Applied Cancer Research 2008;28(1):37-40
Case Report
Recurrent Ameloblastoma after 33 years of Hemimandibulectomy:
Case Report
Pietro Mainenti, DDS, MS;1, 2 Gustavo Saggioro Oliveira, DDS, MS;1 Herbert Mendes Moraes, DDS;1 Luiz Eduardo Blumer
Rosa, DDS, MS, PhD2
1 Santa Casa de Misericordia de Juiz de Fora
2 Universidade Estadual Paulista - UNESP
This work was developed in Santa Casa de Misericordia de Juiz de Fora and in Universidade Estadual Paulista – UNESP
Abstract
Ameloblastomas are benign odontogenic tumors that exhibit a local malign behavior. Case report: A recurrence of an
ameloblastoma occurring after 33 years of hemimandibulectomy in a 69-year-old woman is reported. The tumor arose as
a painless mass. Clinical exam showed a lesion placed in the right third molar region. The right mandible was absent from
the bicuspid area to the condyle in radiography and computed tomography. After excision, microscopic features diagnosed
an ameloblastoma. The patient is under close follow-up and shows no recurrence or metastasis. Conclusion: Despite the
radical initial treatment, the tumor showed an uncommon behavior and recurred.
Keywords: Ameloblastoma. Odontogenic tumor, squamous. Recurrence. Mandibular neoplasms. Surgery.
Introduction
Ameloblastoma is known to be the most
significant odontogenic tumor.1 It was first described
by Broca in 1868 and named by Churchill.2 The tumor
develops from odontogenic epithelium and tooth
development cell remnants1,3 and is known to be a benign
tumor with a high tendency to recur after inadequate
treatment.1,3-6
We describe an unusual recurrence of an
ameloblastoma after 33 years of hemimandibulectomy
Case Report
A 69-year-old woman was referred to the
Oral and Maxillofacial Surgery Service at Santa Casa
de Misericórdia Hospital, Juiz de Fora, Minas Gerais,
Brazil having as her main complaint a right intra-oral
swelling with mild pain.The patient’s history showed she
underwent a right partial hemimandibulectomy without
any reconstruction 33 years earlier. Since then, no other
treatment was performed. The lesion was diagnosed,
according to the patient, as an ameloblastoma. No exam
regarding the first surgery was presented.
Physical examination showed a lack of the right
mandible and a round and large swelling in the third
molar region. The swelling was tender and painless to
Correspondence
Pietro Mainenti
Centro Médico Rio Branco - Department of Oral and Maxillofacial Surgery
Av Barão do Rio Branco 1034
36035000 Juiz de Fora Brazil
Phone: 55 32 32289999 Fax: 55 323218 9387
e-mail: [email protected]
Recurrent Ameloblastoma after 33 years of Hemimandibulectomy: Case Report
palpation.The overlying mucosa was clinically intact. An
incisional biopsy was performed showing histological
features of ameloblastoma. Conventional radiography was
done, including panoramic (Figure 1) and mandibular
posteroanterior projections. Computed tomography (CT)
was performed in axial and coronal views (Figure 2 and
Figure 3). Findings showed a lack of the right mandible
from the second premolar to the condyle. CT showed a
large round soft tissue mass with no osseous borders.
The patient showed no interest in mandibular
reconstruction, but only in tumor removal. Under general
anesthesia the patient was submitted to dissection and
excision of the lesion (Figure 4). Surgical exploration
showed a partial encapsulated tumor. The wounds were
closed with absorbable sutures. Healing was uneventful
and the patient was discharged home after 5 days.
Figure 1- Panoramic projection revealing the absence of
the right mandible
Figure 4 - Excision of the ameloblastoma
Figure 2 - Computed tomography in axial view
showing a round mass in the place of the ascending ramus
Figure 3 - Lacking of the right mandible and no image
of osseous borders (coronal view)
The specimen was immersed in 10% formalin.
Macroscopically the mass was about 4,0 x 4,0 cm (Figure
5). Histological examination showed an ameloblastoma.
There were three microscopically patterns recognized as
follicular (Figure 6), plexiform and granular cell types.
A trace of bone matrix, in only one microscopic field,
was observed.
After a year the patient is still under clinical and
radiographic follow-up and shows no recurrence or
metastasis (Figure 7).
Figure 5 - The specimen accounted for 4,0 x 4,0 cm,
approximately
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Mainenti et al.
Figure 6 - Follicular pattern showing peripheral
palisading. Hematoxylin & Eosin, 400x
Figure 7 - Chest posteroanterior projection after one
year follow-up
Discussion
Solid and multicystic ameloblastomas exhibit no
gender predilection. The age range is 30-60 years, and
in 80% of the cases the tumor occurs in the posterior
mandibular area.The lesion spreads by infiltration and may
resorb cortical plates and reach soft tissues. Histologically,
solid and multicystic ameloblastomas can be divided in
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Applied Cancer Research,Volume 28, Number 1, 2008
two forms commonly diagnosed: the follicular and the
plexiform. Other patterns, less common, are basal cell,
granular cell and acanthomatous.3
In a recent study of some selected odontogenic
tumors, the immunoexpression of calretinin, a calciumbinding protein, was detected only in ameloblastomas. It
was postulated that this protein could regulate apoptosis
and its expression might have a role in the transition of
odontogenic remnants in ameloblastomas. In addition, it
was hypothesized that ameloblastomas behavior could
be related to this protein as it was not present in other
odontogenic neoplasms.7
Ameloblastomas are expected to recur after
curettage in 50% to 90%.1,4,6 Other modalities of surgery,
as marginal resection and radical treatment with the
inclusion of adjacent soft tissues, account for 5% to 15%
of recidivation.1,6 The treatment of choice, mainly when
the lesion reaches the cortical plates and soft tissues,
is wide resection. Bone grafts can repair the defect.
Recurrence after radical surgery and reconstruction is
very rare but can develop from the stumps, soft tissues
and intraoperative contamination.5
Al-Bayaty et al.4 believed that soft tissue recidivation
of ameloblastomas was rarer than in bone grafts. They
described a case of a temporal mass in a 32-year-oldwoman. She underwent a right hemimandibulectomy
with costocondral reconstruction in 1992. After 6 years
of the first surgery a recurrence was found causing facial
deformity.The lesion was surgically exposed and dissected
from the temporalis muscle revealing microscopic features
of an ameloblastoma. The authors believed that the
recrudescence of this neoplasm was due to tumor cell
implantation in the site.
A similar case was documented by To et al.6 A 45year-old woman developed a tender temporal mass 30
years after the first treatment. Her medical history revealed
local enucleations and curettage due to recurrences of
an ameloblastoma.When she was 35 old, the patient was
submitted to a right hemimandibulectomy. The site was
reconstructed with a rib graft. 10 years after mandibular
resection a right tender temporal mass developed. By
a hemicoronal flap, the neoplasm was removed and
diagnosed as an ameloblastoma. The hypothesis was that
an infratemporal tumor seeding, during intraoral surgery,
could explain the temporal recidivation.
Although rarely expected, soft tissues recurrence
is a possibility because of tumor implantation. Our
might explain this case as a recurrence by seeding. The
neoplasm might have recurred in the same site of the
first involvement. However, we can not prove this due
to a lack of data or exams from the first surgery. Another
Recurrent Ameloblastoma after 33 years of Hemimandibulectomy: Case Report
fact that remains to be elucidated is the trace of bone
trabecula in one microscopic field. It is then difficult to
say whether the bone was remnant of the first surgery
or developed after it.
The terms metastasizing ameloblastoma and
ameloblastoma with atypia are subjected to doubts as
concerns the cases they describe. The first disease does
not differ from jaw ameloblastoma but its metastasis may
appear in other sites such as the lungs.The second one can
be defined as an ameloblastoma with malignant cytological
features8. In this case the tumor is named ameloblastic
carcinoma.3 As regards genetics, Kumamoto et al.9 stated
that aberrations in the p53 pathway (p14ARF-MDM2p53 cascade), related to cell cycle regulatory system, is
correlated to neoplastic transformation. Ameloblastomas
and metastasizing ameloblastomas showed very similar
nuclear expression of gene p53. However, ameloblastic
carcinomas present a marked increased p53 reactivity
suggesting malignant transformation of odontogenic
epithelium.
Ciment10 presented a case report of a metastatic
ameloblastoma after 29 years of a hemimandibulectomy
of a 55-year-old-man. The patient was asymptomatic.
Lung lesions were found after chest exams for cardiac
function. He suspected of granulomas despite the lack
of symptoms. A diagnostic thoracotomy identified a
metastatic malignant ameloblastoma. According to the
author, the lung is the most common site of metastases
(80%), followed by regional lymph nodes, pleura and
other organs.
As 2% to 5% of ameloblastomas do metastasize,8
we carefully submited our patient to clinical exams and
perform maxillofacial and chest radiographies. Until now,
there are no changes in the patient’s medical status.
Conclusion
The surgical approach to ameloblastomas must
include a close follow-up of the patient because of possible
recidivation at any time.We believe the case presented is
sui generis. Despite the radical initial treatment the tumor
showed an unusual behavior and recurred.
References
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