Intraductal Carcinoma: The Carcinoma In Situ of the Salivary Gland

Intraductal carcinoma of the salivary gland (IDC) is a rare in situ neoplasm of the salivary gland with similar features to the ductal carcinoma in situ of the breast. This report aims to present the clinical presentation and histological features of IDC. The authors present a 90-year-old gentleman with an indurated and painless tumor within the right parotid. Preoperative diagnostics, including fine needle aspiration cytology, ultrasound scan, and magnetic resonance imaging, were suggestive of Warthin tumor. The patient is disease free within the follow-up period of 33 months. Intraductal carcinoma is an indolent phenotype with only a few reported cases with nodal metastases, and to the best of our knowledge, no cases have been reported with distant metastases. Complete surgical excision is recommended to prevent a recurrence. The knowledge of this underreported salivary gland malignancy is important to prevent misdiagnosis and insufficient treatment.

Cutaneous head and neck SCCs and risk of nodal metastasis - UK experience

AIM

To identify the risk of developing metastases to regional nodes in patients with cutaneous squamous cell carcinomas (CSCCs) of the head and neck.

METHODS

A retrospective study of patients with CSCC treated with surgical excision alone between 2000 and 2002 was performed. Demographic details of the patients, the site, size, differentiation, depth of invasion, clearance of surgical margins, and the presence of perineural or lymphovascular invasion of the lesion were documented. During the follow up period, patients with regional metastases were identified. The site of the metastasis and the time after the primary resection were documented and statistical analysis was performed using Chi-square and logistic regression analysis.

RESULTS

One hundered and ninety-four patients were included and 218 CSCCs were excised in total during the period of 3 years. The scalp was the most common site of skin lesion, followed by the ear. The incidence of regional metastatic disease was found to be 5.15%. The parotid gland was the most common area of regional metastasis. No metastases occurred after the first 2 years of follow up. The pinna, the poor differentiation and incomplete excision margins were found to be associated with regional metastasis independently, with odds ratio of 16, 21, and 2 respectively.

CONCLUSIONS

The rate of regional metastasis from CSCC remains low. The parotid gland was the most favoured metastatic site. Patients with poorly differentiated squamous cell carcinoma (SCC) located on the ear and incomplete excision margins were at the greatest risk for developing regional lymph node metastasis and require close follow up.

Lipomatous Lesions of the Parotid Gland

PURPOSE

Lipomatous lesions of the parotid gland are rare and seldom considered in the initial diagnosis of a parotid mass. We report our experience in the management of patients with lipomatous lesions affecting the parotid gland.

PATIENTS AND METHODS

Retrospective analysis of all parotidectomies performed for neoplastic lesions in the maxillofacial unit between 1975 and 2003 and patients with lipomatous lesions involving the parotid gland were identified; 638 parotidectomies were performed in this period on 629 patients in which 660 neoplasms were identified. Eight patients were found to have lipomatous lesions and form the basis of this study.

RESULTS

Lipomatous lesions accounted for only 1.3% of parotid tumors and occurred more frequently in males, at a ratio of 3 to 1. The most common presentation was that of a slowly enlarging, painless mass. Computed tomography scan was the most frequent imaging modality undertaken, and in 3 patients a diagnosis of a lipoma was made preoperatively. Seven patients underwent a superficial parotidectomy and 1 patient had a total conservative parotidectomy because of the deep lobe location of the mass. Five patients were found to have a focal lipoma and 3 patients had diffuse lipomatosis. There were no recurrences. Temporary facial nerve palsy and Frey's syndrome were the most frequent complications.

CONCLUSION

Lipomatous lesions accounted for only 1.3% of all parotid tumors. There were no specific distinguishing clinical features in our patients, and an accurate preoperative diagnosis was made in 3 patients based on imaging investigations. A well-circumscribed lipoma was more common than diffuse lipomatosis. Superficial parotidectomy was the treatment of choice and there were no recurrences in our series.

Does administration of isosorbide mononitrate affect cellular proliferation in oral squamous cell carcinoma? A prospective randomized clinical study

PURPOSE

There has been much interest in the role that the signaling molecule nitric oxide (NO) plays in cancer. NO has both tumor-promoting and tumor-inhibiting effects that are dependent on its local tissue concentration. In animal studies, the administration of exogenous NO has reduced both tumor growth and dissemination, and in vitro NO administration causes death of oral cancer cell lines. We evaluated the oral administration of the NO donor drug isosorbide mononitrate (ISMO) on cellular proliferation in patients with oral squamous cell carcinoma.

MATERIALS AND METHODS

A prospective randomized double-blind study was performed on 31 patients with biopsy-confirmed oral squamous cell carcinoma. Following incisional biopsy, patients were randomized to receive either ISMO (at a dose of 20 mg twice a day) or placebo tablets for 2 weeks before definitive resection. Cellular proliferation was compared between biopsy and resection specimens, using the immunohistochemical marker Ki-67.

RESULTS

No statistical difference was found between Ki-67 indices in initial biopsy and resection specimens after ISMO (P =.23) or placebo (P =.5) administration. There were no obvious clinical changes seen in the tumor during the clinical trial as a result of ISMO administration.

CONCLUSION

Although high concentrations of NO are cytotoxic, it is unlikely that administration of NO at an increased dose would be useful in the management of oral cancer because this would result in unacceptable systemic side effects. The possible manipulation of NO in oral cancer is discussed.

Expression of inducible nitric oxide synthase in cutaneous adnexal tumours of the head and neck

Adnexal tumours are a rare heterogeneous group of neoplasms, most commonly found in the head and neck region. Although most are benign, malignant adnexal tumours often behave aggressively, resulting in early metastasis. There is increasing interest in the role that nitric oxide (NO) plays in the behaviour of many cancers. It is thought that NO, produced by the enzyme inducible NO synthase (iNOS), facilitates tumour growth and dissemination. iNOS has been studied in the common skin cancers, where its expression correlates with tumour behaviour, but it has not been previously investigated in cutaneous adnexal tumours. An immunhistochemical study was performed using a monoclonal antibody to iNOS in 37 cases of adnexal tumours (19 benign, 18 malignant). iNOS expression was weakly expressed by basal keratinocytes of adjacent skin in all cases and it was variably expressed in the tumours. Malignant tumours had significantly increased iNOS expression when compared to both adjacent skin (P<0.001) and the benign tumour group (P<0.001). No significant difference was found between iNOS expression in benign tumour and adjacent skin (P=0.5). The role of iNOS in this rare group of tumours and the possibility of pharmacologically inhibiting it in the clinical setting warrants further investigation.

Expression of inducible nitric oxide synthase in bone metastases

AIMS

The signalling molecule nitric oxide (NO), produced predominantly in cancer by the enzyme inducible NO synthase (iNOS), has been implicated in the pathophysiology of many human tumours. The increased NO concentrations found in many human cancers may facilitate both angiogenesis and tumour dissemination. NO also plays a concentration-dependent role in bone re-modelling by acting on osteoclasts. Although iNOS has been studied extensively in most primary tumours, there are no reports that have investigated its expression in metastatic bone disease.

METHODS

An immunohistochemical study was performed using a monoclonal antibody to iNOS in 27 cases of breast, renal and lung bone metastases, biopsied at the time of treatment for pathological fracture.

RESULTS

iNOS expression was found in 14 cases and was predominantly localised to tumour cells in the metastatic deposits. A significant difference was found between iNOS expression in metastases and adjacent bone (p<0.001), where immunostaining was rarely seen and confined to immune cells. No microscopic differences in bone architecture could be seen between iNOS positive and negative metastases, and no correlations were found between iNOS expression and clinico-pathological variables.

CONCLUSIONS

iNOS expression is not a pathognomonic finding in bone metastasis. Its role in the behaviour of bone metastases requires further investigation.

Expression of type 2 nitric oxide synthase and vascular endothelial growth factor in oral dysplasia

PURPOSE

The small molecule nitric oxide (NO), produced by a family of enzymes called NO synthase (NOS), has a diverse array of functions in both physiologic and pathologic states. Prolonged production of NO by the isoform NOS2 has been implicated in human cancer progression. NO has an important role in angiogenesis, being both an upstream signal and a downstream effector molecule to vascular endothelial growth factor (VEGF). The latter group of proteins are crucial for vascular endothelial cell proliferation and permeability. The expression of VEGF increases with cancer progression. Because angiogenesis is a prerequisite for the development of invasive cancer, this immunohistochemical study investigated the expression of NOS2 and VEGF in oral epithelial dysplasia.

MATERIALS AND METHODS

An immunohistochemical study was performed using monoclonal antibodies to NOS2 and VEGF on archival formalin-fixed, paraffin-embedded tissue of 33 cases of oral dysplasia.

RESULTS

A significant correlation was found between NOS2 and VEGF expression in oral dysplasia (P <.001). Expression of both NOS2 and VEGF also correlated with the severity of dysplasia (P <.001, P <.002).

CONCLUSIONS

These findings may provide further understanding to the complex transformation of oral epithelial dysplasia to invasive carcinoma and the role of angiogenesis in this process.

Expression of vascular endothelial growth factor in basal cell carcinoma and cutaneous squamous cell carcinoma of the head and neck

BACKGROUND

Basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) can both arise from any cutaneous epithelial surface. BCC are slow growing and rarely metastasise, whereas SCC are usually more aggressive. It is likely that the angiogenic process plays a key role in determining rate of growth and propensity for dissemination. Angiogenesis is a complex process requiring many factors and a pivotal group of proteins involved in this process is vascular endothelial growth factor (VEGF).

METHODS

Immunohistochemical expression of VEGF was assessed in 44 cases of BCC and 41 cases of cutaneous SCC from the head and neck region.

RESULTS

VEGF was expressed by blood vessel endothelial cells in both adjacent skin and tumour, and in the basal keratinocyte layer of epidermis. In BCC, VEGF was expressed by tumour epithelial cells, predominantly at the invasive tumour front, in 24/44 cases and its expression was significantly greater than in adjacent skin (p = 0.038). More widespread VEGF expression was found in 32/41 cases of SCC, and it was significantly associated with the degree of tumour differentiation (p < 0.001).

CONCLUSIONS

The patterns of VEGF expression in BCC and SCC may help to explain the different behaviour that is usually seen with these tumours.

Expression of type 2 nitric oxide synthase and p53 in Warthin's tumour of the parotid

Although the pathogenesis of Warthin's tumour is not fully understood, it is generally thought that the tumour arises from heterotopic salivary ducts within pre-existing lymphoid tissue. Prolonged nitric oxide (NO) production by the enzyme type 2 nitric oxide synthase (NOS2) has been implicated in the pathogenesis of many solid tumours, but not in Warthin's tumour. Since NO and NOS2 are known to be associated with p53, the immunohistochemical expression of both NOS2 and p53 was investigated in 23 cases of Warthin's tumour. Widespread diffuse cytoplasmic immunostaining for NOS2 was found in tumour epithelial cells of all 23 cases studied, and it was additionally expressed in normal salivary duct epithelium. p53 staining was localised to the nuclei of tumour epithelium in 16 cases, with a similar pattern of distribution to tumour NOS2 expression. A significant correlation was found between NOS2 and p53 staining in the tumours (P < 0.001). In contrast to NOS2, p53 was not expressed by normal salivary ductal cells in any of the cases studied. NOS2 is widely expressed by the tumour epithelium of Warthin's, and its association with p53 expression is discussed. The role of NO in the pathogenesis of Warthin's tumour remains to be established.

Expression of nitric oxide synthase-2 in cutaneous squamous cell carcinoma of the head and neck

Nitric oxide (NO) has a pivotal role in angiogenesis. The expression of NO synthase (NOS2) is down-regulated in basal cell skin cancer but we know of no studies that have investigated its expression in the more aggressive squamous cell skin carcinoma. This immunohistochemical study assessed NOS2 expression in 37 cases of head and neck squamous cell skin carcinoma. NOS2 expression was located in cells of the basal cell layer of epidermis, but was significantly increased in tumour epithelium. No correlations were found between NOS2 expression and tumour size or degree of tumour differentiation. The raised NO concentrations in these tumours may provide one explanation for their more aggressive behaviour than that of the slower-growing basal cell carcinoma.

Expression of type 2 nitric oxide synthase and p21 in oral squamous cell carcinoma

Nitric oxide (NO) has a complex role in tumour biology. Most cancer research has focused on the enzyme nitric oxide synthase-2 (NOS2), an inducible isoform responsible for prolonged NO production. In normal cells exposed to high NO concentrations, the tumour-suppressor gene, p53, promotes apoptosis via the p21 pathway, in an attempt to safeguard against potential NO-mediated DNA damage. In cancer cells with mutant p53, this pathway is unlikely to occur directly, although, p53-independent p21 expression and subsequent apoptosis can occur at higher NO concentrations. In this study, the possible direct association between NOS2 and p21 was assessed in oral squamous cell carcinoma. Immunohistochemistry was performed for NOS2 and p21 on 56 cases, and NOS2 activity was determined with citrulline assays in selected cases. A significant relationship was demonstrated between the immunohistochemical expression of NOS2 and its activity (P<0.001), but not between NOS2 and p21 expression (P=0.76). It is unlikely that the NO concentrations found in oral cancer (up to 10.3 pmol NO min(-1) mg protein(-1)) are sufficient to cause direct (p53-independent) p21 accumulation and subsequent apoptosis. As with many other tumours, since NO production has a detrimental role, its pharmacological inhibition in oral cancer represents an exciting area for possible future therapeutic manipulation.

Correlation between type II nitric oxide synthase and p53 expression in oral squamous cell carcinoma

Prolonged nitric oxide (NO) production by the enzyme type II nitric oxide synthase (NOS2) has been implicated in angiogenesis and metastasis of human cancers. In animal models, wild-type p53 (but not mutant) protein results in down-regulation of NOS2 expression, which reduces both tumour growth and dissemination. In the current study, we aimed to find out whether a correlation was present in oral squamous cell carcinoma. Fifty-six cases of squamous cell carcinoma were assessed immunohistochemically using antibodies to NOS2 and p53 (clone DO-7). We also confirmed NOS2 protein expression in selected cases using immunoblotting. The results were correlated with clinicopathological findings. Statistical analysis showed a significant relationship between p53 and NOS2 expression (P= 0.001). No relationship was found between size of tumour or histological degree of differentiation, and NOS2 expression in the primary tumour.

Nitric oxide synthase expression is downregulated in basal cell carcinoma of the head and neck

The small molecule nitric oxide (NO) has many actions, most of which are poorly understood. Recently, NO and related compounds have been implicated in skin damage caused by ultraviolet light although their exact role is not clear. We undertook an immuno histochemical study to assess the expression of type II NO synthase (NOS2) and type III (NOS3) in basal cell carcinomas (BCCs) of the head and neck. In all 48 cases studied, NOS2 was found in the basal cell layer of the skin at the tumour margin but it w as significantly reduced in the tumour epithelial cells (P=0.001). NOS3 was localized to the endothelium of the blood vessels in both skin and tumour in all cases, and it was not seen in the tumour epithelial cells. The results suggest that expression of NOS is down-regulated in basal cell carcinomas.

Expression of nitric oxide synthase in pleomorphic adenomas of the parotid

The actions of nitric oxide (NO) in the pathology of solid tumours are complicated and many are poorly understood because NO has both inhibitory and tumour-promoting activities. In the current study we aimed to find out immunohistochemically whether the expression of both the inducible (iNOS) and endothelial (eNOS) forms of the enzyme nitric oxide synthase (NOS) were changed in pleomorphic adenomas of the parotid compared with normal salivary tissue. There was a significant difference in staining for iNOS between the tumour and normal salivary tissue, with tumour epithelial cells being stained in 29 cases of the 30 cases studied (P< 0.0001). The luminal cells of the salivary ducts also stained, but not the normal salivary tissue. Immunohistochemistry for the eNOS isoenzyme showed moderate staining of the tumour epithelium in only three specimens. There was also mild staining in the salivary duct cells of the normal glandular tissue and in endothelium of blood vessels in both tumour and normal glandular tissue in the same 29 cases.

A study to assess inducible nitric oxide synthase expression in oral lichen planus

Nitric oxide (NO) has been implicated in a variety of diseases but has not been previously studied in oral lichen planus (OLP). Since OLP has a complex immunogenesis with abundant macrophage infiltration, this study determined by immunohistochemistry whether or not the expression of the inducible form of nitric oxide synthase (iNOS) was increased in this condition relative to normal mucosa. Thirty cases of OLP and 10 normal buccal mucosa biopsies were studied utilising primary antibodies to iNOS and CD68, a myelomonocytic marker. iNOS activity was additionally assessed using a [(14-)C]-labelled arginine to citrulline assay. CD68 expression was significantly increased in the cellular infiltrate of all 30 cases of OLP compared with normal mucosa (P<0.009). Although iNOS staining was seen in a minority of cells in nine cases, this was not statistically significant when compared with the absent staining in normal oral mucosa (P=0.26). Furthermore, the minimal iNOS activity found in OLP was similar to that in normal mucosa. We conclude that expression of iNOS by macrophages is downregulated in OLP and discuss the possible reasons for this finding.

Are myoepithelial cells responsible for the widespread expression of inducible nitric oxide synthase in pleomorphic adenoma? An immunohistochemical study

Many of the actions of nitric oxide (NO) are still poorly understood. Recently, it has been shown that the inducible isoform of the enzyme nitric oxide synthase, iNOS, is expressed in both salivary ducts and pleomorphic adenoma. The current immunohistochemistry study determined whether or not this distribution correlated with smooth muscle actin (SMA) expression, thereby suggesting the expression by myoepithelial cells in both sites. Twenty cases of histologically confirmed pleomorphic adenoma, the sections of which contained adjacent normal salivary gland tissue, were stained for iNOS and smooth muscle actin (clone 1A4). The salivary ducts of all cases were stained intensely by both antibodies, with smooth muscle actin staining also being noted around acini in the normal gland parenchyma. Moderate or heavy staining for iNOS was found in all specimens of pleomorphic adenoma, with smooth muscle actin being distributed in a similar manner in 19 cases. Smooth muscle actin, but not iNOS, was also noted in blood vessels of both normal glands and tumours. The correlation between iNOS and SMA in pleomorphic adenoma was significant (P<0.001). The presence of iNOS in normal salivary ducts and pleomorphic adenoma is most likely due to expression by myoepithelial cells.