What Is the Non-calcifying Langerhans Cell-Rich Variant of Calcifying Epithelial Odontogenic Tumor?

CD1a is not effective in distinguishing calcifying epithelial odontogenic tumors from amyloid-rich central odontogenic fibroma

OBJECTIVE

Differential diagnosis between the non-calcifying variant of calcifying epithelial odontogenic tumor (NCLC-CEOT) and amyloid-rich central odontogenic fibroma (AR-COdF) has become a debate, particularly regarding the frequency of CD1a positivity in both entities. This has led to the growing consensus that CD1a-positive staining in AR-NC lesions confirms the diagnosis of AR-COdF. Here, we assess the validity of this consensus.

STUDY DESIGN

We collected the data of a case series of histopathologically distinct CEOTs, NCLC-CEOTs, and COdFs and stained them for CD1a and amyloid. Of the 9 CEOTs and NCLC-CEOTs, we diagnosed 4 as classic, 3 as associated with a dentigerous cyst, and 2 as combined CEOT/adenomatoid odontogenic tumors. Of the 9 COdFs, we diagnosed 3 as epithelial poor, 3 as epithelial rich (lacking amyloid), 2 as hyalinized with amyloid, and 1 as hyalinized without amyloid and assessed the staining results.

RESULTS

Of the 9 CEOTs and NCLC-CEOTs, 7 stained positively for CD1a, 5 diffusely and 2 focally. Notably, 2 classic NCLC-CEOTs stained strongly CD1a positive. All 3 of the epithelial-poor COdFs were predictably CD1a negative. Of the 6 remaining COdFs, 2 were CD1a positive, 1 hyalinized-with-amyloid COdF diffusely and 1 epithelial-rich-without amyloid focally.

CONCLUSIONS

CD1a positivity, which occurs in classic CEOT and NCLC-CEOT, does not help distinguish between NCLC-CEOT and AR-COdF and is inconsistent in all AR-COdFs. The diagnosis of CEOT and AR-COdF should be guided by appropriate histopathologic criteria irrespective of CD1a staining or the presence of amyloid or calcifications.

Non-Calcifying/Langerhans Cell-Rich Calcifying Epithelial Odontogenic Tumour: A Critical Review of the Rare and Distinctive Entity

BACKGROUND

The study aims to analyse the non-calcifying/Langerhans cell rich (NCLC) subtype of calcifying epithelial odontogenic tumour (CEOT).  METHOD: The features of cases of the NCLC subtype of CEOT noted in the English literature by PubMed as well as 3 new cases were reviewed.

RESULTS

Overall, twenty-one cases were noted. Many were women in the fourth to sixth decades (male-to-female ratio =1 to 2). Radiologically, the lesion is often unilocular with resorption of the affected teeth. Nineteen of the 21 cases occurred in the maxilla, especially the anterior portion. On pathological examination, epithelial cells are noted in non-calcifying amyloid-rich fibrous stroma. The main differential diagnosis is the amyloid subtype of central odontogenic fibroma. Immunohistochemical studies revealed the tumour epithelial cells were positive for cytokeratins and p63 and contained CD1a, S-100, and langerin-positive Langerhans cells. On a median follow-up of 2 years, one patient had a recurrence one year after curettage.

CONCLUSION

The NCLC subtype of CEOT is unique as it contains significant numbers of Langerhans cells and has clinicopathological features distinctive from classic CEOT.

Central odontogenic fibroma with amyloid: a diagnostically challenging case

Odontogenic fibroma is a rare benign mesenchymal odontogenic tumor, with its histological diversity possibly posing diagnostic challenges. A case of the amyloid variant of central odontogenic fibroma, with epithelial cells in perineural and intraneural locations, is reported herein. The 46-year-old female patient had experienced discomfort related to her anterior right hard palate for approximately 25 years. Clinical examination revealed a depression in the anterior hard palate, and radiographic examination showed a well-defined radiolucent lesion with root resorption of the adjacent teeth. Histologically, the well-circumscribed tumor was composed of hypocellular collagenous connective tissue with small islands of odontogenic epithelium. In addition, the juxta-epithelial deposition of amyloid globules without calcification and epithelial cells in perineural and intraneural locations were observed, which posed a diagnostic challenge in differentiating the lesion from the non-calcifying variant of calcifying epithelial odontogenic tumor and sclerosing odontogenic carcinoma. However, on the basis of the clinical and radiographic findings, which were suggestive of a benign and slowly progressive process given the corticated, unilocular radiolucency, the considerable root resorption, and the long history of this finding in an otherwise healthy patient, the final diagnosis was amyloid variant of central odontogenic fibroma. Increased recognition of this variant of odontogenic fibroma and its differentiation from other more aggressive lesions could help the clinician to avoid overdiagnosis and overtreatment.

Non-calcifying Langerhans Cell Rich Variant of Calcifying Epithelial Odontogenic Tumor and Amyloid Rich Variant of Central Odontogenic Fibroma: A Unique Entity or a Spectrum?

Overlapping clinicopathological features of non-calcifying Langerhans cell rich variant of calcifying epithelial odontogenic tumor (NCLC-CEOT) and the amyloid rich variant of the central odontogenic fibroma (AR-COF) have been recognized recently. It is still under debate whether these two diseases are indeed one unique disease entity or belong to CEOT and COF, respectively. To clarify this issue, we have performed a literature review to compare the similarities and differences in clinicopathological features among NCLC-CEOT, AR-COF, classic CEOT, and classic COF. We aimed to investigate whether NCLC-CEOT and AR-COF might be the same and one distinctive disease entity, or a variant (or variants) of either CEOT or COF; or whether COF, NCLC-CEOT/AR-COF, and CEOT represented a histopathological spectrum of one disease. Our results indicate that NCLC-CEOT and AR-COF cases share many similar clinicopathological features. Thus, we suggest that they are the same disease entity. Due to nearly no reported recurrence of NCLC-CEOT/AR-COF cases, the conservative surgical treatment is appropriate. The NCLC-CEOT/AR-COF cases show some overlapping clinicopathological features with COF rather than the CEOT cases. However, differences in the clinicopathological features are still recognized among the NCLC-CEOT/AR-COF, COF, and CEOT cases. Future research, particularly molecular biological studies, may further elucidate their relationships and assist proper classification of the NCLC-CEOT/AR-COF cases.

An Unusual Maxillary Tumor with Tubuloductal Epithelial Structures, Solid Epithelial Nests and Stromal Odontogenic Ameloblast-Associated Protein Deposits. Tubuloductal/Syringoid Variant of Central Odontogenic Fibroma with Amyloid?

Glandular tumors of jaw bones present, most often, histopathologic features of salivary gland and, rarely, of cutaneous glandular neoplasms. They are thought to originate from odontogenic epithelium. An unusual maxillary tumor presenting as a radiolucency in the periapical area of the right permanent lateral incisor of a 74-year-old male is presented causing root resorption. Preparations revealed occasionally branching tubular cords and ductal structures characterized, mostly, by a bilayer composed of luminal cuboidal to low columnar cytokeratin (CK) 7, Ber-EP4 and occasionally CK8/18 positive cells, and abluminal, CK5/6 positive, basal/basaloid cells revealing nuclear reactivity for p63/p40. Smooth muscle actin and calponin were negative, save for a single focus of calponin positive cells, confirming absence of myoepithelial support or epithelial mesenchymal transition. CK19 exhibited staining of both layers, the luminal being more intense. Eosinophilic secretory material and, occasionally, a luminal pellicle were decorated with CK8/18 and polyclonal carcinoembryonic antigen (CEA). CD1a identified only rare Langerhans' cells and Ki67 decorated 1-2% of abluminal cell nuclei. Small solid nests of epithelial cells were also present. Infrequently, an apparent transition of a nest into a tubular structure was appreciated. The partially inflamed stroma featured multiple hyalinized acellular deposits consistent with amyloid, as confirmed by bright orange Congo red reactivity with apple-green birefringence, which reacted with odontogenic ameloblast-associated (ODAM) protein antibody but not with antibodies for amelotin and secretory calcium-binding phosphoprotein proline-glutamine rich 1. Based on the above, the diagnosis of tubuloductal/syringoid variant of central odontogenic fibroma with ODAM amyloid is favored.

Noncalcifying clear-cell variant of calcifying epithelial odontogenic tumor: A case report and review

Clear-cell tumors of the head and neck are biologically diverse consisting of benign, malignant and metastatic lesions. These tumors pose a diagnostic challenge. In the oral cavity, these may be derived from odontogenic/nonodontogenic epithelium or from mesenchyme or can be metastatic. Odontogenic tumors with clear-cell change are rare. Calcifying epithelial odontogenic tumor (CEOT) is a rare, benign, locally aggressive odontogenic epithelial tumor affecting the jaw. Here, we report a case of clear-cell variant of CEOT with its histopathological differential diagnosis. A 43-year-old male patient with swelling in his lower right back tooth region showed a well-defined radiolucent lesion with smooth corticated periphery on radiograph. On incisional biopsy, tumor showed small sheets, cords and islands of odontogenic epithelium with nests of clear cells with no evidence of calcification. A final diagnosis of CEOT was established by differentiating other odontogenic and nonodontogenic lesions on the basis of clinical, radiographic, histopathologic and special stain features.

Odontogenic fibroma amyloid-variant: a typical case and brief considerations about mimickers

The World Health Organization's (WHO) updated classification of head and neck tumors (2017) defined odontogenic fibroma as a rare neoplasm. In this report, we describe an unusual, typical and rare variant of a central odontogenic fibroma with diffuse amyloid-like protein stromal deposition, and discuss the differential diagnosis with other entities. Radiographically, this lesion presented as a well-defined radiolucency of the mandible, partially cystic. Histologically, the lesion showed a unique confluence of odontogenic epithelial rests in a moderately cellular connective tissue. Immunohistochemical staining highlighted a mixture of benign epithelial and Langerhans cells within connective tissue with diffuse amyloid-like stromal deposition. The importance of recognizing this variant of odontogenic fibroma is due to its benign prognosis and clinical course.

Calcifying epithelial odontogenic tumor: a case series spanning 25 years and review of the literature

OBJECTIVE

The calcifying epithelial odontogenic tumor (CEOT) is a rare benign neoplasm that makes up less than 1% of all odontogenic tumors. This study aims to describe a case series of CEOT spanning 25 years and to review and compare our results with the existing literature.

STUDY DESIGN

With institutional review board approval, all CEOT archival cases from the University of Florida Oral Pathology Biopsy Service between 1994 and 2019 were retrieved. A total of 20 cases were included. Based on current criteria, 2 cases that stained positively for CD1 a were excluded, because these most likely represented the amyloid-rich variant of central odontogenic fibroma.

RESULTS

Average patient age was 40 years. Females and males were affected equally (n = 10). The mandible was more commonly involved (60%, n = 12) than the maxilla (40%, n = 8). CEOT variants included incipient CEOT (10%, n = 2) and peripheral CEOT (10%, n = 2). One case exhibited features of adenomatoid odontogenic tumor in addition to CEOT. Congo red staining for amyloid was performed in 13 cases, all of which were positive.

CONCLUSION

Our results align with the literature. Awareness of the different variants of CEOT and of the separate but similar-appearing amyloid-rich variant of central odontogenic fibroma will help to ensure accurate diagnosis and appropriate treatment.

Central odontogenic fibroma: an international multicentric study of 62 cases

OBJECTIVE

The aim of this study was to report the clinicopathologic features of 62 cases of central odontogenic fibroma (COdF).

STUDY DESIGN

Clinical and radiographic data were collected from the records of 13 oral pathology laboratories. All cases were microscopically reviewed, considering the current World Health Organization classification of tumors and were classified according to histopathologic features.

RESULTS

There were 43 females and 19 males (average age 33.9 years; range 8-63 years). Clinically, COdF lesions appeared as asymptomatic swellings, occurring similarly in the maxilla (n = 33) and the mandible (n = 29); 9 cases exhibited palatal depression. Imaging revealed well-defined, interradicular unilocular (n = 27), and multilocular (n = 12) radiolucencies, with displacement of contiguous teeth (55%) and root resorption (46.4%). Microscopically, classic features of epithelial-rich (n = 33), amyloid (n = 10), associated giant cell lesion (n = 7), ossifying (n = 6), epithelial-poor (n = 3), and granular cell (n = 3) variants were seen. Langerhans cells were highlighted by CD1a staining in 17 cases. Most patients underwent conservative surgical treatments, with 1 patient experiencing recurrence.

CONCLUSIONS

To the best of our knowledge, this study represents the largest clinicopathologic study of COdF. Most cases appeared as locally aggressive lesions located in tooth-bearing areas in middle-aged women. Inactive-appearing odontogenic epithelium is usually observed within a fibrous/fibromyxoid stroma, occasionally exhibiting amyloid deposits, multinucleated giant cells, or granular cells.

CEOT Variants or Entities: Time for a Rethink? A Case Series with Review of the Literature

The first detailed description of calcifying epithelial odontogenic tumor (CEOT) are ascribed to Jens Pindborg, but this tumor was described some years previously. Subsequently, CEOT was included in the 1971 WHO classification of odontogenic tumors and a since then number of variants have been described, which have added confusion to the diagnostic criteria. We aimed to survey the literature on the variants of CEOT, in parallel with a review of our single institution experience of CEOTs. Cases identified were collated, including available clinical, radiological and histological information and then reviewed, taking into account changes in the understanding and classifications of odontogenic tumors since initial diagnosis. We identified 26 cases from 1975 to 2017 for which histological material was available. Of these, only 13 (50%) showed the "classic" histological appearance, whilst two cases were identified as recognized variants. In 11 cases, other diagnoses or a differential diagnosis were preferred, with no agreed diagnosis in four of these. The proliferation fraction (Ki67) in the 10 cases tested was 2.1% ± 0.18. These findings illustrate the diagnostic challenges in this group of tumors and highlight the gaps in knowledge. Techniques, such as EWSR1 gene cytogenetic analysis, may be helpful in cases with clear cells. However, in other areas of controversy, including the non-calcifying and Langerhans cell rich variants, further investigation, perhaps utilizing sequencing technologies may be needed to refine the classification. Owing to the relative rarity of these lesions it would be beneficial if future work could be pursued as an international collaboration.

Update on Odontogenic Tumors: Proceedings of the North American Head and Neck Pathology Society

Odontogenic tumors are rare entities, often derived from the epithelial remnants in the gnathic bones following odontogenesis. This brief manuscript will seek to address recent developments pertaining to odontogenic tumors as well as particularly uncommon odontogenic tumors and the difficulties in their diagnosis.