Immunosurveillance profile of oral squamous cell carcinoma and oral epithelial dysplasia through dendritic and T-cell analysis

Oral squamous cell carcinomas (OSCCs) can arise from potentially malignant disorders, such as leukoplakia. The immune system plays an important role recognizing tumour precursor cells. However, due to immuno-editing mechanisms cancer cells are able to escape immune system surveillance.

OBJECTIVE

To evaluate the profile of dendritic (Langerhans and plasmacytoid) and T cells in OSCC and oral epithelial dysplasia (OED) and correlate these findings with clinical data.

MATERIALS AND METHODS

Fifty cases of OSCC and 48 of OED were immunostained for CD1a and CD83 dendritic Langerhans cells (DLC), CD303 plasmacytoid dendritic cells (pDC) and CD8 followed by quantitative analysis.

RESULTS

Analysis revealed a significant decrease in the number of mature CD83 DLC in OSCC compared with OED. CD303 positivity was significantly increased in the OSCC group when compared to OED. CD8-positive lymphocytes were significantly decreased in OSCC compared with OED lesions. No statistical correlation was found with clinical data.

CONCLUSION

The number of mature dendritic cells (DC) was decreased in OSCC compared with OED lesions suggesting that either these cells might have migrated to lymph nodes to present the tumour antigens and activate the immune system or cytokines secreted by the tumour microenvironment are inhibiting the adequate maturation of DLC. The numbers of pDC were significantly increased in the OSCC group compared with the OED group. This suggests they may play an important role in the defence against tumours although it is not clear whether this is promoting or inhibiting malignant progression.

Histomorphometric characterization of subgemmal neurogenous plaques

OBJECTIVES

The aim of this study was to characterize the histomorphometric features of subgemmal neurogenous plaques (SNPs) to better understand their relationship to surrounding microanatomy included in the tissue biopsy samples of the tongue.

STUDY DESIGN

A 12-year retrospective study on the files of 3 oral pathology centers yielded 28 SNPs. Hematoxylin and eosin-stained sections were used for histologic analysis, and immunohistochemical staining for S100 protein was performed to better characterize the neural structures. Slides were scanned and histomorphometric analysis carried out using ImageScope software.

RESULTS

Twenty-one women (75%) and 6 men (21.4%) comprised the sample (mean age 46.4 and 49 years, respectively). Twenty cases (71.4%) were juxtaposed to the tongue epithelium and 16 cases (57.1%) were associated with lymphoid tissue. The mean area of the SNPs was 0.160 mm², and the mean distance to the overlying epithelium was 0.312 mm.

CONCLUSIONS

SNPs are normal neural structures located on the posterior border of the tongue that represent a non-neoplastic regional anatomic variation. In some cases, signs or symptoms may be present, and further investigation should be performed. Pathologists should be aware of this entity to avoid confusion with neural lesions.

Epstein-Barr virus (EBV)--associated posttransplant lymphoproliferative disorder appearing as mandibular gingival ulcers

Posttransplant lymphoproliferative disorders (PTLDs) comprise a spectrum of complications that affect immunocompromised patients following hematopoietic stem cell transplantation or solid organ transplantation. Its incidence varies depending on the transplanted organ, occurring in approximately 2.3% of kidney transplantations. A 31-year-old woman was referred to the Dental Clinic of the State University of Western Paraná for evaluation of an oral lesion. Her medical history revealed a previous diagnosis of hypertension, Epstein-Barr virus (EBV) seropositivity, and kidney transplantation 12 years prior. She was under standard immunosuppressive therapy. Intraoral examination identified a gingival necrotic lesion with extension to the posterior right lower alveolar bone. An incisional biopsy was performed. Histologic examination showed lymphocytic proliferation of cells with small and hyperchromatic nuclei, atypical mitosis, and cells with large and pale nuclei showing prominent nucleoli permeating connective tissue, muscle fibers, and adipocytes. Correlation of clinical, histologic, and immunohistochemical findings led to a diagnosis of polymorphic EBV-associated PTLD rich in B and T cells.

Nuclear changes in oral mucosa of alcoholics and crack cocaine users

The effects of drugs of abuse on oral mucosa are only partly understood. The aims of the present study were to: (1) evaluate the frequency of nuclear changes in normal-appearing oral mucosa of alcoholics and crack cocaine users and (2) assess their association with cell proliferation rate. Oral smears were obtained from the border of the tongue and floor of the mouth of 26 crack cocaine users (24 males and 2 females), 29 alcoholics (17 males and 12 females), and 35 controls (17 males and 18 females). Histological slides were submitted to Feulgen staining to assess the frequency of micronuclei (MN), binucleated cells (BN), broken eggs (BE), and karyorrhexis (KR). A significant increase in the frequency of MN was observed in cells exfoliated from the tongue of crack cocaine users ( p = 0.01), and alcoholics showed a higher frequency of KR in cells obtained from the floor of the mouth ( p = 0.01). Our findings suggest that the use of crack cocaine induces clastogenic effects, whereas alcoholism is associated with higher degrees of keratinization in the floor of the mouth.

Central giant cell lesion: diagnosis to rehabilitation

Central giant cell lesion (CGCL) is a benign bone lesion of unknown etiology that primarily affects the mandible, with a predilection for female children and young adults. This article describes a case of a 16-year-old boy with a palatal swelling of approximately 18 months duration. Clinical, radiographic, histopathological, and hematological examinations led to a diagnosis of CGCL. Treatment involved a complete enucleation of the lesion and the removal of several teeth. A subsequent esthetic/functional rehabilitation was performed using a removable prosthesis. The patient was submitted to rigorous clinical and radiographic follow-ups, with no signs of recurrence over a 7-year period.

Photobiomodulation reduces oral mucositis by modulating NF-kB

The aim of this study was to evaluate NF-kB during 5-fluorouracil (FU)-induced oral mucositis and ascertain whether photobiomodulation (PBM), as a preventive and/or therapeutic modality, influences this transcription factor. Ninety-six male golden Syrian hamsters were allocated into four groups: control (no treatment); PBM therapeutic, PBM preventive, and PBM combined. Animals received an injection of 5-FU on days 0 and 2. On days 3 and 4, the buccal mucosa was scratched. Irradiation was carried out using a 660-nm, 40-mW diode laser at 6  J/cm(2) during 6  s/point, 0.24  J/point, for a total dose of 1.44  J/day of application. Animals were euthanized on days 0, 5, 10, and 15 (n=6). Buccal mucosa was removed for protein quantification by Western blot. Clinical analysis revealed that PBM groups exhibited less mucositis than controls on day 10. Control animals exhibited lower levels of NF-kB during mucositis development and healing. The preventive and combined protocols were associated with higher NF-kB levels at day 5; however, the therapeutic group had higher levels at days 10 and 15. These findings suggest that the preventive and/or therapeutic PBM protocols reduced the severity of oral mucositis by activating the NF-kB pathway.

Laser phototherapy accelerates oral keratinocyte migration through the modulation of the mammalian target of rapamycin signaling pathway

Keratinocytes play a central role in wound healing by responding to tissue injury through the activation of cellular proliferation and migration. Current clinical evidence suggests that the laser phototherapy (LPT) accelerates wound healing in a variety of oral diseases; however, the molecular mechanisms involved in response to LPT are not fully understood. Oral keratinocytes (NOK-SI) maintained under nutritional-deficit culture medium (2% fetal bovine serum) were irradiated with InGaAlP laser (660 nm; 40 mW; 0.04  cm2 spot size) in punctual and contact modes. The energy densities used were 4 and 20  J/cm2 corresponding to 4 and 20 s of exposure times and 0.16 and 0.8 J of energy per point, respectively. Three sessions of irradiations were applied with 6-h intervals. Further, the impact of LPT over cellular migration, proliferation, and activation of the mammalian target of rapamycin (mTOR) pathway, known to play a major role in epithelial migration and wound healing, was analyzed. Compared with control cells, the LPT-treated cells showed accelerated cellular migration without any changes in proliferation. Furthermore, LPT resulted in an increase in the phospho-S6 ribosomal protein, indicating activation of the mTOR signaling pathway. Collectively, these findings suggest that the LPT activates mTOR signaling pathway, promotes epithelial cell migration, and accelerates healing of oral mucosa.

Multiple metastases of malignant melanoma in the head and neck: a case report and literature review

Malignant melanoma (MM) with multiple metastases (including the oral mucosa) is an extremely rare condition that is difficult to manage due to its complexity. This article presents the case of a 27-year-old man who first developed MM on the scalp, which subsequently metastasized to the mandible, parotid gland, infratemporal fossa, and the cervical regions of the larynx, kidneys, liver, and lungs. The findings of the present case report are compared with 31 other cases published in the English literature. Multiple metastases of MMs in the head and neck region are rare and generally are associated with a poor prognosis. In such cases, dentists play a role in the diagnosis, prevention, and treatment of sequelae stemming from oncologic treatment, with the aim of improving the patient's quality of life.

Cytogenetic abnormalities in exfoliated oral mucosal cells and their association with oral cancer

OBJECTIVE

To assess cytogenetic abnormalities through quantification of micronuclei, broken eggs, and karyorrhexis, in cells from normal oral mucosa of individuals exposed to carcinogens (alcohol and tobacco) and adjacent to leukoplakias and squamous cell carcinomas.

STUDY DESIGN

The sample was composed of 40 subjects aged > 30 years, divided into four groups: control, alcohol/tobacco, leukoplakia, and squamous cell carcinoma. For control and alcohol/tobacco groups, cells were collected from lower lip, tongue border, and floor of the mouth. For leukoplakia and squamous cell carcinoma groups, mucosa contralateral and adjacent to the lesions were analyzed. Cytologic smears were stained with the Feulgen reaction. A blind observer analyzed 1,000 cells per slide to quantify micronuclei, broken eggs, and karyorrhexis.

RESULTS

The leukoplakia group showed an increased number of micronuclei compared to controls (p = 0.0016) and the alcohol/tobacco group (p = 0.0048) and also increased broken eggs compared to the alcohol/tobacco group (p = 0.0172). Similarly, the carcinoma group presented more micronuclei compared to controls (p = 0.0462) and more broken eggs compared to the alcohol/tobacco group (p = 0.0104).

CONCLUSION

The assessment of cytogenetic abnormalities micronuclei and broken eggs may be useful for monitoring individuals exposed to risk factors for developing oral cancer.