Comprehensive insights into Pindborg tumor: etiology, advanced diagnostic approaches, and evidence-based management strategies – review of literature

Abstract

Pindborg tumor is a calcifying epithelial odontogenic tumor possibly arising from developmental disturbances in dental lamina remnants. It predominantly affects individuals in their third decade of life, with women also experiencing later onset. The tumor exists in two forms, namely intraosseous (central) and extraosseous (peripheral), with the former showing higher post-surgery recurrence rates of about 14%. Despite its rarity, the tumor can be misdiagnosed due to symptoms resembling dental issues and headaches, or it may even be asymptomatic. Radiologically, it presents a mix of radiolucent and radiopaque areas, sometimes unilocular or multilocular. Histopathologically, it is characterized by nests and sheets of polygonal epithelial cells with eosinophilic cytoplasm and prominent nucleoli. The presence of eosinophilic amyloid-like material and calcifications is distinctive, ranging from small concretions to larger aggregates. The exact origin of amyloids is unknown, but they are thought to derive from degraded keratin filaments. Treatment varies by tumor location, with more invasive procedures required for jaw tumors, including bone resection, due to their aggressive growth and invasion of the surrounding tissues. Accurate, individualized treatment is crucial for patient outcomes, particularly in cases where the tumor’s calcification is absent, indicating a severe impact on health. Our study included a case report of a 12-year-old patient who presented to the dental clinic complaining of sporadic pain in the area of the lower right front teeth. During a clinical examination of the area, we noticed a deformation of the alveolar bone, with a depressed mucosa. We followed the chronological steps of radiological examination, lesion excision, and histopathological examination to obtain a definitive diagnosis.

Introduction

Pindborg tumor was first described in 1955 by the pathologist Jens Jörgen Pindborg and represents a calcifying epithelial odontogenic tumor (CEOT) [1, 2]. There is disagreement on the precise etiopathogenesis and origin of CEOT, however various potential causes have been proposed. Pindborg hypothesized that CEOTs might originate from cells of the diminished enamel epithelium related to the enamel organ. According to some studies, CEOTs may originate from cells that resemble the stratum intermedium of the odontogenic apparatus [3, 4]. A possible etiological cause of this tumor is represented by developmental disturbances induced by dental lamina remnants [1, 2, 5, 6]. The mandible, particularly the area around the posterior molars, appears to be the favored location for occurrence [7].

Aim

The aim of our study was to highlight the tissue, clinical and radiological changes induced by Pindborg tumor. Also, we proposed to present the etiopathogenesis of this tumor and treatment alternatives in dental medicine. For the literature study, we accessed educational medical platforms such as PubMed, Web of Science, Scopus, and Google Scholar using the following keywords: ‘Pindborg tumor’, ‘CEOT, ‘CEOT histopathology’, ‘radiological aspects of CEOT’, ‘CEOT epidemiology’. Both review studies and case presentations were accessed.

At the same time, we present a clinical case from our own collection for a better understanding of the data in the specialized literature.

Etiology

A possible etiology of CEOT is the presence of supernumerary teeth [8]. In 2022, Morais et al. reported a case of Pindborg tumor associated with the presence of supernumerary teeth in the posterior region of the maxilla [8].

Epidemiology

The incidence of this tumor lesion is varied, and it can affect all age groups, but it predominantly occurs in subjects of the third age group [2, 9]. Our study captured a rare situation, with the patient being a 12-year-old child. Both women and men are affected by this tumor, but in the case of women, a later onset can be observed [2]. About 350 CEOT cases have been documented in the literature until 2022. In all 350 cases, no individual younger than eight years old has been affected [10]. The prevalence is three times higher in the molar region compared to the premolar region [5], with a reasonably uniform distribution in the remaining jaw sites [11]. This form of cancer causes adjacent teeth to migrate, which is usually the initial clinical sign [1, 5, 12]. CEOT typically occurs in the molar–premolar area. Bouckaert et al. reported a case which originated in the anterior maxilla or maxillary sinus wall and spread to the ethmoid sinus over time, causing the erosion of the cribriform plates in the frontal area. Despite significant orbital and cerebral involvement, there was little evidence of palatal growth. CEOT occurring in the maxillary sinus is very unusual, and in the literature, there are few examples of CEOT that may have originated in the maxillary sinus wall [13].

In this study, despite the tumor spreading, there is no proof of tooth loosening or resorption, which is therefore consistent with other authors’ findings. The underlying mucosa frequently develops as hyperemic or stays unchanged [1, 5, 12].

Classification and localization

The specialized literature describes two forms of Pindborg tumor: the intraosseous or central form, and the extraosseous or peripheral form [2, 5, 12]. Additionally, it is worth noting that, in the majority of cases, Pindborg tumor presents the phenomenon of calcification [9], but there are rare cases in which calcification is absent, and then, it is a severe lesion with a major impact on the subject’s health status [2, 5, 9, 12]. In a 2:1 ratio, the mandible is impacted more often than the maxilla. Most of the time, patients describe painless, asymptomatic swelling, and many of these occurrences are linked to an impacted or unerupted tooth. About 6% of CEOTs are extra-osseous or peripheral, despite the fact that the majority are intra-osseous. Typically, extraosseous CEOTs manifest as anterior gingival swellings. Multi-focal synchronous appearances related to CEOT have been documented in the literature very rarely [5, 14, 15].

Symptomatology and diagnosis

Pindborg tumor is quite rare in current medical practice [16] the symptoms reported by the patient can be mistaken for difficulties in dental eruption dynamics, painful sensations, or pressure [16, 17], and there are patients who report distant symptoms such as epistaxis [16], headaches, and migraines [16].

As with many asymptomatic diseases, its diagnosis is often accidental following a diagnosis for other symptomatic pathologies, such as emergency diseases or edentulism [18, 19].

Additionally, there are patients who are asymptomatic [20] or have very mild symptoms, which often results in them seeking medical attention at advanced stages of the disease.

Radiological aspects reveal a radiolucent structure alternating with areas of radiopacity [17, 21, 22, 23], appearing as either unilocular or multilocular [24].

Histopathologically, Pindborg tumor exhibits distinctive features including the arrangement of epithelial cells in nests and sheets [9, 25]. These cells typically appear polygonal with clear to eosinophilic cytoplasm and vesicular nuclei containing prominent nucleoli [26, 27]. Both a cribriform and pseudoglandular pattern can be observed [9] and while some degree of cellular variation may be present, occurrences of necrosis and atypical mitosis are infrequent. Notably, the presence of homogenous eosinophilic amyloid-like material interspersed among tumor cells is a hallmark of a calcified odontogenic epithelial tumor [27]. The exact origin of this amyloid remains uncertain, but it is hypothesized to stem from the breakdown of keratin filaments secreted by tumor epithelial cells [9, 28]. Additionally, the presence of calcification is a defining characteristic of Pindborg tumor [26, 29, 30], which can manifest in various forms ranging from small round concretions to Liesegang rings and larger aggregates, each differing in extent and shape.

Stages

It has been hypothesized that the tumor progresses through several stages, beginning with epithelial degradation and progressively generating “amyloid globules” that later combine and calcify. When the globules mineralize, their Periodic Acid–Schiff (PAS) status shifts from negative to highly positive. There is substantial debate over whether the homogeneous substance is a degradation product or actively secreted, and whether it is intracellular or extracellular intracellular in source. Some have questioned the nature of the homogenous substance, while the majority believe it is amyloid, and common stains have been used to demonstrate “amyloid” in the CEOT [11].

Page et al. [31] and Yamaguchi et al. [32] conducted histological, histochemical, ultrastructural, and fluorescent studies on CEOT and discovered that the eosinophilic material was not amyloid. It is now known that this material contains a unique protein that is analogous to enamel proteins and is by tumor cells [31, 32] but the literature claims that the existence of amyloid can be validated using Congo Red stains [5].

Chen et al. reported on the classical pattern, and histopathology of CEOT, of sheets of polyhedral epithelial cells with prominent intercellular bridges and well-defined cell boundaries; these neoplastic cells may exhibit pleomorphism, although typical mitoses are rarely seen in them. The other most distinctive results include the existence of calcified concentric Liesegang rings and compounds that resemble amyloid [11].

Based on a survey of the literature, Rydin et al. showed that there any solid evidence that clear cell CEOT behaves more aggressively than conventional CEOT [11].

The number of cases has increased since the initial descriptions, and over 362 cases have been reported to date [11].

Regarding non-calcifying CEOT, the literature data support the view that it is an aggressive form [2, 3, 5]. Indeed, non-calcifying CEOT has been shown to be extremely rare and requires a rigorous differential diagnosis based on clinical, histopathological, and radiological data [33]. The differential diagnosis is made with ossifying fibroma, pyogenic granuloma, and peripheral giant cell tumor [33]. There are data in the specialized literature supporting the position that non-calcifying CEOT is an immature lesion that predominantly affects young individuals [31, 34]. Frequently, non-calcifying CEOT is mistaken by the dentist for an odontogenic cyst, as it appears as a completely radiolucent structure with a shape similar to that of a cyst [30]. Histopathological aspects, once again, can create confusion, as there are numerous similarities between the calcified and non-calcified forms [20, 33, 35]. Some authors have considered that the presence of clear cells is associated with the aggressive, non-calcified form. However, subsequent studies have not demonstrated a causal relationship between the presence of clear cells and the aggressive variant of the tumor [30].

This tumor’s rapid proliferation rate, as shown by the Ki67 labeling index, presence of necrosis, and poor histological differentiation all point to its aggressive features. Ki67 is a nuclear protein that binds deoxyribonucleic acid (DNA) and is a non-histone. Cells produce it during the G1, S, G2, and M phases of the cell cycle, but not in quiescent (G0) cells. As a result, it is a frequently used marker to assess the rates of tumor growth [36, 37].

Another key finding is the association between the malignant transformation of CEOT and the loss of the p53 tumor suppressor gene’s transcriptional activity [36]. Known as the p53 protein, considered the “guardian of the genome”, this gene is altered most commonly in human malignancies, including oral tumors. It stops the growth of cells that have DNA damage by triggering cell cycle arrest, repairing the G1–S barrier, or triggering apoptosis. Consequently, the lack of p53 function results in a heightened vulnerability to genetic flaws, leading to malignant development and change [36, 37, 38, 39, 40]. In malignant tumor cells, p53 gene abnormalities can result in either the loss of the p53 protein or the overexpression of a non-functional mutant p53 protein [36].

Although CEOT is usually benign, its behavior changes according to the histological characteristics and site. Necrosis, a high Ki67 proliferation index, and nuclear pleomorphism have all been linked to aggressive behavior [37, 38]. Additionally, the involvement of the maxilla or maxillary sinus is linked to fast development and the invading of the orbits and skull base [39]. Intraosseous invasion is another trait associated with a greater likelihood of recurrence in comparison with extraosseous tumor [39, 40]. Contrary to this, the existence of calcification and amyloid-like material indicated increased differentiation and led to a lower probability of recurrence. Malignant growth and metastatic dissemination are exceedingly rare [39].

Differential diagnosis

In terms of differential diagnosis, the peripheral CEOT may mimic clinically or histologically multiple different lesions, including peripheral odontogenic tumors, clear cell odontogenic carcinoma with dentinoid, odontogenic carcinoma with dentinoid minor salivary gland tumors, reactive hyperplasia, tumor metastasis, and acute gingival inflammatory conditions [41]. One potential differential diagnosis of CEOT is adenomatoid odontogenic tumor, which is commonly observed in young people with a female predilection and primarily affects the maxilla. Radiological findings can be distinguished from CEOT when they contain radiopaque particles (snowflake opacities). The histological hallmarks are a thick capsule with solid cancer nests, a reticular design with duct-like organization, and polygonal cells having pale to transparent cytoplasm. Spindled and columnar cells are also present in adenomatoid odontogenic tumor.

In addition, radiologically, CEOT is radiolucent with varying calcification and might have a single or multiple cystic appearance. These findings are not particular and could be an ameloblastoma, a dentigerous cyst, or another odontogenic tumor [38, 42, 43]. Ameloblastoma, a prevalent odontogenic tumor more commonly found in young individuals, shares clinical and radiological features with CEOT, albeit with a distinct form. The traditional ameloblastoma exhibits follicular or plexiform patterns comprising patches of squamous epithelial cells having palisading basal cells and reverse epithelial polarity, surrounded by thick stroma [25].

The clinical aspects of CEOT, which include size, anatomic site, patient’s medical state, and reconstructive approaches, have a significant effect on the extent of the designed surgical resection [44, 45].

Due to the clinical resemblance between CEOT and solid ameloblastoma, numerous investigators initially suggested aggressive treatment; however, more recent data showing that CEOT does not spread into the intertrabecular bony spaces encourage the view that conservative surgery is the preferrable treatment for intrabony mandibular CEOTs. Furthermore, mandibular tumors grow at a slower rate than maxillary tumors and are typically well circumscribed, allowing for a less radical surgical strategy. However, the presence of clear cells may indicate increased tumor aggressive behavior, demanding a more extreme surgical approach [46]. Nonetheless, the 11 cases of clear cell CEOT published to date with little follow-up information do not allow for definitive conclusions on biological behavior, therapy, or prognosis [5, 46, 47].

Other authors suggest that, due to the tumor’s extraordinarily slow growth rate, at least five years (and conceivably up to 10 years) of follow-up is required [40].

Recurrence rate

The post-surgery recurrence rate is low, approximately 14% [1, 2, 5, 12], being more frequent in the case of the intraosseous form [2]. While clear cell CEOT has the potential for recurrence, studies suggest that soft tissue types are less dangerous neoplasias due to their modest size (0.5 to 2 cm), the preservation of osseous tissue, and the lack of relapse after removal [30]. Only one case documented by Shetty et al. (2014) demonstrated atypical manifestations of peripheral CEOT with large diameters and calcifications, which were treated with maxillectomy [20]. Despite these features in the current case and elsewhere, there are limited cases with signs of relapse.

Therapeutic approach

It is extremely important for each patient to receive a correct and individualized treatment plan [27]. The therapeutic approach for the tumor varies depending on its location [23]. When the tumor is located in the jaw, an invasive treatment is required that goes beyond merely removing the tumor [23]. It also involves the resection of a portion of the jawbone due to the tumor’s tendency to grow rapidly and invade surrounding structures [23, 48]. In the case of a Pindborg tumor located in the mandible, in most situations, it is sufficient to remove the lesion along with a margin of surrounding normal tissue [23]. CEOT is often treated via surgical enucleation, but the curative method varies depending on the patient [7, 49]. Curettage or a margin of safety with clinically healthy bone removal is indicated, mostly for mandibular lesions [7, 49, 50]. Although the tumor is locally invasive, in certain situations, a conservative treatment could be performed because the tumor was easily removed, and the patients were young. Due to the rarity of this tumor, a minimum follow-up period of five years is advised [7, 50]. The recurrence rate recorded is less than 15%, which is primarily related to unsuitable management [51]. An exceptionally rare carcinomatous change with regional involvement of lymph nodes has been documented in elderly people [42].

Case presentation

A 12-year-old patient came to the office complaining of sporadic pain in the area of the lower right front teeth. During a clinical examination of this area, we noticed a deformation of the alveolar bone, with a depressed mucosa. On palpation, the patient complained of pain there was no mobility of the adjacent teeth, only some displacement, and the vitality tests were positive.

We noticed during the radiological examination an aspect of the tumor lesion: radiotransparency with isolated outbreaks of radiopacity (calcification) between teeth 4.2 and 4.3. No areas of resorption were observed on the external surface of the roots of the neighboring teeth. The decision was made to perform an excision of the tumor formation (Figure 1A, 1B). Radiological appearance: the lesion was unilocular with well-defined margins, in contact with the roots of adjacent teeth, and presented calcifications that produced irregular radiopacities.

Figure 1.

Radiological aspect of the tumor lesion: (A and B) Radiotransparency with isolated outbreaks of radiopacity (calcification) between teeth 4.2 and 4.3.

The tumor lesion was excised under local anesthesia. Post-excision, it was observed that the tumor had a round/oval shape and a significant size of 1.5 cm, which led to the deformation of the cortical bone, causing it to bulge outward. Under loco-regional anesthesia, an “L” shaped incision was made, and an intrasulcular flap was elevated, exposing the vestibular cortical bone bulging between teeth 4.2 and 4.3, which was eroded over an area of approximately 0.5 cm2, revealing the gray-colored tumor membrane at this level. Using a piezotome, the access was widened, and the vestibular tumor membrane was completely exposed. The cystic membrane was easily extirpated via facile detachment from the bony walls, with the roots of the adjacent teeth not being exposed in the remaining bony defect; additional curettage was not necessary. The tumor was well-demarcated and was entirely extirpated with its contents, without the need for decompression. The membrane was sufficiently resilient to avoid rupture during detachment from the bony walls and appeared gray in color. The remaining bone tissue appeared normal, the bony margins were smoothened, the wound was cleansed with saline solution, and the flap was interrupted suture.

The tumor excision was performed in the dental clinic under local anesthesia after a clinical and imagistic evaluation.

The sample obtained after surgery was rinsed in phosphate-buffered saline (PBS), and the fragments were fixed in 10% neutral buffered formalin for 24 hours at room temperature and processed for paraffin embedding. Sections of 3–4 μm were mounted onto glass slides and stained with Hematoxylin–Eosin (HE) and Congo Red in order to assess the quality of the tissue and its histological features. To detect the amyloid structure, we used the Congo Red staining Kit (ab150663) which comprises Congo Red solution and Hematoxylin.

Immunohistochemistry

Serial sections of 3–4 μm were dewaxed and rehydrated. For antigen retrieval, we incubated the sections in a microwave using the appropriate buffer. Endogenous peroxidase activity was blocked by incubation with 3% hydrogen peroxide (H2O2) in methanol. Following a blocking step to prevent nonspecific binding, the sections were incubated overnight at 4°C with one of the primary antibodies listed in Table 1. Next, the sections were washed with PBS at pH 7.4–7.6 and processed for immune signal amplification using the Dako Envision™+ Dual Link System–Horseradish Peroxidase (HRP) (Dako, Carpinteria, USA), following the manufacturer’s instructions. The sections were then counterstained with Mayer’s Hematoxylin.

Table 1.

Antibodies used in our study

Antibody	Manufacturer	Dilution	Clone	Reaction/Positivity
CK AE1–AE3	Leica	1:100	Cocktail AE1–AE3, 20:1	Membrane
Ki67	Dako	1:75	MIB-1	Nuclear
α-SMA	Cell Marque	1:500	1A4 mouse monoclonal antibody	Cytoplasmic
S100	Dako	1:400	Polyclonal rabbit GA50461-2	Nuclear, cytoplasmic
CK19	Leica Biosystems	1:50	b170	Membrane
Vimentin	Cell Marque	1:100	Mouse monoclonal V9	Cytoplasmic

CK: Cytokeratin; α-SMA: Alpha-smooth muscle actin

For each antibody, a negative control was performed by replacing the primary antibody with 10 mM PBS at pH 7.4–7.6. Color development was achieved using 3,3’-Diaminobenzidine (DAB) tetrahydrochloride (Sigma-Aldrich) and H2O2 (Merck), with Mayer’s Hematoxylin used for nuclear counterstaining. Finally, the samples were cover-slipped with DPX (Sigma-Aldrich).

Cytoplasmic, membrane, and nuclear staining were deemed positive. In the immunohistochemical (IHC) analysis of neoplastic cells, the presence (+) or absence (-) of immunostaining was assessed, and the intensity of immunopositivity was categorized as strong (++) or weak (+). The role of each antibody was described in Table 2. The distribution pattern (focal or diffuse) and the location of stained cells within the tumor structure were also evaluated. All specimens were examined and photographed using a Nikon Eclipse 600 microscope (Nikon, Japan). We chose these markers for the following reasons:

Table 2.

The role of histological staining and markers used in our study

No.	Staining / Immunomarker	Reactivity
1.	Hematoxylin–Eosin	An overview of the tissue’s components
2.	Congo Red	Highlights the amyloid structure
3.	CK AE1–AE3	Differentiate epithelial tumors from non-epithelial tumors
4.	Ki67	Marks cell proliferation
5.	CK19	Identifies dysplasias in the oral epithelium
6.	S100	Marks the cells originating in the neural crest
7.	α-SMA	Marks smooth muscle actin
8.	Vimentin	A suggestive marker for a mesenchymal origin of a tumor lesion

CK: Cytokeratin; α-SMA: Alpha-smooth muscle actin

▪ Anti-alpha-smooth muscle actin (α-SMA) antibody marks SMA, in our case marking the mesenchymal cells of the dental papilla, but also the cells of the ameloblast layer.

▪ Cytokeratins (CKs) AE1 and AE3 are markers that help differentiate epithelial tumors from non-epithelial tumors. In the case of our reaction, positivity for this marker was observed at the level of columnar epithelium.

The intervention did not result in any postoperative complications, and it benefited from a minimally invasive treatment that did not affect the mandible bone or the teeth adjacent to the tumor (Figure 2A, 2B).

Figure 2.

Patient, age 12 years: (A) Intraoperative aspect during surgical excision of the tumor; (B) Aspect of the post-excisional lesion: round/oval shape, size 1.5 cm

The positive diagnosis was made with the help of the histopathological and IHC examination, through which we wanted to observe, in a targeted manner, what changes the cells, vessels, and nerves had undergone (Figure 3; Figure 4A, 4B; Figure 5A, 5B, 5C, 5D; Figure 6A, 6B).

Figure 3.

Radiological aspect one year after the surgical intervention: spontaneous healing of the bone is observed, and the insertion axis of the adjacent teeth has returned to the anatomical position. L: Left; R: Right.

Figure 4.

(A and B) The structural aspect of the mandibular bone and adjacent teeth one year after surgery

Figure 5.

Microscopic aspects: (A) Overview image of the tumor: only the portion consisting of soft, non-mineralized tissue is visible; (B) Overview aspect of a tumor area; (C) Detailed aspect; (D) Overview image of the tumor reveals folds of epithelial tissue folding into a mesenchymal connective tissue. Hematoxylin–Eosin (HE) staining: (A and D) ×45; (B and C) ×100

Figure 6.

(A) CK AE1–AE3 positivity is noted in the columnar epithelium, which is around the layer of differentiated ameloblasts; above is the intermediate epithelium, which is also positive; the two epithelia are part of the enamel organ, of ectodermal origin; that is why CK positivity is observed; underlying this is the dental papilla, with negative undifferentiated mesenchymal cells (does not contain CK), lacking vascularity; (B) α-SMA negativity is observed both in the cells of the dental papilla (mesenchymal cells) and in the cells of the ameloblast layer. Anti-CK AE1–AE3 antibody immunomarking: (A) ×10. Anti-α-SMA antibody immunomarking: (B) ×4. α-SMA: Alpha-smooth muscle actin; CK: Cytokeratin

▪ CK19 is a marker used to identify dysplasias in the oral epithelium. In our study, we observed positivity in the ameloblastic epithelium (Figure 7A).

Figure 7.

(A) CK19 positive in the ameloblastic epithelium, but negative in the intermediate epithelium; (B) VIM is positive in the mesenchymal cells of the dental papilla; additionally, there are a few small-caliber blood vessels present, with endothelial cells also positive for VIM; (C) S100 negative in the stromal cells, but it appears slightly positive in the columnar epithelium; (D) Several Ki67-positive nuclei in the tumor stroma (dental papilla), more in the peripheral layer (pre-odontoblasts and mesenchymal cells); in the columnar epithelium, nuclei undergoing division are more frequent. Anti-CK19 antibody immunomarking: (A) ×100. Anti-VIM antibody immunomarking: (B) ×100. Anti-S100 antibody immunomarking: (C) ×40. Anti-Ki67 antibody immunomarking: (D) ×100. CK19: Cytokeratin 19; VIM: Vimentin

▪ Vimentin is a suggestive marker for a mesenchymal origin of a tumor lesion. In our study, the IHC reaction with vimentin targeted the mesenchymal cells of the dental papilla and the ectomesenchyme of the neural crests (Figure 7B).

▪ S100 protein marks the cells originating in the neural crest, in our case the cells from the chorion level, but also the cells from the cylindrical epithelium (Figure 7C).

▪ Ki67 marker is used to mark cell proliferation. Study showed positivity for the Ki67 marker at the level of the nuclei of dividing cells in the tumor stroma (Figure 7D).

The formation comprises an epithelial-like component, with a simple columnar epithelium (similar to the ameloblastic epithelium of the enamel organ), covering a mesenchymal structure of a myxoid aspect rich in cells and ground substance. In some areas at the periphery of this stromal structure, material, amorphous and unstructured, possibly osteodentin or rapidly deposited tertiary dentin, incorporating cells within its mass, resembling bone tissue containing osteocytes. Columnar cells with a secretory appearance are distributed in a pseudostratified manner, forming villous formations. These could be odontoblasts or odontoblast-like cells that have synthesized eosinophilic material. Differentiations of the surface cells are noticeable, situated beneath the ameloblastic epithelium, which may represent mesenchymal cells undergoing differentiation towards odontoblasts. Amyloid was also identified in the tumor using Congo Red staining (Figure 8).

Figure 8.

Congo Red staining (×400) highlights the presence of amyloid (red color). Inflammatory cells can be seen around the image

Postoperatively, sensitivity tests were performed on the teeth located near the tumor formation, and it was observed that they retained their vitality. In addition, no postoperative tooth mobility was recorded.

The postoperative course was favorable, with uncomplicated healing facilitated by a four-day regimen of systemic anti-inflammatory treatment. There was no need for pre- or post-operative antibiotic therapy and sutures were removed on the seventh day. At one year postoperatively, complete bone regeneration was observed, with teeth 4.2 and 4.3 returning to their anatomical positions, without any signs of local recurrence.

Conclusions

Pindborg tumor requires a rigorous interdisciplinary approach, combining clinical and paraclinical examinations to establish a complete and accurate diagnosis. Histopathological examination is essential for a definitive diagnosis. The varied morphology of the tumor lesion, as well as its incidence, symptomatology, and evolutionary tendency, create diagnostic challenges. People in their third decade of life are primarily affected, with women reporting a later onset, and this tumor can also affect children. There are two forms of Pindborg tumor: the calcified form, which is the most common, and the non-calcified form, the latter being an aggressive lesion with a tendency to invade tissues. Various surgical techniques have been proposed, and the course of therapy depends on many variables, including the location and size of the tumor as well as the patient’s overall health and the operator’s competence. Metastasis and malignant transformation are uncommon.

Conflict of interests

The authors declare no conflict of interests. All authors have read and agreed to the published version of the manuscript.