A false aneurysm of the internal maxillary artery presented with clinical and radiological features suggestive of a malignant tumour of the maxillary sinus. This case illustrates a complication of antral lavage and an unusual clinical, radiological and pathological entity.

Haemangiopericytomas involving the parotid gland are uncommon and those arising from the gland itself are rare. Three examples of primary parotid gland hemangiopericytoma are presented. The biological course of parotid or periparotid haemangiopericytomas does not differ from that manifested by their counterparts arising from somatic soft tumours.

A 51-year-old female presented with a sensation of a lump in the throat for five months. Clinical examination was normal.The barium swallow and the CT scan showed a well-defined mass to the left of the upper oesophagus and behind it. The mass was removed surgically and shown pathologically to be a nodule of ectopic thyroid tissue. This very rare pathology is discussed together with a review of the relevant literature.

Aneurysmal bone cyst is a rare lesion usually of the long bones, well documented in the literature. It is a cystic, osteolytic vascular tumour, replete with giant cells and fibrous septa, yet devoid of endothelial lining. It has been reported in the larynx and maxillary sinus. This appears to be the first report Qf an aneurysmal bone cyst occurring in the hyoid bone.

Rhinosporidiosis is the disease resulting from infection by Rhinosporidiosum seeberi, an organism endemic in the Indian sub-continent, but rarely seen in the United Kingdom.

We describe the clinio-pathological features of a case presenting in a 14-year-old female.

A case of cutaneous T-cell lymphoma is presented in which the diagnosis was obscured by a concomitant granulomatous infiltrate. A working diagnosis of tuberculosis delayed appropriate treatment for several months over which time rapid progression of the disease was seen. Inclusion of overlying skin in the repeat biopsies yielded the histological information to establish the correct diagnosis and there was rapid regression on completion of a course of radiotherapy.

Synovial sarcoma of the hypopharynx is a rare neoplasm. To date only 23 cases of synovial sarcoma of the hypopharynx have been reported in the literature. An additional case in an 18-year-old male is presented. This is the first case of synovial sarcoma in the hypopharynx to be reported in Singapore. The presentation was that of a mass in the hypopharynx; progressive dysphagia, intermittent hoarseness and gradual airway compromise. A CT scan was valuable in determining the site of origin and extent of the lesion. Histopathology was diagnostic. Treatment comprised of wide surgical excision of the tumour and post-operative radiotherapy.

Malakoplakia presenting in the head and neck is very rare. We present a case of an inflammatory mass in the neck, clinically mimicking actinomycosis in a 67-year-old man. Repeated culture of E. coli and histological and electron microscopic examination of biopsy material showed an infiltration of granular macrophages and intracellular gram negative bacilli, but no classical Michaelis-Gutmann bodies. The clinical and pathological findings and criteria for the diagnosis of malakoplakia are discussed.

It is now a widely held belief that so-called ‘lateral aberrant thyroid’ tissue actually represents a metastasis from a malignant tumour of the thyroid gland. A case is presented which suggests that this is not always true, and an extensive review of the relevant literature is discussed.

Pneumoparotitis is a rare cause of parotid enlargement. It is due to a reflux of air through Stensen's duct into the acini of the parotid gland with subsequent dilatation. We report a case which followed a long history of autoinflation of the middle ears by the Valsalva manoeuvre. The plain radiographic, sialographic and ultrasound findings are presented.

Invasion of the adventitia of the carotid artery by tumour is not demonstrated by contrast CT scanning. We report a case in which B-mode ultrasound was successfully used to demonstrate this.