Salivary gland myoepitheliomas are rare tumours, accounting for less than 1 per cent of neoplasms of the salivary glands. Myoepithelioma of the palate is very rare, and only a few cases have been reported in the world literature. Histological and immunohistochemical analysis supports the myoepithelial origin of this tumour. Here, we report three cases of myoepithelioma of the palate in adult males and review previously reported cases.

Cystadenocarcinoma (papillary cystadenocarcinoma) of the salivary gland is a rare malignant neoplasm. Major locations of this neoplasm are the parotid gland, the sublingual gland, and minor salivary glands, while occurrence in the submandibular gland is extremely rare. As far as we know, only one report, written in the French language, has been published concerning cystadenocarcinoma of the submandibular gland, but no report is available in the English language. In this report, we describe a case of cystadenocarcinoma arising from the submandibular gland of a 54-year-old male patient. The neoplasm is a low-grade carcinoma, and pre-operative examination may not show typical characteristics of malignant neoplasms. Therefore, as was true in this case, the differential diagnosis from benign lesions is sometimes difficult. This is the first report on cystadenocarcinoma of the submandibular gland in the English language and the first to show a computed tomography (CT) scan and magnetic resonance imaging (MRI) of this neoplasm in the submandibular gland.

Hyalinizing clear cell carcinoma (HCCC) of the salivary gland is new disease only recognized in recent years. It is rare and the standard treatment is still under investigation. This is a report of a 42-year-old female with HCCC who presented with a painless submucosal hard palatal mass of three years duration. Wide excision of the tumour and the underlying palatal and maxillary bones was performed. Pathological examination revealed typical clear cells arranged in anastomosing trabeculae, cords, nests, or solid sheets with a hyalinizing stroma. These clear cells were positive for the periodic acid-Schiff (PAS) reaction but were negative for the mucin stain. Immunohistochemically, these neoplastic cells were positive for cytokeratin, but negative for actin. No recurrence nor distant metastasis was found during the eight-month follow-up period.

The present paper describes the first reported case, to our knowledge, of a myoepithelioma arising in an accessory parotid gland. Because pre-operative fine-needle aspiration cytological findings and operative findings suggested that this tumour was malignant, the decision was made to remove the tumour surgically along with the buccal branches of the facial nerve. The resected nerve was reconstructed by nerve transplantation, using the great auricular nerve. Subsequently the tumour was found to be benign. One year after surgery, the patient had excellent facial nerve function and so far there has been no evidence of recurrence.

The majority of salivary gland tumours present as a single mass in one gland. Sometimes multiple primary neoplasms can be seen in more than one salivary gland. The most common tumour is Warthin’s tumour. Multiple primary pleomorphic adenomas are extremely rare. Most of them are in the major salivary glands. The author reports the first case of simultaneous pleomorphic adenomas in the parotid gland and minor salivary gland at the parapharyngeal space.

Calcium pyrophosphate dihydrate crystal deposition disease, exhibits several clinical manifestations, from absence of symptoms to severely destructive arthropathy or conditions simulating neoplasm, which is frequently related to the temporomandibular joint. Fifteen of the 31 reported cases of tophaceous pseudogout were found in the head and neck region. A patient presented with a parotid swelling, which initially was suspected to be malignant because of the following findings: radiodensity, progression into the joint, osseous destruction of the major ala of the sphenoid and a fine needle aspirate with crystals, osteoblasts, megakaryocytes and irregular cells of varying size. At surgery there was found a tumour consisting of a white, firm gritty material. It progressed to the skull base where material had to be left, because of the presence of the nerves and vessels. A frozen specimen was reported to be benign. Histological examination showed inflammatory cells, macrophages, a chondroid material with embedded metaplastic chondroid cells and giant cells of foreign body type. Crystal examination of X-ray diffraction revealed calcium pyrophosphate dihydrate.

Epithelial-myoepithelial carcinoma (EMC) is a rare biphasic tumour of the salivary glands typically arising in the parotid. Fine needle aspiration cytology is widely used in the initial investigation of salivary gland swellings and whilst the cytological features of this tumour have been described they are not well recognized. This report describes the clinicopathological features of a case of epithelial-myoepithelial carcinoma of the parotid gland and highlights the importance of awareness of this tumour in the differential diagnosis of biphasic tumours on fine needle aspiration cytology.

Salivary tissue intraductal papillomas are rare, benign tumours that predominantly affect minor salivary glands. We report a case of an intraductal papilloma arising in the unusual site of the submandibular gland. The tumour was completely excised and recurrence is not expected. A brief review of this histologically distinct lesion is presented.

Pleomorphic adenoma is the commonest benign tumour of the major salivary glands. It can also occur in minor salivary glands, mainly in the oral cavity, but also in other sites in the head and neck both within and outwith the upper aerodigestive tract. We present a rare case of pleomorphic adenoma of the nasal septum with consideration of the clinical management and a review of the literature.

Salivary tissue neoplasms may involve normal, accessory and heterotopic salivary gland tissue. A case of Warthin's tumour originating from heterotopic salivary gland tissue of the upper neck is reported. The radioactive uptake of 131I, evidenced in the neck mass in its pre-diagnostic assessment, suggested a diagnosis of cervical node involvement from a primary malignant thyroid neoplasm. A critical review of the literature on heterotopic salivary gland tissue neoplasms of the head and neck is also presented.

Lipomata are rare tumours of the parotid gland. The plemorphic lipoma represents an unusual histological variant of the benign lipoma. We report a case of a pleomorphic lipoma arising in the parotid gland. Only one case of a similar nature has previously been recorded. This tumour is benign, was fully excised and recurrence is not expected.

A rare case of pleomorphic adenoma of the base of the tongue with a relevant review of literature is reported.

Canalicular adenoma is a recently classified uncommon salivary gland neoplasm. This biologically benign growth tends to be multifocal and occurs most often in the upper lips of elderly people. Histologically and clinically it differs from the basal cell adenoma, for which it may be mistaken, in a number of ways. Its clinical importance lies in the fact that it may be confused with malignancy. Little information is available regarding the recurrence and long-term follow-up of these tumours, and where available it covers only relatively short periods.

We report the recurrence of a canalicular adenoma after an 11.2 year disease-free period.

In order to assess its discriminating and prognostic value, we studied the immunoreactivity for proliferating cell nuclear antigen (PCNA) in tissue from 52 human salivary gland tumours using the murine monoclonal antibody PC10.

The PCNA percentage count, namely, the average number of positive nuclei counted per 100 randomly selected tumour cells was recorded for each tumour. Anaplastic carcinoma was used as a positive control and histologically ‘normal’ salivary gland and tonsil served as a negative control.

A PCNA count of 30 per cent was postulated to predict malignancy within a given salivary gland tumour i.e. a PCNA count of 30 per cent or above would indicate malignant potential. This gave a sensitivity of 96.9 per cent and a specificity of 95.2 per cent and a positive predictive value of determining malignancy of 96.8 per cent.

We conclude that PCNA immunoreactivity is useful in discriminating between benign and malignant salivary gland tumours and that it may have prognostic value in this diverse group of neoplasms.

Epithelial-myoepithelial carcinoma (EMC) accounts for approximately one per cent of salivary gland tumours. This tumour is gaining wider recognition following inclusion into the WHO histological classification of salivary gland tumours in 1990. Salivary gland tumours characteristically present with an enlarging mass. We describe an unusual presentation of a salivary gland tumour with stenosis of the external ear canal in the absence of a palpable mass. EMC usually arises from the salivary glands but isolated cases have been described arising primarily from the paranasal sinuses, trachea and lacrimal gland. The management of this tumour is still evolving with surgical excision being the main-stay of treatment. The efficacy of radiotherapy has not yet been established but high local recurrence rates despite apparently adequate excision and the possibility of a multicentric origin of the tumour may herald an increasing role for radiotherapy in the future. We stress the importance of awareness of adjacent structures when considering the cause of cartilaginous canal stenosis.

Adenoid cystic carcinoma is the commonest tumour of minor salivary glands. In the case described here a pulmonary mass was found. This was likely to be a distant metastasis, particularly as the primary tumour was of cribriform subtype with perineural invasion and resection was microscopically incomplete. However, surgical excision of the pulmonary mass enabled histopathological studies to be carried out which found it to be an unrelated bronchioloalveolar carcinoma.

We report the previously undocumented development of an orbital metastasis and skin metastases in a patient with polymorphous low grade adenocarcinoma (PLGA) 15 years after initial presentation. The clinical course, treatment and changing histological features are discussed.

Sialadenoma papilliferum is a rare, benign, exophytic tumour of the salivary glands. The prognosis is exceptionally good. Since the lesion was first described, 30 cases have been reported in the English literature. and only one of these is known to have recurred.

A case of sialadenoma papilliferum occurring in the buccal mucosa with recurrence three years after local excision, is presented. The literature is briefly discussed.