AMELOBLASTOMA
CT features in various presentations
Abstract ID Number 1119
INTRODUCTION
• Ameloblastoma (previously called adamantinoma) is the most
common epithelial odontogenic tumor.
• usually occurs in 2nd to 3rd decade age group [except unicystic
variant which is more common in adolescents].
• no gender predilection.
• locally aggressive, infiltrative tumor which can rarely turn
malignant or metastasize.
• It arises from the enamel-forming cells from odontogenic
epithelium that failed to regress during embryogenesis.
• The ramus and posterior body of mandible is most common
location (80%), only 20% of lesions found in the maxilla.
• WHO classifies benign ameloblastomas into
1.
2.
3.
4.
Solid/multicystic
Extra-osseous/peripheral
Desmoplastic
Unicystic
MATERIALS & METHODS:
• CT done using 64-MDCT (GE Lightspeed) scanner for 8
cases with swelling in lower jaw/ neighboring area of
face selected from this year. Contrast administered to the
cases with soft- tissue density swelling.
• 5 were painless, 3 painful.
• 3 cases had h/o enucleation; 1 with h/o right
maxillectomy & mandibulectomy - came with
recurrence.
• They underwent segmental resection/ mandibulectomy
and all were histopathologically proven as
ameloblastomas [except one case -ameloblastic
carcinoma].
CASE 1: 25-year old female came with painless, progressive
swelling over left angle of mouth since 1 year.
•well-defined,
expansile cystic
lesion without any
obvious soft tissue
component.
•in the body and
ramus of left
hemimandible, with
areas of cortical
break.
•Resorption of first
molar root seen
•unicystic
ameloblastoma on
biopsy
CASE 2: A 19-year old male presented with a
mass in the left lower jaw for 25days.
• welldefined,
biloculated,
heterogeneously
enhancing soft tissue
expansile lytic lesion
• In the ramus, body and
angle on the left side of
mandible.
• left side third molar
tooth within.
• cortical defects.
• biopsy – solid
multicystic
ameloblastoma.
CASE 3: A 42-year old female came with
painful, left lower jaw swelling for 15days.
• well-defined ,unilocular ,expansile lytic
lesion.
• from left side of body of mandible
crossing midline to symphysis menti
• few dense foci within
• focal defect only in outer cortex
• unicystic ameloblastoma on HPE.
CASE 4: 22-year old male h/o painless, slowly growing,
swelling in left lower jaw since 8 years ago, underwent
cyst enucleation 5 years back, now came with recurred
swelling in the same site.
• well-defined,
unilocular
expansile lytic
lesion
• in the body and
angle on left side
of the mandible
• multiple cortical
breaks.
• Biopsy -recurrent
unicystic
ameloblastoma.
CASE 5: A 55 year old male with swelling in left lower jaw for 4
years, h/o cyst enucleation [HPE –ameloblastoma], now with
recurrent swelling in same site since 2 months.
•
•
•
•
•
heterogeneously enhancing
multilocular lytic expansile
lesion
from body to angle of
mandible on left side
cortical break,
few dense foci
HPE- recurrent solid,
multicystic
ameloblastoma
CASE 6: 70-year old male with h/o right maxillectomy 7
years ago, mandibulectomy & neck dissection 3 years
ago (histologically ameloblastoma) came now with
swelling in the region of right maxilla, pain in right side
of face and eyelid edema since 1 month.
• heterogeneously
enhancing soft
tissue lesion from
the region of right
maxilla
• Intracranial
extension into
temporal lobe,
aggressively
eroding adjacent
bones.
• Intraorbital
extensionproptosis.
• HPE- recurrent
solid
ameloblastoma.
CASE 7: 60-year old male with h/o swelling in the left side of
face 4 years, underwent cyst enucleation (HPE-ameloblastoma),
now with recurrent swelling in same site since 1 year.
• Heterogeneously enhancing soft-tissue,
expansile lytic lesion
• in the ramus of left mandible
• with cortical destruction,
• with a cystic component within.
• HPE-recurrent solid multicystic
ameloblastoma
CASE 8: 55-year old male with painful, progressive
swelling on right side of face since 1 year.
•
•
•
•
•
•
welldefined, multiloculated
heterogeneously
enhancing soft-tissue
lesion with few nonenhancing areas within
(necrosis/ cystic areas)
from right side of mandible
(beak sign positive)
cortical destruction,
extending into right
infratemporal fossa.
no evidence of metastasis.
HPE - ameloblastic
carcinoma.
RESULTS
Type of Ameloblastoma
among 8 cases
side of mandible /
maxilla affected
unicystic [3]
right [2]
solid/multicystic
[4]
malignant [1]
left [6]
•Of the total 8 cases, 4 cases were older than 50 years of age when
initially diagnosed which is rarer.
• Among the 5 solid lesions, all showed heterogeneous contrast
enhancement.
Bony septae within and root
resorption of teeth are
commonly associated features
with ameloblastomas but among
the 8 cases, these were seen
only in case 1.
Unicystic ameloblastoma is a less
encountered variant, more in
<30yrs age, almost exclusively
asymptomatic & in the posterior
mandible.
Case 3 was unusual in older age
[42 yrs] painful, unicystic
ameloblastoma, crossing the
midline and occupying the
symphysis menti
Case 6 was a highly
aggressive recurrent
ameloblastoma with illdefined margins,
extending intracranially
and intraorbitally with
extensive bone
destruction.
Cortical defects - both inner
and outer cortex were seen in
all cases except case 3 with
focal outer cortical defect.
Case 8 was a very rare primary
ameloblastic carcinoma in the
right hemimandible with
extension to the right
infratemporal fossa.
CONCLUSION
• CT is an excellent imaging modality to characterize the
lesion and know the extent of tumor invasion.
• Histopathology is mandatory to confirm the diagnosis.
• Close differentials are dentigerous cyst, odontogenic
keratocyst, odontogenic myxoma and aneurysmal bone
cyst.
• Treatment of ameloblastoma depends on extent of
infiltration. A well-contained lesion is excised with wide
margins; en bloc resection is done for an extensive
lesion.
• Follow-up with CT is important as ameloblastomas have
high rate of recurrence.
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1.
2.
3.
4.
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