The amyloid deposit in calcifying epithelial odontogenic tumor is immunoreactive for cytokeratins

Conventional Ameloblastoma. A Case Report with Microarray and Bioinformatic Analysis

Ameloblastoma is a rare benign epithelial odontogenic neoplasm, but with great clinical implications, as despite its benignity and slow growth, most cases are locally aggressive with a significant recurrence rate. Histological, cellular, or molecular analyses of its pathogenesis have confirmed the complexity of this neoplasm. We present the case of a 20-year-old patient with a suggestive clinical and radiographic diagnosis of ameloblastoma. An incisional biopsy was obtained confirming the diagnosis of conventional ameloblastoma. Left hemimandibulectomy and plate reconstruction were performed. Histopathological analysis of the surgical specimen confirmed the conventional ameloblastoma with a plexiform pattern and significant areas of cystic degeneration and amyloid-like-like deposits. Additionally, a microarray was carried out with bioinformatic analysis for the enrichment, protein interaction, and determination of eight hub genes (CRP, BCHE, APP, AKT1, AGT, ACTC1, ADAM10, and APOA2) related to their pathogenesis.

Hyalinizing clear cell carcinoma of the soft palate: a review of literature review

Hyalinizing clear cell carcinoma (HCCC), also known as clear cell carcinoma, not otherwise specified [CCC, (NOS)], is a rare minor salivary gland tumor characterized by proliferation of clear cells, organized in trabecular cords, or solid nests within loose to densely hyalinized stroma. It is considered a diagnosis of exclusion by the World Health Organization (WHO) because other salivary tumors may also have a clear cell component. Hence, there is a wide differential diagnosis. EWSR1-ATF1 gene rearrangements are fairly specific for this tumor, however, one of the recent studies have described its presence in clear cell odontogenic carcinoma (CCOC) one of its histologic mimickers. EWSR1 and CREM fusions have recently been described in these tumors but its importance is still not well described. Here we present a case of a 33-year-old woman who presented with a recurrent lesion of the soft palate. Her initial lesion was resected and diagnosed as low-grade myoepithelial tumor. Surgical margins at the time of initial resection were positive and the re-excision was recommended but the patient did not undergo surgery. Two years later, local recurrence at the same site was found and an excision was performed yielding negative margins. Histopathologic examination revealed features consistent with hyalinizing clear cell carcinoma. The patient remains disease free 1 year after the re-excision. The pathology, clinical characteristics, differential diagnosis and treatment of hyalinizing clear cell carcinoma are reviewed.

Calcifying epithelial odontogenic tumors (Pindborg tumor) of maxilla in pediatric patients

The calcifying epithelial odontogenic tumor (CEOT) was first described by Pindborg as a distinct entity in 1955. Odontogenic tumors are derived from epithelial, ectomesenchymal, and/or mesenchymal elements that are or have been a part of the tooth-forming apparatus. Of all the odontogenic tumors, CEOT accounts for 1% of the cases. There is no sex predilection, with a 2:1 predilection for the mandible, mostly in the premolar/molar region. The CEOT typically presents clinically as an intraosseous, expansile, and painless mass that exhibits slow growth. It is often locally invasive. Most often, it is associated with an impacted tooth, is asymptomatic, and requires biopsy for diagnosis. Although most of these cases are primarily intraosseous, an extraosseous tumor is also known to occur, first observed by Pindborg in 1966. The lesions were surgically enucleated, and histopathological examination confirmed CEOT. The purpose of this article is to describe one additional case of both variants of CEOT.

Pindborg tumor: Pathology with special stains

Odontogenic tumors constitute a wide spectrum of lesions ranging from malignant and benign neoplasms to dental hamartomas, all derived from the epithelial and ectomesenchymal remnants of the tooth forming apparatus. Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, benign epithelial odontogenic tumor first described by Pindborg in 1956. It is a universally accepted eponym for this neoplasm. Pindborg tumor or CEOT is a locally aggressive neoplasm that accounts for 1% of the total odontogenic tumors, with recurrence in 14% of cases. The etiology of this tumor remains an enigma to the clinician. Pindborg suggested that the tumor arises from the remnants of reduced enamel epithelium of an unerupted tooth. Recent studies in literature report that the tumor arises from stratum intermedium. We report a case of Pindborg tumor in a 22-year-old male patient in the left mandibular posterior region. Radiographically, a well-defined radiolucency was associated with unerupted mandibular second molar which was displaced to the inferior border of the mandible. Along with routine haematoxylin and eosin stains, this case reports histopathological findings using Congo red stain and modified Gallegos stain.

Pigmented Pindborg tumor of the maxilla: A case report

The calcifying epithelial odontogenic tumor (CEOT), also known as the Pindborg tumor, is a benign locally invasive neoplasm. Common variants of CEOT include noncalcifying, Langerhans cell, bone and cementum forming and clear cell, which have a prognostic significance. Pigmented variants are known to occur in other odontogenic tumors. However, a definitive pigmented variant of CEOT has not been reported in literature so far. Here, we report the first case of pigmented Pindborg tumor arising from the maxilla in a young female. The pigment was demonstrated as melanin by staining and confirmed by immunohistochemistry. The pigmented variant of CEOT did not recur within 18 months postsurgery. Our report indicates that it is essential to recognize the pigmented variant. We discuss the common variants of CEOT and potential histogenesis of the pigmented variant. Further studies are required to reveal the histogenesis of melanocytes and their pathological significance in the odontogenic tumors.

Intraosseous calcifying epithelial odontogenic tumor in a case with multiple myeloma

Calcifying epithelial odontogenic tumor (CEOT), also known as Pindborg tumor, is a rare benign odontogenic tumor of locally aggressive behavior. It is more common in the posterior part of the mandible of adults, typically in the fourth to fifth decades. Its origin as well as its true malignant potential is not clearly known. It usually starts as a painless swelling and is often concurrent with an impacted tooth. A case of CEOT in a 55-year-old man with multiple myeloma is presented. Clinical, radiological, and pathologic findings are discussed.

Calcifying epithelial odontogenic tumor in anterior maxilla associated with a supernumerary tooth: a case report

Odontogenic tumors are derived from epithelial, ectomesenchymal and/or mesenchymal elements that are or have been a part of the tooth-forming apparatus. Of all the odontogenic tumors, calcifying epithelial odontogenic tumor accounts for 1% of the cases. Approximately 200 cases have been reported to date. There is no sex predilection, with a 2:1 predilection for the mandible, mostly in the premolar/molar region. It is often locally invasive. Most often, it is associated with an impacted tooth, is asymptomatic and requires biopsy for diagnosis. Presented here is a rare case of an intraosseous calcifying epithelial odontogenic tumor surrounding a supernumerary tooth. Furthermore, the occurrence of this tumor in the anterior maxilla (an uncommon site) in a pediatric patient makes it rarer. Although the present case was asymptomatic, root resorption and displacement of adjacent teeth necessitated its surgical removal. The lesion was surgically enucleated and histopathological examination confirmed calcifying epithelial odontogenic tumor, showing abundant calcifications in the form of Liesegang rings.

Calcifying epithelial odontogenic tumor (Pindborg tumor) without calcification: A rare entity

The calcifying epithelial odontogenic tumor is a rare benign odontogenic tumor that was first described by Pindborg in 1955. It accounts for less than 1% of all odontogenic neoplasms. The tumor is characterized histologically by the presence of polygonal epithelial cells, calcification, and eosinophilic deposits resembling amyloid. Noncalcifying Pindborg tumor is very rare and only three cases have been documented in the English language literature so far. We present an additional case of noncalcifying Pindborg tumor and review the previously reported cases. Because noncalcifying Pindborg tumor is believed to be an aggressive variant, a definitive resection of the tumor with tumor-free surgical margins and long-term follow-up is recommended.

Calcifying epithelial odontogenic tumor (Pindborg tumor)

The calcifying epithelial odontogenic tumor is a benign epithelial tumor with characteristic clinical and histopathologic features. These features are discussed with a typical case presentation along with emphasis on newer variants and management strategies.

Oral Masses in Two Cats

Incisional biopsies from the oral cavity of 2 adult cats were submitted for histological investigation. Cat No. 1 showed a solitary well-circumscribed neoplasm in the left mandible. Cat No. 2 demonstrated a diffusely infiltrating neoplasm in the left maxilla. Both tumors consisted of medium-size epithelial cells embedded in a fibrovascular stroma. The mitotic index was 0 to 1 mitosis per high-power field. The epithelial cells showed an irregular arrangement forming nests or streams in cat No. 1, whereas a palisading growth was noted in cat No. 2. Both tumors, especially that of cat No. 1, showed multifocal accumulations of amyloid as confirmed by Congo red staining and a distinct green birefringence under polarized light, which lacked cytokeratin immunoreactivity as well as and AL and AA amyloid immunoreactivity. In addition, the amyloid in cat No. 2 was positive for the odontogenic ameloblast-associated protein, formerly termed APin. In sum, both cats suffered from an amyloid-producing odontogenic tumor, but their tumors varied with respect to morphology and type of amyloid produced.

Biochemical and immunohistochemical characterization of the amyloid in canine amyloid-producing odontogenic tumor

The amyloid of canine amyloid-producing odontogenic tumor (APOT) was evaluated biochemically and immunohistochemically. The N-terminal amino-acid sequence of purified amyloid protein from a canine APOT was strikingly similar to the sequence in both rat ameloblastin and porcine sheathlin. Immunohistochemically, the amyloid in APOT from 9 dogs was strongly reactive with anti-rat ameloblastin, anti-porcine sheathlin, and anti-canine APOT amyloid and weakly reactive with anti-porcine amelogenin but negative for antibodies to cytokeratins, vimentin, desmin, alpha-smooth muscle actin, amyloid A, glial fibrillary acidic protein, or S100 protein. The neoplastic epithelial cells of APOT were focally reactive with antibodies to ameloblastin, sheathlin, amelogenin, and canine APOT amyloid. The similarity in amino-acid sequence of the amyloid protein of canine APOT to that of enamel proteins, such as ameloblastin, sheathlin, and amelogenin, and the expression of these antigens in both APOT amyloid and in the neoplastic cells suggest that the amyloid of canine APOT is derived from enamel proteins secreted by ameloblasts.

Amyloid-producing odontogenic tumor and its immunohistochemical characterization in a Shih Tzu dog

A 10-year-old, male, Shih-Tzu dog presented with swelling of the right lower jaw caused by a mass arising from the right mandibular gingiva. Radiographic examination revealed bone lysis of the right wing of the mandible. Histopathologically, the growth was characterized by indistinctly lobulated nests, islands, and strands of proliferating odontogenic and squamous epithelial cells, intermingled in close association with large numbers of irregular extracellular deposits of amyloid and amorphous calcified substance. Immunohistochemically, both epithelial components stained strongly positive for cytokeratin (AE1/AE3); the squamous epithelial cells also reacted strongly with neuron-specific enolase (NSE) and S-100 protein, whereas the odontogenic epithelial cells displayed weak immunoreactivity to NSE and partial reactivity to S-100 protein. The amyloid deposits were AE1/AE3-negative. The growth was diagnosed as an amyloid-producing odontogenic tumor.

Calcifying epithelial odontogenic tumor: an immunohistochemical case study

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic tumor. A case of CEOT in a 25-year-old female is presented here. Histologically, the case showed sheets of polyhedral epithelial cells with deep eosinophilic cytoplasm and prominent nuclei. Nuclear pleomorphism and hyperchromatism were evident. Globules of amyloid-like material among the tumor cells were prominent. Also found was a small area demonstrating a cribriform pattern. Immunohistochemical studies with antibodies against basement membrane proteins (laminins 1 and 5, collagen type IV and fibronectin), pan-cytokeratins AE1/AE3, vimentin, S-100 protein and CD 1a were performed. Tumor cells expressed laminins 1 and 5, fibronectin, cytokeratins and vimentin. The amyloid-like material was not reactive to all antibodies examined. A number of dendritic cells among sheets of tumor cells were revealed with strong staining for S-100 protein and CD 1a. These dendritic cells are likely to be Langerhans cells. Hence, immunohistochemistry is a useful method to study the variant of CEOT.

Amyloid-producing odontogenic tumour (calcifying epithelial odontogenic tumour) in the mandible of a Bengal tiger (Panthera tigris tigris)

A 13-year-old male tiger (Panthera tigris tigris) had a marked mandibular swelling noticed 12 months earlier and associated with progressive anorexia and weight loss. Radiological and post-mortem examination revealed a mass (13x15 cm) which was firm and poorly defined, with destruction of the adjacent bone tissue. Histologically, the mass was poorly demarcated, with infiltrative growth, and composed of nests, cords and islands of epithelial cells with characteristic basal cell features. Also observed were extensive squamous metaplasia, ghost cells, stellate reticulum, and fibroblastic connective tissue stroma containing inflammatory cells. A prominent feature of this tumour consisted of abundant nodular deposits of congophilic amyloid-like material with partial mineralization (Liesegang rings). Immunohistochemically, the neoplastic cells and the amyloid-like material were positive for pancytokeratin and negative for vimentin. The findings supported the diagnosis of an amyloid-producing odontogenic tumour (APOT), also known as calcifying epithelial odontogenic tumour in man and animals.

[Calcifying epithelial odontogenic tumor of the maxilla (Pindborg tumor)]

A male patient presented with an extraordinarily large calcifying epithelial odontogenic tumor (CEOT or Pindborg-tumor) that affected the maxilla. The disease became evident due to alterations in the facial aspect, in particular of the perioral region, caused by the expanding tumor. CEOT is characterised by the slowly growing mass of part of the jaws. Multilocular or extraosseous manifestations are extremely rare. Malignant transformation with metastases is rare. Radiography depicts characteristic, but not obligatory, areas of calcification inside the tumor. The surgical therapy for CEOT is complete local resection with safe margins. If tooth bearing parts of the jaws are affected, these teeth almost always have to be removed. The prognosis is excellent for overall survival. Local recurrences have rarely been reported but may be found even decades after primary treatment. Three years following surgical therapy there is no evidence of local recurrence. A long-term follow-up control is recommended.

Calcifying epithelial odontogenic (Pindborg) tumor-associated amyloid consists of a novel human protein

Calcifying epithelial odontogenic tumors (CEOTs), also known as Pindborg tumors, are characterized by the presence of squamous-cell proliferation, calcification, and, notably, amyloid deposits. On the basis of immunohistochemical analyses, the amyloidogenic component had heretofore been deemed to consist of cytokeratin-related or other molecules; however, its chemical composition had never been elucidated. We have used our microanalytic techniques to characterize the protein nature of CEOT-associated amyloid isolated from specimens obtained from 3 patients. As evidenced by the results of amino-acid sequencing and mass spectrometry, the fibrils were found to be composed of a polypeptide of approximately 46 mer. This component was identical in sequence to the N-terminal portion of a hypothetical 153-residue protein encoded by the FLJ20513 gene cloned from the human KATO III cell line. That the amyloid protein was derived from this larger molecule was demonstrated by reverse transcription-polymerase chain reaction amplification of tumor-cell RNA where a full-length FLJ20513 transcript was found. Furthermore, immunohistochemical analyses revealed that the amyloid within the CEOTs immunostained with antibodies prepared against a synthetic FLJ20513-related dodecapeptide. Our studies provide unequivocal evidence that CEOT-associated amyloid consists of a unique and previously undescribed protein that we provisionally designate APin.

Peripheral clear cell variant of calcifying epithelial odontogenic tumor: Report of a case and immunohistochemical investigation

A case of peripheral calcifying epithelial odontogenic tumor, clear cell variant, located on the right gingival maxilla of a 48-year-old woman, presenting as a 2.0-cm solitary, firm nodule was studied. Microscopically, it was composed of polyhedral and clear epithelial cells associated with amyloid-like deposition. The clear epithelial cells exhibited granules that were positive for periodic acid-Schiff, and the amyloid-like deposit stained with Congo red showed a green birefringence in the polarized light. Polyhedral and clear epithelial cells were immunopositive for AE1/AE3 and cytokeratin 14. Immunoexpression of fibronectin and types I and III collagen were different between the amyloid-like deposits and the connective tissue stroma. Tenascin surrounded epithelial cells located inside the amyloid-like deposits. Laminin and type IV collagen were immunodetectable around the strands, cords, and nests of epithelial cells. This report represents the seventh case of peripheral calcifying epithelial odontogenic tumor, clear cell variant.

Odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws

Odontogenic cysts that can be problematic because of recurrence and/or aggressive growth include odontogenic keratocyst (OKC), calcifying odontogenic cyst, and the recently described glandular odontogenic cyst. The OKC has significant growth capacity and recurrence potential and is occasionally indicative of the nevoid basal cell carcinoma syndrome. There is also an orthokeratinized variant, the orthokeratinized odontogenic cyst, which is less aggressive and is not syndrome associated. Ghost cell keratinization, which typifies the calcifying odontogenic cyst, can be seen in solid lesions that have now been designated odontogenic ghost cell tumor. The glandular odontogenic cyst contains mucous cells and ductlike structures that may mimic central mucoepidermoid carcinoma. Several odontogenic tumors may provide diagnostic challenges, particularly the cystic ameloblastoma. Identification of this frequently underdiagnosed cystic tumor often comes after one or more recurrences and a destructive course. Other difficult lesions include malignant ameloblastomas, calcifying epithelial odontogenic tumor, squamous odontogenic tumor, and clear-cell odontogenic tumor. Histologic identification of myxofibrous lesions of the jaws (odontogenic myxoma, odontogenic fibroma, desmoplastic fibroma) is necessary to avoid the diagnostic pitfall of overdiagnosis of similar-appearing follicular sacs and dental pulps. Fibroosseous lesions of the jaws show considerable microscopic overlap and include fibrous dysplasia, ossifying fibroma, periapical cementoosseous dysplasia, and low-grade chronic osteomyelitis. The term fibrous dysplasia is probably overused in general practice and should be reserved for the rare lesion that presents as a large, expansile, diffuse opacity of children and young adults. The need to use clinicopathologic correlation in assessing these lesions is of particular importance. Central giant cell granuloma is a relatively common jaw lesion of young adults that has an unpredictable behavior. Microscopic diagnosis is relatively straightforward; however, this lesion continues to be somewhat controversial because of its disputed classification (reactive versus neoplastic) and because of its management (surgical versus. medical). Its relationship to giant cell tumor of long bone remains undetermined.