Primordial odontogenic tumor: An immunohistochemical profile.

BACKGROUND: Primordial Odontogenic Tumor (POT) is a recently described odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla, covered by cuboidal to columnar epithelium that resembles the internal epithelium of the enamel organ, surrounded at least partly by a delicate fibrous capsule. The purpose of this study was to investigate the possible histogenesis and biological behavior of this rare tumor by means of a wide immunohistochemical analysis of its epithelial and mesenchymal components. MATERIAL AND METHODS: The immunoexpression of twenty-three different antibodies were evaluated in four cases of POT. RESULTS: The epithelial cells that cover the periphery of the tumor showed immunopositivity for Cytokeratins 14 and 19, while Amelogenin, Glut-1, MOC-31, Caveolin-1. Galectin-3, PITX2, p53, Bax, Bcl-2, Survivin and PTEN were variably expressed in focal areas. The mesenchymal component of the tumor was positive for Vimentin, Syndecan-1, PITX2, Endoglin (CD105), CD 34, Cyclin D1, Bax, Bcl-2, Survivin and p53. PTEN and CD 90 showed a moderate positivity. BRAF V600E and Calretinin were negative in all samples. Cell proliferation markers (Ki-67, MCM-7) were expressed in <5% of the tumor cells. CONCLUSIONS: According to these immunohistochemical findings, we may conclude that POT is a benign odontogenic tumor in which there is both epithelial and mesenchymal activity during its histogenesis, as there is expression of certain components in particular zones in both tissues that suggests this tumor develops during the immature (primordial) stage of tooth development, leading to its inclusion within the group of benign mixed epithelial and mesenchymal odontogenic tumours in the current World Health Organization classification of these lesions.

Comparative histological and immunohistochemical study of ameloblastomas and ameloblastic carcinomas.

BACKGROUND: This study aimed to compare the histological and immunohistochemical characteristics of ameloblastomas (AM) and ameloblastic carcinomas (AC). MATERIAL AND METHODS: Fifteen cases of AM and 9 AC were submitted to hematoxilin and eosin (H&E) and immunohistochemical analysis with the following antibodies: cytokeratins 5,7,8,14 and 19, Ki-67, p53, p63 and the cellular adhesion molecules CD138 (Syndecan-1), E-cadherin and ß-catenin. The mean score of the expression of Ki-67 and p53 labelling index (LIs) were compared between the groups using the t test. A value of p<0.05 was considered to be statistically significant. RESULTS: All cases were positive for CKs 5, 14 and 19, but negative for CKs 7 and 8. CKs 5 and 19 were positive mainly in the central regions of the ameloblastic islands, while the expression in AC was variable in intensity and localization. CK14 was also variably expressed in both AM and AC. Ki-67 (P=.001) and p53 (P=.004) immunoexpression was higher in AC. All cases were positive for p63, but values were higher in AC. CD138 was mainly expressed in peripheral cells of AM, with a weak positivity in the central areas, while it was positive in most areas of ACs, except in less differentiated regions, where expression was decreased or lost. E-cadherin and ß-catenin were weakly positive in both AM and AC. CONCLUSIONS: These results shows that Ki-67, p53 and p63 expression was higher in AC as compared to AM, suggesting that these markers can be useful when considering diagnosis of malignancy, and perhaps could play a role in malignant transformation of AM. Pattern of expression of CKs 5 and 19 in AC were different to those found in AM, suggesting genetic alterations of these proteins in malignant cells. It was confirmed that CK19 is a good marker for benign odontogenic tumors, such as AM, but it is variably expressed in malignant cases.

Tissue microarray use for immunohistochemical study of ameloblastoma.

BACKGROUND: Ameloblastoma is a locally aggressive odontogenic tumor with high rates of recurrence. To better understand the molecular basis of ameloblastoma, tissue microarray (TMA) may represent a useful tool. However, despite TMA has been considered a high-throughput technique for different human neoplasms, it remains to be validated in the ameloblastoma context. Therefore, the objective of this study was to validate TMA for immunohistochemical study of ameloblastoma, determining its most appropriate design. METHODS: Forty cases of ameloblastoma were manually distributed in two TMA blocks assembled in triplicate containing 1.0- and 2.0-mm cores (20 cases each). Immunohistochemistry for cytokeratins 14 and 19, and Bcl-2 and Ki-67 was performed, and semiquantitative analysis was performed. Results obtained with TMA sections were compared to their corresponding conventional whole-section slides (CWSS). RESULTS: Kappa statistical test demonstrated that both 1.0- and 2.0-mm cores assessed as duplicate or triplicate significantly correlated with CWSS, with higher levels obtained using Ki67 (k = 0.98, 0.97, 0.88, 0.87) and CK19 (k = 0.62, 0.58, 0.85, 0.85). There was no significant difference between 1.0- and 2.0-mm cores, and between duplicate and triplicate values. 1.0-mm TMA showed a higher index of core loss (33.74% vs. 4.99%). CONCLUSION: Using a manual arrayer, it was demonstrated that 1.0-mm TMA arranged in duplicate is a valid method for ameloblastoma immunohistochemical study with satisfactory levels of agreement between TMA cylinders and CWSS.

Does cytokine profiling of aspirate from jaw cysts and tumors have a role in diagnosis?

PURPOSE: The objective of the present study was twofold: first, to assess aspirates for use in cytokine profiling and second, to initiate pilot analyses to determine whether the cytokine profiling can serve as an aid in the diagnosis of jaw lesions. MATERIALS AND METHODS: The aspirates from 12 benign odontogenic cysts and tumors of the jaw were collected and randomized, and a formal incisional biopsy was performed to establish the tissue diagnosis. The biopsies revealed keratocystic odontogenic tumor, ameloblastoma, and dentigerous cyst. The cystic aspirate was analyzed using the Q-Plex Human Cytokine Screen to detect cytokine expression and determine the level of expression for each pathologic entity. An array of 16 cytokines was investigated, including interleukin (IL)-1α, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IL-23, interferon-γ, tumor necrosis factor (TNF)-α, and TNF-ß. Tables were developed to determine the ratio of expression for the candidate cytokine pairs that were differentially expressed among the 3 pathologic entities encountered. One-way analysis of variance was used to search for significant differences in the ratio of expression of the candidate pairs among the 3 entities. RESULTS: Cytokines expressed by the 3 distinct jaw lesions were detected in the aspirate without the need for tissue biopsy. Cytokine profiling of these entities is possible owing to differential expression of the various cytokines studied. The ratio of expression was significant (P < .05) for 15 pairs of cytokines: IL-5/IL-1α, IL-4/IL-2, IL-8/IL-4, TNF-ß/IL-6, IL-23/IL-6, TNF-α/IL-23, TNF-α/TNF-ß, TNF-α/IL-8, TNF-ß/IL-5, TNF-ß/TNF-α, TNF-ß/IL-13, IL-12/IL-23, IL-13/IL-15, IL-15/IL-2, and IL-6/IL-2. A comparison of the mean values indicated a "high/low" expression value for each lesion type for the 15 cytokine pairs. CONCLUSIONS: Cytokines, expressed by the 3 groups of jaw lesions, can be detected in the cystic aspirate, and a comparison of the ratio of the expression of the aspirates demonstrated a differential expression pattern of cytokines among the 3 groups. These ratios could assist in establishing a prompt and accurate diagnosis of lesions that might be difficult to discern clinically and radiographically. The use of a simple, minimally invasive aspiration procedure can help to establish an accurate diagnosis.

Immunoglobulin and glucose-6-phosphate dehydrogenase as markers of cellular origin in Burkitt lymphoma.

Two independent marker systems, G-6-PD isoenzymes and cell membrane-associated IgM, were used to trace the cellular origin of Burkitt lymphoma. Application of the G-6-PD system is dependent upon the fact that, in accordance with inactivity of one X chromosome in each somatic cell, females heterozygous for the usual B gene (Gd(B)) at the X-linked G-6-PD locus and the variant allele Gd(A) (or Gd(A-)) have two types of cells. Gd(B) is active in one cell population, which consequently produces B type enzyme; in the other population Gd(A) is active, producing the variant A enzyme. Therefore, tumors with a clonal origin in a Gd(B)/Gd(A) heterozygote should exhibit only one enzyme type (B or A) whereas those with multicellular origin may show both A and B enzymes. Utilization of the immunoglobulin system is based upon the supposition that in lymphoid neoplasms with clonal origin either all or none of the tumor cells should have surface-associated IgM and kappa-reactivities. 33 of 34 relatively homogeneous (with respect to content of neoplastic cells) individual Burkitt tumors from 19 G-6-PD heterozygotes had single enzyme phenotypes. Similarly, of 95 tumors tested, 92 consisted essentially of IgM(+) or (-) cells. Two neoplasms could not be definitely classified and one tumor had two cell populations. These data suggest a clonal origin for most Burkitt tumors, but the one neoplasm with a double G-6-PD phenotype (A/B) and the one tumor that had two populations of cells with respect to surface IgM, could have originated from multiple cells. G-6-PD was determined in each of two tumors from seven heterozygotes and in all cases both tumors had the same single enzyme phenotype. Surface-associated IgM was tested in four tumors from one patient, three from another, and in two neoplasms from 11 patients. With one exception, all tumors from the same patient were concordant with respect to IgM. These findings suggest that the entire disease has a clonal origin, i.e., it emerges at one focus and then spreads to other parts of the body. Cells from 36 recurrent neoplasms were typed for G-6-PD (in heterozygotes) and/or IgM. In one previously reported patient, initial and recurrent tumors were discordant for G-6-PD. Two other patients had IgM phenotypes in recurrences that were discordant with those found in their initial tumors. Phenotypes from three of nine relapses which occurred after 5 mo were discordant for G-6-PD or IgM but no discordance was detected among 27 earlier recurrences. Thus, some "late" recurrences may be due to emergence of "new" maligant cell lines whereas most early relapses are due to reemergence of the original malignant clones. The probable unicellular origin of Burkitt lymphoma and the findings in tumor recurrences are discussed in terms of the disease's putative viral etiology.

The immunoprofile of odontogenic keratocyst (keratocystic odontogenic tumor) that includes expression of PTCH, SMO, GLI-1 and bcl-2 is similar to ameloblastoma but different from odontogenic cysts.

BACKGROUND: The aggressive biological behavior of odontogenic keratocysts (OKCs), unlike that of other odontogenic cysts, has argued for its recent re-classification as a neoplasm, 'keratocystic odontogenic tumor'. Identification of mutations in the PTCH gene in some of the OKCs that were expected to produce truncated proteins, resulting in loss of control of the cell cycle, provided additional support for OKCs having a neoplastic nature. METHODS: We investigated the immunohistochemical expression of the sonic hedgehog (SHH) signaling pathway-related proteins, PTCH, smoothened (SMO) and GLI-1, and of the SHH-induced bcl-2 oncoprotein in a series of primary OKC (pOKC), recurrent OKC (rOKC) and nevoid basal cell carcinoma syndrome-associated OKCs (NBCCS-OKCs), and compared them to solid ameloblastomas (SAMs), unicystic ameloblastomas (UAMs), 'orthokeratinized' OKCs (oOKCs), dentigerous cysts (DCs) and radicular cysts (RCs). RESULTS: All studied lesions expressed the SHH pathway-related proteins in a similar pattern. The expression of bcl-2 in OKCs (pOKCs and NBCCS-OKCs) and SAMs was significantly higher than in oOKCs, DCs and RCs (P < 0.001). CONCLUSIONS: The present results of the immunoprofile of OKCs (that includes the expression of the SHH-related proteins and the SHH-induced bcl-2 oncoprotein) further support the notion of OKC having a neoplastic nature. As OKCs vary considerably in their biologic behavior, it is suggested that the quality and quantity of interactions between the SHH and other cell cycle regulatory pathways are likely to work synergistically to define the individual phenotype and corresponding biological behavior of this lesion.

CD34 staining density predicts giant cell tumor clinical behavior.

PURPOSE: To evaluate the staining density of CD34, a glycoprotein expressed in hematopoetic precursor and capillary endothelial cells, as a molecular marker for predicting clinical behavior of giant cell tumors. MATERIALS AND METHODS: This was a retrospective study of patients with giant cell lesions of the jaws treated over a 15-year period. The primary predictor variable was mean CD34 staining density. The outcome measure was giant cell tumor clinical behavior (aggressive vs nonaggressive). Bivariate analyses were computed to evaluate the association between the predictors and outcome. A receiver-operator characteristic (ROC) curve was used to establish the threshold for a positive diagnostic test. A logistic regression model was used to evaluate the association between the clinical behavior and a positive test. A value of P

Evaluation of tumor-infiltrating lymphocytes in osteosarcomas of the jaws: a multicenter study.

The aim of the present study was to investigate the profile of tumor-infiltrating lymphocytes (TIL) in osteosarcomas of the jaws (OSJ). A total of 21 OSJ samples were analyzed in a retrospective and cross-sectional multicenter study. Immunohistochemistry was performed to determine the recognition of TIL such as CD4+, CD8+, granzyme B+ (GrB), programmed cell death protein+ (PD-1), and cytotoxic T lymphocyte-associated antigen 4+ (CTLA-4) in intratumoral and peripheral (stromal) regions. Positivity was determined based on the percentage and density of TIL+ per square millimeter [1 = absent (< 25 cells/mm2), 2 = low (25 to 130 cells/mm2), and 3 = high (> 130 cells/mm2)]. The association of TIL density with clinicopathologic data was determined by the Mann-Whitney test (p < 0.05). OSJ were positive for CD8+ cells in 45% (n = 9) of cases, for CD4+ cells in 30% (n = 6) of cases, and for CTLA-4+ in 4.8% (n = 1) of cases, with a score of 2 (low TIL) in all cases. All cases were negative for GrB and PD-1 (score 1). No association was observed between immune infiltrate and clinicopathologic findings. OSJ showed a microenvironment with low TIL, including failure of effectiveness of the antitumor immune response (absence of GrB+ cells), and few cells exhibited immunotherapeutic targets, such as CTLA-4 and PD-1.

Evaluation of HLA-G, HLA-E, and PD-L1 proteins in oral osteosarcomas.

OBJECTIVE: The aim of this study was to investigate the expression of human leukocyte antigens (HLAs) G and E and programmed death-ligand 1 (PD-L1) in oral osteosarcoma (OO) (n = 13). The relationship between the expression of these molecules and histologic grading and metastasis was also evaluated. STUDY DESIGN: HLA-G, HLA-E, and PD-L1 were identified by immunohistochemistry. Samples of normal bone tissue (n = 6) were used as controls. The sections were evaluated using a semiquantitative scoring system with an immunoreactive score, where a score of 0 was considered absent, ≤2 was low, and >2 was high expression. RESULTS: We identified high expression of HLA-G, HLA-E, and PD-L1 by malignant osteoblastic cells in 69.2% of OO cases, which was statistically higher than that in controls (P < .05). Overexpression of these proteins was identified in 8 of 11 samples of high-grade and 1 of 2 samples of low-grade OO. Additionally, 66.6% of patients with metastases (n = 4) and 71.4% of patients without metastases (n = 5) had high expression of HLA-G, HLA-E, and PD-L1 in tumor samples (P > .05). CONCLUSION: OO had high expression of HLA-G, HLA-E, and PD-L1 irrespective of clinicopathologic parameters, including histologic grading and metastasis.

Immunoexpression of BMP-2 and BMP-4 and their receptors, BMPR-IA and BMPR-II, in ameloblastomas and adenomatoid odontogenic tumors.

OBJECTIVES: The present study evaluated the immunohistochemical expression of BMP-2 and BMP-4 and of their receptors (BMPR-IA and BMPR-II) in solid ameloblastoma (SA), unicystic ameloblastoma (UA) and adenomatoid odontogenic tumor (AOT) in order to obtain a better understanding of their role in the development and biological behavior of these tumors. DESIGN: This study analyzed these proteins in 30 cases of SA, 10 cases of UA, and 30 cases of AOT. Immunoexpression was evaluated in the parenchyma and stroma by attributing the following scores: 0, no stained cells; 1, ≤10%; 2, >10% and ≤25%; 3, >25% and ≤50%; 4, >50% and ≤75%.; 5, >75% stained cells. RESULTS: In SAs, positive correlations were observed between the stromal and parenchymal expression of BMP-2 (p<0.001) and between the stromal expression of BMP-2 and BMP-4 (p=0.020), as well as between the stromal expression of BMPR-II and BMP-4 (p=0.001) and the stromal and parenchymal expression of BMPR-II (p<0.001). In UAs, correlations were detected between the stromal and parenchymal expression of BMP-4 (p=0.035) and between the stromal expression of BMP-4 and BMPR-IA (p=0.022). In AOTs, analysis of immunoexpression in the parenchyma revealed positive correlations between all proteins. CONCLUSION: BMPs and their receptors play an important role in the differentiation and development of ameloblastomas and AOTs, but may not explain the different biological behaviors of these lesions. The positive correlation observed in AOTs might be related to the formation of mineralized material in this tumor.

Immunological status of patients with denture stomatitis and yeast infection after treatment of maxillofacial tumors.

Therapeutic modalities employed in the treatment of maxillofacial malignancy, tumor resection, radiation and chemotherapy, can result in local and systemic changes in healthy oral tissues many years after anticancer therapy has been stopped. The immunologic status of a select group of nine individuals who underwent surgery of the maxillofacial region and after head and neck irradiation, with severe and persistent denture stomatitis was studied. A significant impairment of granulocyte and lymphocyte functions and increased concentrations of serum IgG, as compared to healthy controls, were found in the patients of the study group. It is concluded, that this group of patients show immunological abnormalities many years post therapy, which must be recognized by the clinician in order to effect a cure.

Ki-67 expression in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts.

This study investigated whether or not an ameloblastoma developing in the wall of a dentigerous cyst is a distinct lesion from the unicystic ameloblastoma. An immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising in dentigerous cysts was done. The values of Ki-67 positivity were 3.14 for the dentigerous cyst, between 5.32 and 16.56 for unicystic ameloblastoma, and 11.77 for ameloblastoma arising in a dentigerous cyst. Statistically significant differences were found between the dentigerous cyst and the unicystic ameloblastoma and between the dentigerous cyst and the ameloblastoma arising from a dentigerous cyst. No statistically significant difference was present between unicystic ameloblastoma and ameloblastoma arising from dentigerous cyst. These immunohistochemical data confirm the hypothesis that an ameloblastoma arising from a dentigerous cyst has a similar biological behavior to the unicystic ameloblastoma and should be considered as merely a histologic variant.

Granular cell ameloblastoma. An immunocytochemical study.

Granular cell ameloblastoma is characterized by nests of large, eosinophilic granular cells. These latter have long been the subject of debate. Two cases of granular cell ameloblastomas have been immunocytochemically stained with a panel of antibodies against human mitochondria, S-100 protein, CD 68, low molecular weight cytokeratins, chromogranin, laminin, vimentin, PCNA, bcl-2 and p-53. Granular cells exhibited a membranous positivity with cytokeratins while the non granular cells of the same tumors showed a diffuse cytoplasmic reactivity. Moreover, granular cells showed marked cytoplasmic positivity with CD68 antiserum only while human mitochondria, as well as S-100 protein antisera, were consistently negative. PCNA, bcl-2 and p-53 did not stain the granular cells. These results allow easy distinction of granular cell ameloblastomas from similar tumors exhibiting granular cell changes and indicate that the granularity in ameloblastoma cells is consequent to lysosomal overload.

[The immunological prognosis of complications in patients undergoing reconstructive operations after the radiation therapy of malignant tumors of the maxillofacial area and neck]. / Immunologicheskoe prognozirovanie oslozhnenii u bol'nykh posle luchevoi terapii zlokachestvennykh opukholei cheliustno-litsevoi oblasti i shei pri provedenii rekonstruktivnykh operatsii.

Immunologic studies were carried out in 55 patients with local malignant processes in the maxillofacial area and neck before and after surgery. The patients were divided into 2 groups: group 1 (N = 20) received no specific therapy before surgery, group 2 (n = 35) were administered radiotherapy in a total focal dose of 56-65 Gy before the operation. The findings evidence that radiotherapy augments B and T system immunodeficiency manifestations after surgical stress. Postoperative complications in the patients administered radiotherapy before surgery are due to not only immunodeficiency, but to the initial presence of an infective agent as well. Immunocorrective therapy before and after surgery may be recommended to patients whose immunity parameters are shifted.

Immunoglobulin G4-related disease of the maxillofacial region: a rare case / Enfermedad relacionada con inmunoglobulina G4 en el área maxilofacial: un caso raro

IgG4-related disease is a systemic, multifocal, immune-mediated disorder that can affect multiple organs and may present as a tumor, with rare cases described in the maxillofacial region. A female patient, 53 years old, presenting tumor-like mass in the right mandibular region. Magnetic resonance imaging suggested well circumscribed nodular lesion adjacent to the branch / body of the mandible, extending posteriorly to the masseter muscle. During the surgical procedure of excision, a lesion was observed adhering to the right masseter muscle, but it was possible to remove it completely. Histopathological and immunehistochemical analysis suggested diagnosis of IgG4-related disease, furthermore, IgG4 serum count was increased. Actually, the patient continues on periodical followups in our service and by other specialties. Can be concluded that precise diagnosis of this pathology depends on many factors, being challenging and the treatment involves multidisciplinary evaluation due to the possibility of involvement of several other organs.

La enfermedad relacionada con IgG4 es una condición sistémica, multifocal, mediada por una alteración de la respuesta inmune que puede afectar diferentes órganos o puede presentarse como un tumor, raramente descrito en el área maxilofacial. Se describe el caso de una paciente de sexo femenino de 53 años de edad, presentando una masa tumoral en el ángulo mandibular derecho. La resonancia magnética sugirió un área nodular bien delimitada adyacente al cuerpo mandibular y extendida posteriormente hasta el musculo masetero. Durante la escisión quirúrgica, la lesión se presentaba adherida al musculo de forma lateral siendo posible el retiro total de la lesión. El estudio histopatológico e inmunohistoquimico determinó el diagnóstico de enfermedad relacionada con IgG4 presentando un conteo de igG4 aumentado. Actualmente, la paciente continua con seguimiento por la especialidad. Se puede concluir que el diagnóstico preciso de esta patología depende de algunos factores; el tratamiento debe ser multidsciplinario debido a la inclusión de diferentes órganos en la enfermedad.

Immunolocalisation of laminin-1 in keratocystic odontogenic tumors.

Keratocystic odontogenic tumors (KOTs) are distinct odontogenic lesions frequently affecting the jawbones. They may be associated with nevoid basal cell carcinoma syndrome (NBCCS), and may exhibit disorders involving the extracellular matrix. The aim of this study was to investigate the immunolocalisation of laminin-1 in 20 cases of KOTs in order to contribute to the characterization of this protein, which is little studied in odontogenic tumors. Our results showed laminin-1 in all 20 KOTs studied; its labelling intensity was weak in three cases (15%), moderate in five (25%) and strong in 12 cases (60%). Laminin-1 immunolocalisation was predominantly continuous in 18 (90%) KOTs, including areas of acanthosis, subepithelial split and epithelial buds. Weak immunolabelling was observed in regions exhibiting an inflammatory process, especially in the case of intense inflammation. These findings suggest that laminin-1 does not participate in biological processes such as cystic epithelium-cystic wall separation or the formation of epithelial islands in KOTs. Furthermore, the discontinuous and weak labelling of this protein in the basement membrane of these tumors is probably a consequence of the inflammatory process in the tumor stroma.