil Nadu, India
1
Ameloblastic fibro-odontoma (AFO) is an uncommon benign odontogenic tumor with histologic features similar to that of ameloblastic
fibroma, but with inductive changes that lead to the formation of enamel and dentin. Among the odontogenic tumors, the incidence varies
from 0.3% to 1.7%, reaching 4.6% when only the cases of children are considered. AFO presents as a painless swelling mostly in the posterior
portion of the maxilla or mandible. Radiographs show the radiolucent area containing various amounts of radiopaque material of irregular
size and form. This case report describes AFO affecting the 21-year-old woman. The lesion was surgically excised, and no recurrence was
observed on follow-up.
Keywords: Ameloblastic fibro-odontoma, Fibro-odontoma, Odontogenic tumor
of radiopaque material of irregular size and form.7 This
report describes an AFO in a 21-year-old woman.
INTRODUCTION
Odontogenic tumors are a heterogenous group of diseases
ranging from hamartomas to benign and malignant
neoplasms.1 Ameloblastic fibro-odontoma (AFO) is a rare
benign, slow growing, expansile epithelial odontogenic tumor
with odontogenic mesenchyme. The term AFO was first used
by Hooker in 1967.2 AFO was originally termed as ameloblastic
odontomas but in 1971, World Health Organization (WHO)
suggested that this term is inappropriate since it encompasses
two types of odontogenic tumors that are different in their
histologic and biologic behavior.3 It is defined by WHO as a
neoplasm composed of proliferating odontogenic epithelium
embedded in a cellular ectomesenchymal tissue that resembles
dental papilla, and with varying degrees of inductive change
and dental hard tissue formation.4
A majority of AFO is intraosseous and is associated with
unerupted teeth. It is reported that approximately 80% of
the lesions were located in the posterior area of the jaws,
and most (58%) were in the posterior mandible.5 54% of AFO
are found in the posterior mandible.6 Radiographs show a
well-defined radiolucent area containing various amounts
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CASE REPORT
A 21 years female patient reported to the dental hospital
with a swelling in the right side of her face for 2 weeks.
History revealed that the swelling was slowly growing in
size and was painless. The medical, personal, and family
history was non-contributory.
A diffuse swelling was seen in the right body of mandible
region, with ill-defined margins (Figure 1). The swelling
was soft in consistency. Intraorally the swelling was
observed obliterating the buccal sulcus in 46, 47 regions.
It was fluctuant, non-tender, and fixed to the underlying
bone. Correlating the history and clinical findings, a clinical
diagnosis of the odontogenic cyst was made.
Following the clinical diagnosis, patient was subjected to
the following investigations. Periapical radiograph was
taken which revealed a well-defined, unilocular, interradicular radiolucency with a hyperostotic border was seen
between the distal root of 46 and mesial root of 47 (Figure 2).
Mandibular right lateral occlusal radiograph showed
the expansion of the lingual cortex (Figure 3). Panoramic
radiograph revealed a well-defined, ovoid, unilocular,
inter-radicular radiolucency with a hyperostotic border
measuring 1 cm in greatest diameter (Figure 4). Correlating
the clinical and radiographic findings, a radiologic diagnosis
of lateral periodontal cyst was made.
Corresponding Author:
Dr. Pavitra Baskaran, Department of Oral Medicine and Radiology, Meenakshi Ammal Dental College, Chennai - 600 082, Tamil Nadu, India.
E-mail: pavitramds2008@gmail.com
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Misra, et al.: Ameloblastic Fibro-odontoma
Aspiration of the cystic content was made, and a straw
colored fluid was obtained on aspiration. Excisional
biopsy was performed and Hematoxylin–Eosin (H and E)
stained section revealed narrow cords and small discrete
islands of odontogenic epithelium with loose primitive
connective tissue resembling dental papilla (Figure 5a).
There were areas showing primitive mesenchyme with
mild basophilia and angular fibroblasts (Figure 5b) and
odontogenic islands with eosinophilic rimming resembling
dentinoid (Figure 5c). Odontogenic islands show peripheral
columnar cells resembling ameloblasts, which surround a
mass of loosely arranged epithelial cells resembling stellate
reticulum (Figure 5d). All the above histologic features were
suggestive of ameloblastic fibrodontoma.
The lesion was treated by complete surgical excision. The
patient was followed up for 6 months without any signs
of recurrence.
DISCUSSION
Figure 1: A diffuse swelling was seen in the right body of mandible region, with
ill-defined margins
Figure 2: A well-defined, unilocular, inter-radicular radiolucency with a
hyperostotic border was seen between the distal root of 46 and mesial root of 47
Figure 3: Mandibular right lateral occlusal radiograph showed expansion of
the lingual cortex
2
AFO is a rare odontogenic tumor of childhood and
adolescence.6 It is seen in young patients, with the mean
age of 11.5 years.7 In general, it is seen in the first and
second decades of life, which might also be a characteristic
of the lesion. However, AFO may also occur at advanced
Figure 4: Panoramic Radiograph revealed a well-defined, ovoid, unilocular,
inter-radicular radiolucency with a hyperostotic border
a
b
c
d
Figure 5: (a-d) Hematoxylin-eosin stained section revealed narrow cords
and small discrete islands of odontogenic epithelium with loose primitive
connective tissue resembling dental papilla. There were areas showing primitive
mesenchyme with mild basophilia and angular fibroblasts and odontogenic islands
with eosinophilic rimming resembling dentinoid
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Misra, et al.: Ameloblastic Fibro-odontoma
ages. Previously, Philipsen et al. declared that the mean age
of AFO cases falls when compared with the ameloblastic
fibroma (AF) and AF-dentinoma, supporting the suggestion
that age is a critical feature in AFO diagnosis.8 The frequency
of occurrence of AFO is about 1-3% considering all
odontogenic tumors.9 The two main complaints are swelling
and failure of tooth eruption. Clinically, it presents as a
painless swelling of the affected area and is usually seen
in the posterior maxilla or mandible as seen in our case.7
Radiographically, most authors state that it presents as
a unilocular or multilocular lesion.4 AFO appears as a
radiolucent area that consists of the variable amount of
calcified material.2 The center shows a radiopacity irregular
in shape and density or may present as homogenous
rounded calcified mass. 10 The ratio of radiopaque to
radiolucent areas differs from one lesion to another,
sometimes the mineralized elements in the tumor
predominate and the lesion may be radiographically similar
to that of an odontoma.4
A diagnosis of AFO is given when the lesion presents with
typical age, location, and radiographic pattern. Differential
diagnosis of AFO based on mixed radiographic patterns
includes lesions such as calcifying epithelial odontogenic
tumor, calcifying odontogenic cysts, immature complex
odontoma, and adenomatoid odontogenic tumor.7
Histologically, AFO is composed of strands, cords, and
islands of odontogenic epithelium embedded in a cell
rich, primitive ectomesenchyme that resembles the dental
papilla. Dentin and enamel matrix are also seen.11 Our case
reported here is consistent with the above findings.
Histopathological differential diagnosis also includes
AF, ameloblastic fibro-dentinoma. However, AF and
AFO are believed to be stages of complex odontoma
formation. Cahn and Blum postulated that AF develops
first into moderately differentiated form, following AFO,
and eventually into a complex odontoma. The concept
of a continuum of differentiation is not widely accepted,
with other researchers suggesting that they are separate
pathologic entities. AFO exists as a distinct entity, but
histologically it is indistinguishable from immature complex
odontoma.12 However, AFO differs significantly from the
hamartomatous odontoma by having a greater potential
for growth and causing considerable deformity, bone
destruction.4
It is not possible to distinguish hamartoma from neoplasm
based on histological features alone.13 Philipsen and Reichart
(1997) suggested a hypothesis regarding pathogenesis.
Most mixed odontogenic tumors are considered to be
hamartomatous in nature and are a part of compound
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odontoma line. AF or fibro-dentinoma is the first step
in developing compound odontome. These tumors can
develop further in the second stage of AFO. The final stage
is the fully mineralized complex odontoma with high degree
of histomorphologic differentiation.1
The presence of dentin and enamel matrix is the feature that
separates the AFO from AF. The amount of mineralized
products of odontogenesis may vary from being easily seen
on grossing to require serial sectioning to identify dentin
and enamel matrix microscopically.14
AFO shows dental structures resembling dentine, but also
because it contains enamel-like tissues. Thus, the formation
of AFO might be based on enamel matrix production,
which is one of the most important features of the lesion
differentiating it from ameloblastic fibro-dentinoma.8
The treatment of AFO is by conservative surgical
enucleation. However, if the lesions are larger, it may
require surgical resection of either partial maxillectomy or
partial mandibulectomy.2
Recurrence of AFO is not common. Some authors have
reported recurrence in cases where the impacted or retained
teeth have been preserved.11 The recurrence is governed by
the degree of involvement of impacted tooth by the tumor
and the difficulty to completely remove the lesion.15,16 In the
present case, no recurrence was reported after the surgical
excision that was followed up after 6 months.
CONCLUSION
AFO is a rare benign odontogenic tumor that emphasizes
the importance of radiologic examination in early detection.
Although rare, AFO should be considered in the differential
diagnosis of intra-oral radiolucencies that contain
radiopaque material.
REFERENCES
1. Shetty DC, Aadithya B, Ahuja P, Hallikeri K, Paul M. Ameloblastic
fibro-odontome case report: Diagnostic valuable aid of CT scan in
identification of mineralized component. JIAOMR 2010;22:102-4.
2. Sivapathasundharam B, Manikandhan R, Sivakumar G, George T.
Ameloblastic fibro odontoma.
3. Indian J Dent Res 2005;16:19-21.
4. 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;7:54-63.
5. Nanda KD, Marwaha M. Ameloblastic fibro-odontoma
masquerading as odontoma. Indian J Dent Res 2011;22:616.
6. Lin YC, Hsu HM, Liu CS, Yuan K. A peripheral ameloblastic fibroodontoma in a 3-year-old girl: Case report, immunohistochemical
analysis, and literature review. Case Rep Dent 2014;2014:321671.
7.Reichart PA, Philipsen HP, Gelderblom HR, Stratmann U.
3
Misra, et al.: Ameloblastic Fibro-odontoma
8.
9.
10.
11.
12.
4
Ameloblastic fibro-odontoma- report of two cases with
ultrastructural study of tumor dental hard structures. Oral Oncol
2004;40:8-12.
Carvalho Silva GC, Jham BC, Carvalho Silva E, Horta CR,
Godinho SH, Gomez RS. Ameloblastic fibro-odontoma. Oral Oncol
Extra 2006;42:217-20.
Nayak B, Patankar S, Khot K, Shobha BV, Sharma G. Ameloblastic
fibro-odontoma of the maxilla: Review of literature and report of
a case. JIAOMR 2011;23:S442-4.
Sreenath G, Reddy YI, Srrenivasreddy P, Prakash AR. Ameloblastic
fibro-odontome (AFO) of the mandible: A case report. J Clin Diagn
Res 2014;8:260-2.
Chang H, Precious DS, Shimizu MS. Ameloblastic fibro-odontoma:
A case report. J Can Dent Assoc 2002;68:243-6.
Surej Kumar LK, Manuel S, Khalam SA, Venugopal K,
Sivakumar TT, Issac J. Ameloblastic fibro-odontoma. Int J Surg
Case Rep 2014;5:1142-4.
13. de Souza Tolentino E, Centurion BS, Lima MC, Freitas-Faria P,
Consolaro A, Sant’ana E. Ameloblastic fibro-odontoma: A diagnostic
challenge. Int J Dent 2010;2010. pii: 104630.
14. Dolanmaz D, Pampu AA, Kalayci A, Etöz OA, Atici S. An unusual
size of ameloblastic fibro-odontoma. Dentomaxillofac Radiol
2008;37:179-82.
15. Nelson BL, Thompson LD. Ameloblatic fibro-odontoma. Head
Neck Pathol 2014;8(2):168-170.
16. Reis SR, de Freitas CE, do Espírito Santo AR. Management of
ameloblastic fibro-odontoma in a 6-year-old girl preserving the
associated impacted permanent tooth. J Oral Sci 2007;49:331-5.
How to cite this article: Misra SR, Baskaran P, Maragathavalli G, Mithra R,
Praveena NM. Ameloblastic Fibro-Odontoma: A Case Report. IJSS Case
Reports & Reviews 2015;2(2):1-4.
Source of Support: Nil, Conflict of Interest: None declared.
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