Treatment of calcifying epithelial odontogenic tumor/Pindborg tumor by a conservative surgical method.

Calcifying epithelial odontogenic tumor (CEOT) also known as Pindborg tumor is a rare odontogenic epithelial neoplasm. So far nearly 200 cases have been reported in literature. We are reporting a case of CEOT in a 42-year-old male patient with painless bony swelling in the mandible. Approximately, 50% of the cases are associated with an unerupted tooth or odontome, but was not so with our case. Considering the intrabony mandibular location of the lesion and its limited size, we opted for a more conservative surgery. The clinical, radiographic and histopathologic features and the surgical treatment done are discussed with relevant references.

Calcifying epithelial odontogenic tumor (CEOT) is an odontogenic tumor arising from odontogenic epithelium.[1] It was first described in 1956 by the Late Dr. Jens J Pindborg. So CEOT is also called Pindborg tumor.[1] It is very uncommon and accounts for 0.4% to 3% of all odontogenic tumors.[23]

Approximately, 200 cases have been reported until date.[2] Histogenesis is uncertain and is believed to arise from remnants of dental lamina and stratum intermedium.[24] Here, we report a case of CEOT from our institution.

Case Report

A 42-year-old male patient reported to our institution with a chief complaint of a swelling in the right side of the mandible in the region of 43, 44 and 45. The mobile 43 and 44 were extracted in a private clinic 2 years back.

Extraorally, there was a diffuse swelling on the right side of the face with associated facial asymmetry [Figure 1]. On inspection, the diffuse extra oral swelling on the left side of face extending approximately posteriorly 4 cm from the angle of mandible, anteriorly 3 cm from the symphysis menti and inferiorly up to the inferior border of mandible. Skin over the swelling was not normal and not ulcerated. On palpation, inspector findings were confirmed. The swelling was firm in consistency and nontender. Lymph nodes were not palpable, and the temporomandibular joint was normal.

Figure 1

Incisional biopsy

Intraorally, there was an exophytic soft tissue overgrowth in the region of 43 and 44. Both these teeth were missing. On palpation, the intraoral swelling was smooth, firm, and nontender with bicortical expansion of both buccal and lingual cortical plates. The color was normal, but the shape was irregular. There was displacement of 42 and 44 with grade III mobility [Figure 2].

Figure 2

Biopsy specimen

Orthopantomograph revealed missing 43, 44 with a multilocular radiolucency, sclerotic borders and displacement of 42 and 45. Lower border of the mandible was intact. Few radioopaque spots were seen within the radiolucency [Figure 3]. Mandibular occlusal view radiographs revealed bicortical expansion of both buccal and lingual cortical plates [Figure 4]. Computed tomography scan with three-dimensional reconstruction showed an expansile soft tissue mass with areas of calcification [Figure 5].

Figure 3

Intra-oral photo

Figure 4

Histopathological slide

Figure 5

Preop CT

Incisional biopsy was done [Figure 6] and a small bit of lesional tissue was given for histopathological examination. Histopathology of the incisional biopsy specimen showed eosinophilic homogenous, acellular areas resembling amyloid and Leisegang ring type of calcifications, which was suggestive of CEOT.

Figure 6

Histopathological slide

Considering the intrabony mandibular location of the lesion and its limited size, we opted for a more conservative surgery under general anesthesia. The tumor was surgically removed completely as a mass by enucleation with removal of a thin layer of bone adjacent to the lesion, followed by curettage [Figures 7 and 8]. During surgery, the lesion proved to be primarily cystic in nature and could be easily enucleated from the surrounding bone. After enucleation, the specimen was fixed in a 4% neutral formalin solution and submitted for histopathologic examination.

Figure 7

Pre-op

Figure 8

Pre-op opg

Histopathology of the excised specimen showed islands and strands of polyhedral epithelial cells with prominent intercellular bridges. The connective tissue showed collagen fibers and eosinophilic homogenous, acellular areas resembling amyloid. Leisegang ring type of calcifications was also seen [Figure 9]. From the histopathology, a diagnosis of CEOT/Pindborg tumor was made.

Figure 9

Preop occlusogram

Healing was uneventful, except for a transitory decrease in sensitivity in the region of the right inferior alveolar nerve, which regressed progressively during the next several months. The patient was advised to come for regular follow-up to monitor the healing and prognosis. The follow-up of 1-month revealed good healing of the site and obturator had been fabricated to cover the defect [Figures 10–13]. Follow-up of 1-year revealed good healing and no recurrence.

Figure 10

Pre-op photo

Figure 13

Post-op with obturator

Post op

Discussion

Calcifying epithelial odontogenic tumor is a rare odontogenic epithelial tumor.[1] It was first described by the oral pathologist Pindborg, and hence CEOT is also called Pindborg tumor.[1] It accounts for 0.4% to 3% of all odontogenic tumors.[23]

The tumor occurs over a wide range of age the youngest being reported as 1-year and the oldest as 82 years.[1] There is no sex and race predilection.[1] A painless, slow growing swelling is the most common presenting sign.[1] About two-thirds of the cases were reported in the mandibular posterior region.[123] The present case was reported in a 42-year-old patient with a painless swelling in the mandibular premolar region. This concurs with earlier reports of clinical findings of CEOT.

The radiographic features of the tumor may be unilocular or multilocular radiolucency.[3] In our case, it was multilocular. Radiopaque flecks of calcifications are usually seen within the radiolucency.[3] This is described as “driven snow” appearance.[2] Our case also revealed similar radioopaque mass and the driven snow appearance.

Approximately 50% of the cases are associated with an unerupted tooth or odontome,[3] but was not so with our case.

Histopathologic feature usually show islands and strands of polyhedral epithelial cells with nuclear pleomorphism, prominent nucleoli and intercellular bridges.[23] One of the characteristic microscopic features of this tumor is the presence of amorphous, eosinophillic hyalinized and acellular areas resembling amyloid within or adjacent to epithelial islands.[35] These epithelial islands and amyloid-like materials were seen in our case also. The presence of amyloid can be confirmed with Congo Red Stains.[2]

Many histologic, histochemical, immunohistochemical and electron microscopic investigations were done to identify the nature of the amyloid-like material in Pindborg tumor.[56] Yamaguchi et al. and Page et al. studied the histologic, histochemical, fluorescent and ultrastructural study of CEOT and found that the eosinophilic substance was not amyloid.[6] It is now identified that this material has a unique protein that has similarity with enamel proteins and is produced by this tumor cell.[6]

Another characteristic feature of this tumor is the presence of concentric ring of basophilic calcifications called Leiesegang rings within the amyloid-like masses.[7] These were also evident in our case. These lisegang ring calcifications were thought to be a form of dystrophic calcification and cemental masses.[3] They usually fuse to form large masses of calcification.

Sometimes CEOT can occur along with adenomatoid odontogenic tumor.[8] On extremely rare occasions CEOT can show aggressive growth and features of malignancy.

Various treatment options ranging from simple enucleation to segmental resections have been proposed to treat CEOTs. Based on clinical similarities between CEOT and the solid ameloblastoma, several authors initially advocated aggressive treatment, but newer evidence that CEOT does not infiltrate into the intertrabecular bony spaces, rather supports the fact that conservative surgery is the treatment of choice of intrabony mandibular forms of CEOTs. Moreover, mandibular tumors in general tend to grow slower than their maxillary counterpart and remain usually well confined, allowing a less radical surgical approach. However, occurrence of clear cells may prove to be a sign of increased tumor aggressiveness necessitating a more radical surgical approach.[7] Nevertheless, the 11 cases of clear cell CEOT with limited follow-up information reported to date do not allow any definite conclusions in terms of biological behavior, treatment, and prognosis.[379]

The lesion was surgically excised, and reconstruction was done. The recurrence rate reported is 14–22%.[2] The patient was called for regular follow-up to monitor the prognosis. The follow-up of 1-year showed good healing of the site and no recurrence.

Conclusion

The CEOT and its clear cell variant are rare, and benign odontogenic tumors of still controversial origin can be locally aggressive in nature and have an unpredictable clinical behavior. If the clinical, radiologic, and histologic profiles of the CEOT are now well defined, other questions such as treatment strategy or incidence of recurrence are still debatable, mostly because of the small number of lesions reported in the literature and lack of long-term follow-up. We have reported a rare case of CEOT or Pindborg tumor which was diagnosed and confirmed as CEOT by incisional and excisional biopsy. It is an extremely rare odontogenic tumor and included in the differential diagnosis of all the odontogenic tumors. Treatment should be individualized for each lesion because of variations in the clinical and histologic features. The absence of recurrence seen in our patient almost 1-year after treatment is encouraging and so far brings one more argument for a conservative surgical approach for intrabony mandibular CEOTs of limited size.