Discussion
The calcifying epithelial odontogenic tumor (CEOT) or Pindborg tumor has
been well documented in the literature since its first description. It
is a rare lesion, the reported cases didn’t exceed 4001, and it represents less than 1% of all odontogenic
tumors 3. The non-calcifying variant is very rare; it
is the least reported one 1. The radiological and
histological features of the non-calcifying epithelial odontogenic tumor
are distinguished from those of the usual calcified variant.
Consequently, there was a diagnostic challenge in the reported case and
the diagnosis of a Pindborg tumor was not suspected.
On radiographic examination, Pindborg tumor appears most commonly as a
mixed radiopaque/ radiolucent image. Both multilocular and unilocular
presentations were described. The association with an impacted tooth was
frequently found. The present case was exempt from radiopacities. This
radiolucent aspect is insufficient to diagnose a non calcifying variant
since it was described in early diagnosed immature lesions, in which
calcifications were found on histopathological examination. This
radiolucent aspect was also described in some called cystic
variant4. This radiolucent aspect may lead to the
misdiagnosis of this variant as an odontogenic cyst, like in the
reported clinical case.
The most distinctive microscopic feature of classical CEOT is the
presence of sheets of polyhedral cells, amyloid globules and Liesegang
ring calcifications in the tumor tissue5. According to
the literature, non-calcifying cases described are primarily associated
with the presence of Clear Cells and Langerhans Cells. This led authors
to the definition of variants of this tumor: the Clear Cells variant and
Langerhans Cells-rich variant 1.
The absence of calcification does not only pose a diagnostic problem,
but also has been suggested to be an indicator of poor differentiation
of the tumor. Consequently, the non-calcifying epithelial odontogenic
tumor would have more risk of recurrence and requires radical treatment
and a long-term follow-up.3
The international literature was reviewed; only 16 cases of
non-calcifying epithelial odontogenic tumor were found from 1981 to 2021
and are resumed in table 1. No sex predilection was noted (7 females/ 9
males). Age ranged from 20 to 68 years old. The present reported case
adds a female patient aged 40 years old. Ten of the cases were developed
in the maxillary bone over seven cases in the mandible, including the
present reported case. Histologically, 4 of the reported non calcifying
variants contained clear cells, 5 contained Langerhans cells, 2
contained both clear and Langerhans cells, and 5 showed neither clear
cells nor Langerhans cells like the reported clinical case. Treatment
modalities varied between enucleation and partial resection with 1cm
margins to prevent recurrence. Enucleation was preferred as a more
conservative approach in the present case since the diagnosis of
Pindborg tumor was unlikely suspected before histopathology, especially
with the absence of calcification and the sporadic similar reported
cases. Also, there were no clinical or radiological signs of
aggressivity of the lesion.
Considering the prognostic implications that present the absence of
calcifications, close follow-up appointments are mandatory to assess any
possible recurrence early. In the literature, no cases of recurrence
were reported over follow-up periods ranging from 6 months to 10 years.