Gordon Museum, Guy's Hospital, London SEl 9RT, UK Correspondence tor Mr J. 0. Maynard Cystic changes in the parotid gland are found occasionally in long-standing parotid obstruction. The cysts are multiple and usually < 0.5 cm in diameter. Lymphangiomas occur occasionally in children and are obvious at operation. Solitary cysts in otherwise normal glands are rare but are more commonly seen in the parotid than the submandibular salivary gland. They account for 2-5percent of all parotid masses or spaceoccupying lesions'. Because cystic degeneration occasionally occurs in salivary neoplasms, all solitary cystic lesions in the parotid were widely excised after nerve dissection. The results of this policy are presented.
Clinical descriptionSince 1967 a personal series of 324 parotidectomies was carried out for parotid masses. A parotid mass was defined as a probable cyst if it was obviously fluctuant on clinical examination and the diagnosis confirmed if it was clearly a cyst at operation. Twenty-four solitary cysts were widely excised during this period, an incidence of 7.4 per cent. In ten cases the histology showed the cyst to be a neoplasm-a surprisingly high incidence of nearly 42 per cent ( Table 1). Included among the non-neoplastic cysts were two large solitary cysts measuring 8 and 10 cm arising below the parotid and extending deep to the gland. They were thought on histological examination to be branchial cysts of second branchial cleft origin'. Three smaller cysts between 2 and 4 cm diameter lying in the central part of the parotid deep to the facial nerve and lined with squamous stratified epithelium were perhaps of first branchial cleft origin',3.The four cysts, classified as dermoid cysts, had arisen in the lower pole of the parotid and one on the anterior border and ranged between 1 and 2 cm in diameter.The neoplastic cysts were indistinguishable from the other cysts both clinically and at operation. Those that were pleomorphic adenomas had undergone central cystic degeneration. One measured 8 x 6 cm, was deep to the facial nerve and extended deeply behind the oropharynx. It had been explored abroad and left intact. It had the appearance of a thin-walled branchial cyst containing milky fluid. It was uncertain on histological examination whether it was a monomorphic or pleomorphic adenoma. One of the adenolymphomas was in the central part of the parotid; it had been repeatedly aspirated elsewhere and cytology had failed to demonstrate the presence of a neoplasm. The squamous cell carcinoma was a 1-cm plaque on the wall of a 4-cm thinwalled cyst. The four pleomorphic adenomas and the two carcinomas were followed up for a maximum of 15 years without recurrence.There were few complications of the operations. One patient with an infected probable first cleft branchial cyst has permanent weakness of the lower lip. A branch of the lower division of the facial nerve was closely adherent to the cyst wall and partly divided and then sutured. The remaining patients had no late detectable weakness of the facial ner...
