Feasibility of mapping breast cancer with supine breast MRI in patients scheduled for oncoplastic surgery.

OBJECTIVES: To prospectively determine the feasibility of preoperative supine breast MRI in breast cancer patients scheduled for oncoplastic breast-conserving surgery. METHODS: In addition to a diagnostic prone breast MRI, a supplementary supine MRI was performed with the patient in the surgical position including skin markers. Tumours' locations were ink-marked on the skin according to findings obtained from supine MRI. Changes in tumours' largest diameter and locations between prone and supine MRI were measured and compared to histology. Nipple-to-tumour and tumour-to-chest wall distances were also measured. Tumours and suspicious areas were surgically removed according to skin ink-markings. The differences between MRI measurements with reference to histopathology were evaluated with the paired-sample t test. RESULTS: Fourteen consecutive patients, 15 breasts and 27 lesions were analysed. Compared to histology, prone MRI overestimated tumour size by 47.1% (p = 0.01) and supine MRI by 14.5% (p = 0.259). In supine MRI, lesions' mean diameters and areas were smaller compared to prone MRI (- 20.9%, p = 0.009 and - 38.3%, p = 0.016, respectively). This difference in diameter was more pronounced in non-mass lesions (- 31.2%, p = 0.031) compared to mass lesions (- 9.2%, p = 0.009). Tumours' mean distance from chest wall diminished by 69.4% (p < 0.001) and from nipple by 18.2% (p < 0.001). Free microscopic margins were achieved in first operation in all patients. CONCLUSIONS: Supine MRI in the surgical position is feasible and useful in the precise localisation of prone MRI-detected lesions and provides a helpful tool to implement in surgery. Supine MRI more accurately determines tumours' size and location and might have an important role to diminish overestimations. KEY POINTS: • Breath-hold supine breast MRI is feasible using commercially available coils and sequences. • Size and area of lesions on MRI were consistently smaller when measured from the supine position as compared to the prone position. • Supine breast MRI is useful in the precise preoperative localisation of prone MRI-detected lesions. •.

Efficacy and safety of myocardial gene transfer of adenovirus, adeno-associated virus and lentivirus vectors in the mouse heart.

Gene therapy is a promising new treatment option for cardiac diseases. For finding the most suitable and safe vector for cardiac gene transfer, we delivered adenovirus (AdV), adeno-associated virus (AAV) and lentivirus (LeV) vectors into the mouse heart with sophisticated closed-chest echocardiography-guided intramyocardial injection method for comparing them with regards to transduction efficiency, myocardial damage, effects on the left ventricular function and electrocardiography (ECG). AdV had the highest transduction efficiency in cardiomyocytes followed by AAV2 and AAV9, and the lowest efficiency was seen with LeV. The local myocardial inflammation and fibrosis in the left ventricle (LV) was proportional to transduction efficiency. AdV caused LV dilatation and systolic dysfunction. Neither of the locally injected AAV serotypes impaired the LV systolic function, but AAV9 caused diastolic dysfunction to some extent. LeV did not affect the cardiac function. We also studied systemic delivery of AAV9, which led to transduction of cardiomyocytes throughout the myocardium. However, also diffuse fibrosis was present leading to significantly impaired LV systolic and diastolic function and pathological ECG changes. Compared with widely used AdV vector, AAV2, AAV9 and LeV were less effective in transducing cardiomyocytes but also less harmful. Local administration of AAV9 was safer and more efficient compared with systemic administration.

Strong claudin 5 expression is a poor prognostic sign in pancreatic adenocarcinoma.

We investigated the expression of claudin 5 in 88 ductal adenocarcinomas of the pancreas. The results were correlated with patient prognosis, with claudin 5 expression in blood vessels, with the expression level of bcl2 and bax and with apoptosis. Claudin 5 expression was detected in 24 (38%) cases. It was not associated with tumour size or spread, but strong claudin 5 expression correlated with a worse survival (p = 0.005). Claudin 5 also associated with a higher extent of apoptosis and greater expression of bax protein. In the tumour vasculature, some vessels displayed a loss of claudin 5 expression. The presence of this loss was associated with tumour grade and the presence of nodal metastases (p = 0.02, p = 0.022, respectively). These results indicate that claudin 5 is upregulated in a proportion of pancreatic ductal adenocarcinomas. The association of strong claudin 5 expression with a worse survival is in line with some earlier reports indicating that this protein is involved with increased locomotion and more aggressive spread of carcinomas. The association of claudin 5 with apoptosis and bax might be due to stronger cellular kinetics found in such tumours. The loss of claudin 5 expression in the tumour vasculature points to a leaky vessel type; this might also ease the access of tumours to vessels and be reflected in its association with the presence of nodal metastases.

Secondary squamous cell prostate cancer after prostate brachytherapy treatment.

This report describes the case of a patient with prostate cancerat the age of 59 years, who was treated by interstitial prostate brachytherapy with iodine-125 seeds. Ten years later, he developed a probable secondary squamous cell cancer in his prostate.

Indications of hepatic and cardiac toxicity caused by subchronic Tricholoma flavovirens consumption.

The yellow tricholoma (Tricholoma flavovirens or Tricholoma equestre) is a wild mushroom species that was previously considered edible and tasty. Recently, it caused several cases of delayed rhabdomyolysis in humans and elevated serum creatine kinase (CK) activities in laboratory mice (Mus musculus) in a dose-response study. The present study continued to examine the effects of prolonged T. flavovirens consumption at 12 g freshly frozen mushroom kg(-1)d(-1) on the plasma clinical chemistry and organ histology of mice. The plasma CK and CK-MB activities and the plasma bilirubin concentrations were higher in the exposed mice than in the controls. In addition, pericardial lymphocyte infiltrates were present in the mice that had consumed the mushroom. The results indicate myo-, cardio- and hepatotoxic effects of T. flavovirens.

Expression of Ki-67, cyclin D1 and apoptosis markers correlated with survival in prostate cancer patients treated by radical prostatectomy.

OBJECTIVE: The study was designed to analyse the prognostic value of proliferation markers Ki-67 and cyclin D1 and apoptosis in prostate cancer (PC) patients treated by radical prostatectomy. PATIENTS AND METHODS: Two hundred and eleven patients treated by radical prostatectomy for localised prostate cancer were clinically followed up for a mean of 7.3 years. The primary histopathological specimens were re-analysed to ensure uniform histoplthological grading and pT classification. A tissue microarray construction (TMA) was used in immunohistochemisty to assess the expression of Ki-67, cyclin D1 and the apoptosis marker Tag. The results were analysed with light microscopy and the findings were compared to standard histology, pT and clinical follow-up data. RESULTS: The co-expression of Ki-67 and cyclin Dl (p=0.05) was common. High fraction of Ki-67 positive cells and a high fraction of apoptotic cells were often present in same tumours (p=0.05). High apoptotic rate was related to positive surgical margin status (p=0.047). Low expression of Ki-67 was related to a low Gleason score (p<0.001), an absence of either capsule penetration (p = 0.029) or perineural invasion (p=0.004). High expression of cyclin Dl was related to perineural growth (p=0.039). Prostate specific antigen (PSA) recurrence-free survival (RFS) was predicted by Gleason grade (p<0.001) and capsule invasion (p=0.006). High expression of Ki-67 (p=0.03), as well as high apoptotic rate (p=0.04) were related to a high risk of cancer death. In multivariate analysis the seminal vesicle invasion was the only independent predictor of cancer death (p = 0.01). CONCLUSION: The expression of Ki-67, cyclin D1 and a high apoptotic rate are related to a malignant phenotype in prostate cancer, but their prognostic value is inferior to standard histological prognostic factors.

Protein p62 common in invaginations in benign meningiomas--a possible predictor of malignancy.

OBJECTIVE: It is known that p62 is a cytosolic conserved protein that binds non-covalently to ubiquitin. Expression of p62 has been seen in inclusions in neoplasias like hepatocellular and breast carcinomas but also in neuronal inclusions of degenerative brain disorders. Dysfunction of ubiquitin system leads to presence of p53 in cells suggested to be a predictor of future recurrence of meningioma. MATERIAL: The study material included 45 benign meningiomas of postmenopausal women operated in Kuopio University Hospital between 1994 and 2002. METHODS: Patterns of p62 immunopositivity in meningiomas was evaluated and the results were correlated to clinical and histological parameters. RESULTS: Constant p62 labeling in at least each field measuring 1 mm in diameter was detected consisting of 5 different patterns. The most common labeling was seen in nuclear invaginations either as grains or homogenous labeling, followed by Marinesco like nuclear inclusions or rode like inclusions outside the invagination. In some cases cytoplasmic granular staining was seen. No correlation between different p62 patterns or extent of p62 expression, histological subtypes or proliferation marker Ki-67 was noted. CONCLUSION: Our results indicate that in the benign not recurrent meningiomas, signs of functioning proteosomal system, can be detected using the p62 labeling. The function of proteosomal system in malignant and specifically invasive meningiomas needs to be further elucidated.

Reduced alpha- and beta-catenin expression predicts shortened survival in local prostate cancer.

UNLABELLED: The aim of this study was to determine the prognostic value of alpha- and beta-catenin expressions in local prostate cancer (PC). MATERIALS AND METHODS: One hundred and eighty-one PC patients treated with radical prostatectomy were followed-up for a mean of 7.3 years. The alpha- and beta-catenin expression were analysed by immunohistochemistry TMT (tissue microarray technique) and light microscopy. RESULTS: Strong a-catenin expression was related to low Gleason grade (p < 0.001), cancer-free seminal vesicles (p = 0.04) and low preoperative PSA (p = 0.02). Strong beta-catenin expression was related to low Gleason grade (p < 0.001) and cancer-free seminal vesicle status (p = 0.03). Absence of nuclear beta-catenin expression was related to local disease (pT1-T2) (p = 0.05). alpha-catenin (p = 0.06), beta-catenin (p = 0.05), Gleason grade (p = 0.03) and capsular invasion (p = 0.01) were related to PSA recurrence in patients who reached PSA zero postoperatively. PSA recurrence-free survival (RFS) was significantly related to Gleason grade (p < 0.001), capsule invasion (p = 0.01), perineural growth (p = 0.05) and preoperative PSA (p = 0.05). In Cox's analysis, independent predictors of PSA RFS were Gleason grade (p < 0.001) and capsular invasion (p = 0.006). Low expressions of alpha- (p = 0.06) and beta-catenin (p = 0.05) were related to shortened PSA RFS. Survival was related to low alpha- (p = 0.011) and beta-catenin (p = 0.016) expressions. Independent predictors of shortened survival were seminal vesicle invasion (p = 0.016) and low alpha-catenin expression (p = 0.049). CONCLUSION: Reduced alpha- or beta-catenin expressions are related to malignant phenotype in local prostate cancer and predict PSA failure as well as shortened survival.

Collagen IV and tenascin immunoreactivity as prognostic determinant in benign and malignant salivary gland tumours.

The expression of collagen IV and tenascin was studied in a series of 219 salivary gland tumours with special emphasis on the prognostic significance of these extracellular matrix constituents. Continuous and uninterrupted staining of the basal membrane with collagen IV antibody was found in 62% (64/103) of the carcinomas and in 92% (107/116) of the benign tumours, the staining being weak and interrupted in 38% (39/103) and 8% (9/116) of cases, respectively. Weak immunoreactivity for collagen IV was significantly (p = 0.05) associated with recurrences of the malignant salivary gland tumours. Intense collagen IV staining of the basal membrane was more frequent (35.9%) in patients who were alive, as compared with that (19.4%) of the patients who died of salivary gland cancer (p = 0.03). Similarly, the intactness of the basal membrane was directly related to patient survival. In benign tumours, no such differences were found. In multivariate analysis, collagen IV immunoreactivity was related to the age of the patients (p = 0.007) and to tumour diameter > 4.0 cm (p = 0.005). Intense tenascin immunoreactivity was found in 45% (46/103) of the carcinomas and in 43% (50/116) of the benign tumours, 55% (57/103) and 57% (66/116) of the cases being entirely tenascin-negative, respectively. Tenascin immunoreactivity was not related to the clinical behaviour of malignant salivary gland tumours. In benign tumours, an intense staining for tenascin was a determinant of recurrent disease (p = 0.05). In multivariate analysis, tenascin immunoreactivity was intimately associated with erbB-2 positivity (p = 0.03) and weak staining of collagen IV (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Nuclear Nrf2 expression is related to a poor survival in pancreatic adenocarcinoma.

The aim of this study was to investigate the expression of Nrf2, sulfiredoxin and DJ1 in pancreatic cancer. The expression of Nrf2, sulfiredoxin and DJ1 was studied immunohistochemically in a large set of pancreatic adenocarcinomas consisting of 103 cases. Eighty six percent of the cases showed cytoplasmic Nrf2 and 24% nuclear Nrf2 positivity. Sulfiredoxin positivity was observed in 54% and DJ1 positivity in all cases. Nuclear Nrf2 positivity had an association with sulfiredoxin (p=0.019) and was associated with a poor survival (p=0.010). Stage IV tumors tended to have a more nuclear Nrf2 expression (p=0.080). DJ1 expression was more often found in well-differentiated tumors (p=0.012), and DJ1 expression was associated with better survival (p=0.020). According to the results, nuclear Nrf2 expression predicts a worse survival in pancreatic adenocarcinoma, which is in keeping with its protection of cells against oxidative or xenobiotic stress. In accordance with Nrf2's regulation of the synthesis of sulfiredoxin, there was an association between them (p=0.019). DJ1 had no association with Nrf2, and its expression predicted a better survival of patients.

Expression of claudins 7 and 18 in pancreatic ductal adenocarcinoma: association with features of differentiation.

AIM: This study was undertaken to evaluate the expression of claudins 7 and 18 in pancreatic ductal adenocarcinoma. METHODS AND RESULTS: Material tested included 111 operated samples and 47 additional biopsy samples consisting of 26 cases of pancreatitis, 3 cases of pancreatic intraepithelial neoplasia and 18 ductal adenocarcinomas. Samples were stained with antibodies to claudins 7 and 18 and analysed for membranous and cytoplasmic expression. Membrane bound claudin 7 and 18 expression was detected in 62 of 105 (59%) and 78 of 111 (70%) cases, respectively. Membrane bound claudin 7 and 18 were associated with large or intermediate neoplastic ducts (p=0.01, p=0.002, respectively). Well differentiated pancreatic adenocarcinomas displayed more cases with membrane bound claudin 7 or 18 immunopositivity (p=0.003, p=0.03, respectively). All pancreatic intraepithelial neoplasias studied expressed membrane bound claudin 18. Membrane bound claudin 7 or 18 positivity was not associated with survival (p=0.17, p=0.98). In the biopsy cases membrane bound claudin 18 had 100% specificity and 51% sensitivity for a tumour marker. CONCLUSION: Claudin 7 and 18 expression is related to gland size of neoplastic cells and is especially found in tumours with intermediate and large ducts and well differentiated tumours. Membrane bound claudin 18, when present, is a useful marker for diagnosis of pancreatic cancer. Claudins 7 and 18 were not associated with patient survival or spread of tumours.

8-hydroxydeguanosine and nitrotyrosine are prognostic factors in urinary bladder carcinoma.

Oxidative stress markers and peroxiredoxins are connected to cancer. A large set of urinary bladder carcinomas were studied for the expression of nitrotyrosine and 8-hydroxydeguanosine (8OHdG), two markers indicating oxidative damage. Serum and urine 8-OHdG were assessed in a subset of patients. We also analysed immunohisto-chemically the expression of nrf2, keap1, all six peroxiredoxins (prx) and thioredoxin (trx) in these tumors. 15 % of the cases showed 8OHdG and 36 % nitrotyrosine positivity. Expression of nitrotyrosine and 8OHdG associated with a poor prognosis (p=0.050, p=0.011, respectively). Peroxiredoxin positivity ranged from 39 % to 84 % lowest expression being for prx 4 and highest for prx 3. Prx 4 expression associated with a poor prognosis (p=0.025) with high grade (p=0.044) and larger tumors (p=0.023). Cytoplasmic trx positivity was seen in 91 % and nuclear in 59 % of tumors. Nuclear and cytoplasmic trx associated with each other (p<0.001), and nuclear trx associated with prx 6 (p=0.001), prx 2 (p<0.001), and prx 5 (p<0.001). 8OHdG associated with nuclear trx positivity (p=0.002), inversely with prx 1 (p=0.025) and with keap1 (p=0.020). Nuclear nrf2 was associated with nitrotyrosine (p=0.042). The results show that the amount of oxidative stress in urinary bladder tumors affects the prognosis of the patients. Of antioxidative enzymes, prx4 associated with an unfavourable prognosis. Selective inhibition of prx4 expression might then be one additional option of treatment of bladder cancer.

Vasopressor agents after experimental brain death: effects of dopamine and vasopressin on vitality of the small gut.

BACKGROUND: Both congenital and acquired short bowel syndrome frequently leads to the necessity for long-term parenteral nutrition, which in turn may lead to any of several complications or death. Transplantation of the small bowel from brain-dead organ donors has been successfully performed over the last years. However, systemic blood pressure and blood perfusion to the splanchnic area decrease rapidly after brain death, which comprises the vitality of the small bowel. OBJECTIVE: To evaluate the differences between dopamine and low-dose vasopressin on perfusion and vitality of the small bowel after brain death. METHODS: Fifteen pigs were randomized into 3 groups: vasopressin (n = 6), dopamine (n = 6), or control (n = 3). Brain death was induced via stepwise filling of an epidural balloon. When the hypotensive phase was achieved, vasopressin, maximum dose of 0.04 IU/kg/h, or dopamine, maximum dose of 20 µg/kg/min, was administered for 5 hours with the objective of increasing mean arterial blood pressure by 15 mm Hg. RESULTS: Target blood pressure was achieved in the vasopressin group but not the dopamine group. Vasopressin reduced cardiac output, superior mesenteric artery (SMA) blood flow and oxygen delivery, and systemic oxygen delivery and consumption, and increased oxygen extraction. Dopamine increased SMA blood flow, and had no effect on systemic oxygen delivery or consumption. CONCLUSIONS: Vasopressin reversed hypotension but compromised both the systemic and SMA blood flow. Vasopressin was associated with inadequate oxygen delivery, estimated from decreased oxygen delivery and increased oxygen extraction. These adverse effects were not observed with dopamine.

Learning curve for add-on stereotactic core needle breast biopsy.

PURPOSE: To evaluate the learning curve for an add-on 14 G stereotactic core needle biopsy (SCNB). MATERIAL AND METHODS: A total of 231 non-palpable breast lesions that had undergone add-on SCNB were evaluated in this prospective study. Five radiologists performed their first three biopsies under supervision. Subsequent, independently performed, biopsies were also evaluated. The samples were collected in three different containers: the first sample in container A, the second and third samples in container B, and subsequent samples in container C (available for four radiologists from the first biopsy on). Technically successful biopsies and false-negative rate in three container combinations (A, A+B, A+B+C) were reported as a function of operator experience. RESULTS: Technically unsuccessful biopsies occurred significantly more often in microcalcifications than in masses (14.9% versus 3.8%; P=0.04). For microcalcifications, the rate of successful biopsies was 75% (18/24) for the first 5 biopsies and 87.8% (79/90) for the subsequent biopsies (P=0.335); rates for the masses were 95.7% (22/23) and 96.3% (79/82) (P=1.0), respectively. A tendency was noted for the false-negative rate to be higher for the first five biopsies in three container combinations than in subsequent cases. CONCLUSION: Our results support the existence of a learning curve, especially in the biopsy of microcalcifications. More than three mentor-guided biopsies are needed.

No Epstein Barr and cytomegalovirus DNA found in salivary gland tumours.

A series of 219 (106 malignant and 113 benign) salivary gland tumours was investigated by in situ hybridisation (ISH) to detect Epstein-Barr-virus (EBV) and cytomegalovirus (CMV) DNA. Normal salivary gland did not show hybridisation signals for these viruses. Tumours presenting hybridisation signals in ductal and myoepithelial cells and 17 Warthin's tumours were further studied by PCR, but none of these tumours contained EBV or CMV DNA. Our series did not contain lymphoepithelial carcinomas, which are EBV-associated tumours. The results suggest that factors other than EBV or CMV are involved in carcinogenesis of primary salivary gland tumours.

c-erbB-2 oncogene expression in salivary gland tumours.

Prompted by recent findings on the amplification of c-erbB-2 (HER-2, neu) oncogene in salivary gland tumours, the present study was conducted to analyse the expression of c-erbB-2 in both benign and malignant salivary gland tumours, with special emphasis on its prognostic significance and relevance to clinical data. A series of 219 salivary gland tumours (with pertinent clinical data), including 103 malignant and 116 benign tumours, were analysed immunohistochemically using a monoclonal antibody to c-erbB-2 protein. Smoking was not a risk factor for malignant tumours, smokers being equally represented in both groups: 18.4 and 21.6% in malignant and benign series, respectively. Multi-variate analysis of the extensive clinical data did not disclose any other risk factors either. Cellular membrane staining for c-erbB-2 was present in 36 (35.0%) carcinomas and 41 (35.3%) benign tumours. Among the malignant tumours, c-erbB-2 expression was most frequent in adenoid cystic carcinomas (57.7%) followed by adenocarcinomas (39.3%). Among the benign tumours, 47% of Warthin's tumours and 33.3% of the pleomorphic adenomas showed staining for c-erbB-2. The highest prevalence of c-erbB-2 immunoreactivity was seen in adenocarcinomas of the parotid gland (81.8%), followed by undifferentiated carcinomas (75%) and adenoid cystic carcinomas (73.3%) in that location. Age at diagnosis, number of recurrences, analysis as well as time to relapse or metastases were similar in c-erbB-2-positive and -negative malignant tumours. Also mortality in c-erbB-2-positive and -negative salivary gland cancers was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunocompetent cells in benign and malignant salivary gland tumors.

IgA-, IgG, and IgM-producing plasma cells as well as 3- and T-lymphocytes were immunophenotyped and quantitated in a series of 216 benign and malignant salivary gland tumors, with special emphasis placed on the clinical behavior of the tumors. Highest number of plasma cells were found in mucoepidermoid carcinomas, where IgG-plasma cells were the sole Ig-class secreted. No IgA-immunoreactivity was found in adenoid cystic, undifferentiated, acinic cell, carcinoma in pleomorphic adenoma, and mucoepidermoid carcinomas. In squamous cell carcinomas, the number of IgM-plasma cells was higher than that in other salivary gland tumors. Basal cell adenomas contained only IgM-positive plasma cells. In logistic regression analysis, IgG- and IgM-producing plasma cells in malignant salivary gland tumors were related to an increased tumor diameter (p = 0.022 and 0.046, respectively). In benign tumors, neither clinical nor prognostic value could be attributed to the distribution of plasma cells. T-cells and B-cells were present in 63.9% and 33.8% of all tumors, found in 63.8% and 26.7% (p = 0.0048) of the benign tumors, and in 64.1% and 41.7% (not significant) of the malignant tumors, respectively. The presence of T- of B-lymphocytes was of no prognostic significance in malignant tumors. In benign tumors, however, the mean age of the patients was significantly higher (p = 0.010) and the mean time to recurrence significantly shorter (p = 0.018) in patients with tumors containing T-cells than in those devoid of these cells. In conclusion, the cell-mediated immunity (T-cells and their subsets) seems to play a more important role in pathogenesis and prognostication of salivary gland neoplasms than do the cells of the B-cell lineage, and, clearly, further studies are needed to elucidate these issues.

Epstein-Barr virus involvement in salivary gland lesions associated with Sjögren's syndrome.

Recently, Epstein-Barr virus (EBV) has gained increasing attention as a potential causative agent of Sjögren's syndrome, which is an autoimmune disorder characterized by lymphocytic infiltration of salivary and lacrimal glands. To determine the association between Sjögren's syndrome and EBV, we re-evaluated the salivary gland biopsies from patients previously diagnosed to have Sjögren's syndrome. Altogether, 20 cases of Sjögren's syndrome were reviewed from the files of the University Central Hospital since 1975. After re-evaluation of these biopsies, however, 11 patients did not fulfil the current criteria of Sjögren's syndrome, but were diagnosed as having chronic sialadenitis. All biopsies were processed for in situ hybridization (ISH) and polymerase chain reaction (PCR) to detect EBV DNA. With ISH, all samples were negative for EBV DNA. With PCR, however, 9 biopsies proved to be positive for EBV. 3 additional positive cases were found when the amplification product was dot-blotted and hybridized with EBV DNA probe. 10 of the EBV-positive salivary gland biopsies showed the histological features of chronic sialadenitis and only 2 cases were classified as having Sjögren's syndrome. On the basis of the present results, the association between EBV and Sjögren's syndrome remains doubtful.

Expression and mutations of p53 in salivary gland tumours.

A series of 219 salivary gland tumours (103 carcinomas and 116 benign tumours) were analysed for p53 protein expression using immunohistochemistry, and for mutations in p53 gene using non-radioactive single strand conformation polymorphism (SSCP). p53 expression was present in 36% (42/116) of the benign tumours and in 54% (56/103) of the carcinomas. The highest prevalence of p53 expression was found in adenoid cystic carcinomas (69%), followed by mucoepidermoid carcinomas (67%). Of the benign tumours, pleomorphic adenomas showed the highest prevalence of p53 positivity (41%). In malignant tumours, expression of p53 bore no correlation to local recurrence, metastatic disease or survival of the patients. Exons 5 through 9 were analysed and four mutations were found in 20 cases of p53-immunopositive tumours and two in 20 p53-negative tumours. Each of the exons 5, 6 and 8/9 had two mutations, whereas no mutations were detected in exon 7.