Bilateral parotid neoplasms

L'hyperplasie oncocytaire nodulaire multifocale de la glande parotide

OBJECTIVES

Oncocytic lesions rarely affect the parotid gland, accounting for less than 1% of all salivary lesions. The WHO classification described three main types: diffuse oncocytosis, focal nodular oncocytosis hyperplasia, and oncocytoma. Multifocal nodular oncocytosis hyperplasia of the parotid gland represents an extremely rare, non-tumorous pathology of the parotid gland.

MATERIAL AND METHODS

We report a case of multifocal nodular oncocytosis hyperplasia of the parotid gland in a 70-year-old woman who was referred for a left preauricular mass that had gradually increased in size over the last 2 years. No lymph node of the neck was palpable.

RESULTS

MRI demonstrated multiple bilateral lesions of the parotid glands. Total parotidectomy, preserving the facial nerve, was performed.

CONCLUSION

We discuss the physiopathology and the treatment of multifocal nodular oncocytosis hyperplasia and provide a review of the literature.

Multiple synchronous and metachronous neoplasms of the parotid gland: The Chichester experience

Parotid neoplasms are usually solitary and multiple tumours occurring in an individual are uncommon. The incidence and implications of multiple synchronous and metachronous tumours remains relatively unknown. We reviewed the case notes of 606 patients who had parotidectomies for neoplastic lesions over a 30 year period and identified 30 patients (5%) with multiple primary tumours. There were 24 patients with synchronous tumours and 6 with metachronous tumours. Sixteen of the synchronous tumours (67%) were ipsilateral, whereas all six metachronous tumours were contralateral. Preoperative examination was effective at detecting bilateral tumours but poor at detecting multiple ipsilateral tumours. Multiple tumours were likely to be of the same histology (n=24, 80%) and Warthin's was by far the most common multiple tumour. Ipsilateral tumours of differing histological types and identical tumours other than Wartin's were uncommon. All but one patient had superficial parotidectomies and there were no recurrences.

Multiple primary tumours of the parotid gland

The authors reviewed the clinical and histopathological records of 69 cases of multiple primary tumours (MPT) of the parotid gland treated at Peking University School of Stomatology. It accounted for 3.4% of all parotid tumours (2055 patients). Fifty-nine patients were male and 10 were female. The median age was 58 (range 24-80) years. The average time interval between the diagnosis of bilateral parotid tumours was 5 years (range 5 months-15 years). Three clinical types were classified as bilateral parotid tumours (31 cases), unilateral multifocal parotid tumours (29 cases), and the combination of bilateral parotid tumours with unilateral multifocal parotid tumours (9 cases). Histologically, Warthin's tumour was the most common type (60 patients), followed by pleomorphic adenoma (8 cases). Three cases were malignant including adenoid cystic carcinoma, squamous cell carcinoma and mucoepidermoid carcinoma. The histopathologies of tumours were of the same type in 63 patients, and distinctly different in six patients. The tumours were found and diagnosed synchronously in 48 patients, and metachronously in 21 patients. Since some parotid tumours are MPTs, careful preoperative diagnosis is necessary. B-mode ultrasound is the technique of choice for the screening of MPT. Meticulous intraoperative inspection and palpation of the glandular tissues and periglandular lymph nodes are necessary.