Specific p53 immunostaining patterns are associated with smoking habits in patients with oral squamous cell carcinomas

AIMS

To identify immunostaining patterns that are predictive for p53 mutations and to investigate whether p53 mutations are associated with established risk factors for oral squamous cell carcinoma (OSCC).

METHODS

Fifty five OSCCs were investigated for p53 protein expression by immunohistochemistry (IHC). Ten of these cases, including five p53 immunopositive and five p53 immunonegative cases, were subjected to microdissection of representative tumour areas followed by sequence analysis for the detection of TP53 mutations.

RESULTS

Paired IHC and sequence analysis revealed that p53 immunoexpression in more than 25% of tumour cells was indicative of TP53 mutations, whereas p53 immunonegativity was not informative. Therefore, for p53 immunohistochemical interpretation, p53 immunonegative cases were excluded from the analysis and the cut off value for p53 immunoexpression was set at 25%. Of the OSCCs showing any p53 immunoexpression, 64% revealed staining in more than 25% of the tumour cells. p53 immunoexpression in more than 25% of the neoplastic cells was significantly associated with smoking but not with alcohol consumption. No significant association with smoking habits was found when OSCCs were dichotomised into p53 immunonegative and p53 immunopositive.

CONCLUSIONS

In OSCCs the following conclusions can be made: (1) p53 immunonegativity is not informative for TP53 mutations; (2) 25% p53 immunopositive cells appears to be a good cut off value to predict TP53 mutations; (3) p53 immunostaining patterns that appeared to be predictive for TP53 mutations were associated with the smoking habits of the patients.

Lack of MHC class I surface expression on neoplastic cells and poor activation of the secretory pathway of cytotoxic cells in oral squamous cell carcinomas

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells use the secretory pathway of perforin/granzymes to kill their target cells. In contrast to NK cells, CTL responses are MHC class I restricted. In this study we analysed the relative activation of CTL and NK cells in relation with MHC class I expression on oral squamous cell carcinomas (OSCCs). MHC class I expression was investigated in 47 OSCCs by immunohistochemistry using HCA2, HC10 and beta2-m antibodies. The presence of CTLs, NK cells, and its activation, was investigated in 21 of these OSCCs using respectively, CD8, CD57 and GrB7 antibodies. The Q-Prodit measuring system was used for quantification of cytotoxic cells. All OSCCs showed weak or absent staining of beta2-m on the cell surface. The absence of beta2-m was significantly associated with absent expression of MHC class I heavy chain as detected by HC10 antibody (P = 0.004). In tumour infiltrates CTLs always outnumbered NK cells, as reflected by the ratio CD57/CD8 being always inferior to one (mean: 0.19; SD: 0.15). The proportion of activated cytotoxic cells as detected by granzyme B expression was generally low (mean: 8.6%; SD 8.9). A clear correlation between MHC class I expression and the relative proportion of NK cells/CTLs was not found. This study shows that the majority of OSCCs show weak or absent expression of MHC class I molecules on the cell surface, possibly due to alterations in the normal beta2-m pathway. The low proportion of granzyme B-positive CTLs/NK cells indicates that the secretory pathway of cytotoxicity is poor in these patients. The lack of correlation between MHC class I expression and CTL/NK cell activation as detected by granzyme-B expression suggests that, next to poor antigen presentation, also local factors seem to determine the final outcome of the cytotoxic immune response.

Langerhans' cell histiocytosis of the jaw bones. Report of 11 cases

Eleven cases of Langerhans' cell histiocytosis of the jaw bones are reported. The clinical and radiographic features are described, and the role of the dentist in the diagnosis and management of this disorder is discussed.

Results of the surgical management and histopathological evaluation of 88 parotid gland Warthin's tumours

With the introduction of parotidectomy after identification of the facial nerve the recurrence rates for benign tumours has declined rapidly. Subsequently, attention was focused on other sequelae of parotid surgery. To reduce the specific surgical morbidity, several modifications of parotidectomy have been implemented. This study compares the results of the different surgical techniques with regard to the histopathological findings and recurrence rate for Warthin's tumour of the parotid gland. Eighty-eight primary surgical parotid procedures were performed on 85 patients for a Warthin's tumour. The surgical procedures included 52 'partial' superficial parotidectomies, 22 'standard' superficial parotidectomies, 12 partial superficial/deep lobe parotidectomies, and two 'selective' deep lobe parotidectomies. No patient developed a recurrence or experienced permanent facial nerve paresis/paralysis, the median follow-up being 93 months. Histopathological examination revealed a multifocal origin in 23% (20/88) of the surgical specimens. Partial parotidectomy is an effective treatment for Warthin's tumour. There is no need for extended follow-up.

Prevalence of Epstein-Barr virus in oral squamous cell carcinomas, premalignant lesions and normal mucosa--a study using the polymerase chain reaction

Epstein-Barr virus (EBV) prevalence was assessed in 12 clinically normal oral mucosas, nine premalignant lesions, 36 oral squamous cell carcinomas (OSCCs) and a human papillomavirus (HPV) 16 positive cell line, derived from an OSCC studied. The polymerase chain reaction (PCR) with two pairs of primers with different sensitivities was used. With primers specific for the BamHIW repeat, EBV was found in 100% of OSCCs, in 77.8% of premalignant lesions and in 8.3% of clinically normal oral mucosas (P = 0.0001). Using primers specific for the single copy BNLF-1 gene, EBV was detected in 50% of OSCC and in none of the premalignant lesions. No statistically significant associations could be established among EBV presence and clinico-pathological data of OSCC. The cell line derived from an HPV/EBV-positive carcinoma did not reveal EBV DNA. The higher prevalence of EBV in OSCCs and premalignant lesions may be due to increased EBV shedding, possibly due to associated immunodepression in these patients, rather than its clonal presence in the neoplastic cells.

Relationship of tobacco/alcohol use to p53 expression in patients with lingual squamous cell carcinomas

This study examined p53 expression immunocytochemically in 40 lingual squamous cell carcinomas from Dutch patients with known histories of smoking and/or drinking alcohol. 30% of neoplasms showed positive p53 reactivity, suggesting increased levels of p53 protein. No alcohol or tobacco risk factors were evident in 33.3% (4/12) of p53-positive neoplasms whereas only 7.1% (2/28) of p53-negative neoplasms showed an absence of these risk factors. 25% (3/12) of p53-positive neoplasms and 71.4% (20/28) of p53-negative neoplasms were found in patients who had been exposed to both alcohol and tobacco. A similar negative association with p53 reactivity was also found when either tobacco or alcohol were used in isolation. The results contrast with previous observations in head/neck and oral carcinomas and indicate that the association of alcohol/tobacco and p53 expression remains open to question.

Unusual behaviour of periapical cementous dysplasia

A case of periapical cementous dysplasia is reported that over the course of 12 years developed into a progressive bone lesion. The diagnostic and therapeutic aspects are discussed.

Oral hairy leukoplakia in HIV infection: a diagnostic pitfall

Twenty-nine human immunodeficiency virus (HIV)-infected patients with white, nonremovable lesions on the lateral border of the tongue, clinically suggestive of oral hairy leukoplakia (HL), were studied. In particular, the value of local antifungal therapy in establishing the diagnosis of HL was investigated. In 15 patients (52%) the lesions could be ultimately attributed to a candidal infection of the tongue. In 10 of the remaining 14 patients, a biopsy was obtained from lesions persisting after local antifungal treatment. In all biopsy specimens, the diagnosis of HL was confirmed by histopathologic examination and the demonstration of Epstein-Barr virus DNA by polymerase chain reaction, Southern blot hybridization, and DNA in situ hybridization. The present data confirm that the diagnosis of HL in HIV-infected patients cannot be reliably made on clinical criteria alone, but requires histopathologic confirmation including the demonstration of Epstein-Barr virus DNA, preferably by DNA in situ hybridization. However, with regard to the differential diagnosis of white, nonremovable lesions on the lateral border of the tongue in HIV-infected patients, the present study suggests that persistence of lesions after local antifungal therapy is highly suggestive of HL.

Parapharyngeal tumours: a review of 23 cases

The anatomy of the parapharyngeal space is described and experience with 23 patients with parapharyngeal tumours seen over a 10-year period is reported. Despite reaching a large size, these tumours may be relatively asymptomatic, or be discovered incidently. CT scan, MRI, arteriography and fine needle aspiration are useful in establishing a diagnosis. The most common histological type (13/23 patients) was pleomorphic adenoma and these tumours were managed by transoral removal if small, or a combined transoral-external approach if large. No patient required a mandibulotomy for access and no benign tumour recurred. The outcome was poor in the 5 patients with malignant tumours and a more radical approach, midline mandibulotomy, should be considered if malignancy is suspected.

Ewing's sarcoma of the mandible: report of a case

A case of Ewing's sarcoma located in the mandible of a 12-year-old boy is reported. The lesion presented as a rapidly growing soft tissue swelling of the face and was accompanied by low-grade fever, suggestive of an inflammatory disease.

Lingual thyroid. A clinical and postmortem study

3 patients with lingual thyroid are reported. In addition, 5 patients are described with hypothyroidism in whom functioning thyroid tissue was only present at the base of the tongue without any noticeable swelling. In a postmortem study of 120 tongues, not a single case of lingual thyroid was encountered. The preponderance of females among cases of congenital hypothyroidism and/or lingual thyroid is discussed.

Multiple primary tumours in oral cancer

In 210 cases of oral cancer, 38 (17.6%) second primary tumours were found. Males had a higher chance of developing a second primary than females (21.4% versus 12%). The difference was not statistically significant (p = 0.11). When the index tumour was in the lower part of the oral cavity (floor of mouth, retromolar trigone, inferior alveolar process), a higher rate of second primaries was found than in cancer of the rest of the oral cavity (tongue, buccal mucosa and palate) (26.6% versus 11.5%). In male patients, this difference was statistically significant (p less than 0.05). 4 tumours were synchronous. In those 4 patients, panendoscopy would not have contributed to an earlier diagnosis. Routine panendoscopy in oral cancer therefore seems not valid.

Squamous cell carcinoma arising in the lining of odontogenic cysts. Report of 5 cases

The lining of odontogenic cysts seldom gives rise to the development of a carcinoma. In a review of the literature by Gardner in 1975, 25 cases were accepted as such. In the present paper, 5 new cases are reported. These cases were encountered during a 14-year-period in which 292 oral carcinomas were registered, emphasizing the rarity of carcinomas arising from odontogenic cysts.

Hyperbaric oxygen treatment of chronic osteomyelitis of the jaws

A review of the literature on treatment of chronic osteomyelitis of the jaws shows that hyperbaric oxygen is often recommended as an adjunct in treatment of this disease. Definite criteria to indicate this treatment and to evaluate the results have not been reported. The results of hyperbaric oxygen treatment of chronic osteomyelitis of the jaws in 16 patients are presented. In contrast to the good results reported in the literature, only 7 of our patients could be considered as cured. The reasons for this discrepancy are discussed. Our results, as well as the data from the literature, indicate that a combined antibiotic and surgical approach is the treatment of choice in chronic suppurative osteomyelitis. However, in chronic diffuse sclerosing osteomyelitis and in patients in whom decortication and antibiotic therapy have failed, hyperbaric oxygen treatment in combination with antibiotics and surgery seems to be indicated.