Congenital absence of the parotid gland is extremely infrequent. We presenthere a case of unilateral parotid gland agenesis with pleomorphic adenoma of the contralateral parotid gland. Even though pleomorphic adenoma is the most common tumour of the parotid gland, to our knowledge this is the first case of these two conditions being seen together.

This study examines the expression HO-1 and HO-2 isozymes in human parotid pleomorphic adenomas. They are members of the heat shock protein family, and are thought to play a role in the regulation of tumoral blood flow. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were undertaken in 12 pleomorphic adenoma specimens, all sections of which contained adjacent normal salivary tissue. Normal salivary gland acini and ducts displayed significantly stronger immunoreactivity for HO-2 compared to tumour cells (p < 0.001). Expression for HO-1 was minimal in both normal salivary gland acini and tumour cells with no difference (p = 1.000). However, positive staining for HO-1 was seen in normal salivary ducts and in pleomorphic adenomas showing ductal differentiation. In conclusion, this is the first study to examine the expression of HO-1 and HO-2 within normal salivary glands and pleomorphic adenomas. Our findings suggest that HO may be implicated in the pathogenesis of salivary pleomorphic adenomas.

A case of an 87-year-old female with pleomorphic adenoma of the tongue base is reported, with a review of the literature. The tumour had enlarged gradually over a period of three years, causing dysphagia and dysphasia. Computed tomography and magnetic resonance imaging showed that the tumour was exophytic and occupy the oropharynx with little extension into the muscle tissue. The tumour was resected by CO2 laser. Histological examination revealed a benign pleomorphic adenoma that originated from the minor salivary gland of the tongue base.

A rare case of an intratemporal pleomorphic adenoma is presented and the management of such a tumour is discussed. Some anatomical aspects of the facial nerve, pertinent to the pathophysiology of facial paralysis are outlined. This case demonstrates that tumour extension into the temporal bone can be resected successfully at initial surgery with excellent facial nerve functional outcome. We advocate exploration of the fallopian canal to be carried out at primary surgery and be performed by a surgeon familiar with the surgical anatomy of the intratemporal segment of the facial nerve. This approach will reduce the risk of facial nerve injury and palsy both at surgery and subsequently.

A case is reported of a pleomorphic adenoma of the minor salivary glands of the oral cavity presenting with acute airway obstruction. This is the first reported case to our knowledge of a mixed salivary tumour of the upper respiratory tract causing upper airway obstruction and acute respiratory failure. The patient had to be intubated and transferred to the intensive care unit. After an elective tracheostomy was performed, the adenoma was excised from its fibrous capsule. It was found to originate from the soft palate and occupied the parapharyngeal space. A high index of suspicion should be kept in order to diagnose tumours of the parapharyngeal space with unusual presentation. These tumours which are usually benign should be considered in the differential diagnosis from more common infectious or traumatic conditions and surgical morbidity should be minimal.

Cervical heterotopic salivary tissues are rare and are predominantly found in the anterior triangle of the neck especially at the anterior border of the sternocleidomastoid muscl. We report a case of pleomorphic adenoma arising in the left posterior triangle of the neck.

Benign salivary gland tumours in childhood are rare. We present a case of a pleomorphic adenoma arising in a minor salivary gland within the hard palate, review the literature and discuss the diagnostic and therapeutic features of the condition.