Int. J. Oral Maxillofac. Surg. 1994; 23:165-166 Printed in Denmark. All rights reserved

Copyright©Munksgaard 1994

lnternationalJouraal of

Oral & MaxillofaciaI Surgery

ISSN 0901-5027

Par0tid cyst: a case report K. Altman, B. M. W. Bailey Norman Rowe Maxillofacial Unit, Queen Mary's University Hospital, Roehampton, London SW15 5PN, UK

K. A l tman , B. M . W. Bailey." P a r o t i d cyst: a case report. Int. J. Oral Max i l lo fac . Surg. 1994; 23- 165-166. © Munksgaard, 1994

Abstrac t . A case of parotid cyst is reported, and the diagnosis, investigations, and treatment are discussed.

Key words: parotid gland; cysts.

Accepted for publication 15 November 1993

Cystic lesions of the parotid gland are uncommon, comprising approximately 5% of all salivary gland tumours; many of them represent cystic components of neoplasms 2.

Histologically, the main types of cyst that may be found in the parotid gland are as follows: 1) simple cysts, compar- able with both the extravasation and retention types of mucocele, but larger; 2) lymphoepithelial cysts, which are mainly congenital, but which are also reported in acquired immunodeficiency syndrome (AIDS) patientsS; 3) poly- cystic (dysgenetic) disease of the parotid

gland, a developmental disorder which is limited to the parotid glands, often in females, and usually bilateral9; and 4) cystic tumours.

This paper reports the case of a large intraparotid cyst and discusses the diag- nosis, relevant investigations, and treat- ment of this lesion.

Case report

A 10-year-old boy presented with a cystic swelling in front of the right ear. The lesion had been noticed a short time before; it was painless and thought to be enlarging. C!inical

examination revealed a 3-cm, soft, well-de- fined mass in the right preauricular region. A computerized tomography (CT) scan showed a 2.5 x 1.5 cm cyst extending from the anterior surface of the right parotid gland (Fig. 1).

At operation, via an extended preauricular incision, the cyst was excised with a margin of superficial lobe of parotid gland, the upper divisions of the facial nerve being dissected free. Histological examination revealed a sim- ple parotid cyst (Fig. 2). The lining consisted of a double layer of epithelium, stratified in some areas, and there was a fibrocollagenous wall. Myxoid change and foci of parotid gland acini were seen, and the cyst contents

Fig. 1. Axial CT scan showing large cyst in right parotid gland.

Fig. 2. Photomicrograph showing collapsed, thin-walled cyst and adjacent parotid gland acini (HE x 25). Inset: high-power photomicrograph showing double layer of squamous epithelium and fibrocollagenous wall (HE × 400).

166 Altman and Bailey

were of gelatinous material. The patient made an uneventful recovery, and there has been no sign of recurrence.

Discussion

Intraparotid cystic swellings are uncom- mon. RICHARDSON et al. 7 found 23 cystic lesions (3.2%) in a series of 708 parotid- ectomies; of these, 16 (2.3%) met their criteria for lymphoepithelial cysts, while five (0.7%) were simple cysts. PIETERSE

SEYMOUR 6 reported 16 intraparotid cysts (8.7%) in 183 cases. Nine (4.9%) had developed in parotid neoplasms, usually Warthin's tumours, while the re- maining seven (3.8%) had no associated tumours. ADEKEYE ~ ORD 1, in a review of 100 cases, found parotid cyst to be the commonest nonneoplast ic disease (10%). Histologically, seven of these were simple cysts and two were lympho- epithelial cysts.

The clinical diagnosis of parot id cyst is often based on a slowly enlarging painless lump in the parotid region, and examination may not always confirm the cystic nature of the lesion. Investiga- tions are important in diagnosis and treatment planning of these lesions. Fine-needle aspiration cytology (FNAC) is useful in certain cases 4. Sialography is not helpful in establish- ing the diagnosis, but does confirm the presence of a space-occupying lesion 3. Ul t rasound is useful in showing the cys- tic nature of the lesion ~°, while CT scan- ning, with the possible use of contrast,

gives clear images o f the lesion and its anatomical relations, as in the patient reported here; moreover, it can detect bilateral disease and any associated cer- vical lymphadenopathy, as in patients at risk of developing AIDS 5,8. Magnet ic resonance imaging (MRI) can reveal intraparotid cystic disease 8 and is gener- ally more sensitive than CT scanning in detecting small intraparot id masses, al though the latter provides a better means of distinguishing solid from cys- tic lesions.

Treatment in the case reported was by surgical excision o f the cyst with a margin of superficial lobe of parot id gland, after dissecting the branches of the facial nerve. BRENNAN et al. 3 advo- cate this type of conservative surgery whenever possible. Survey of the litera- ture reveals that most other authors fav- our superficial parot idectomy in these cases, especially if the diagnosis is in doubt or when a conservative approach cannot safely remove the lesion.

References

1. ADEKEYE EO, ORD RA. Surgical parotid disease in Nigeria: a review of 100 cases. J Maxillofac Surg 1984: 12:118-22.

2. BATSAKIS JG. Tumors of the head and neck. Baltimore, MD: Williams & Wilk- ins, 1974: 63.

3. BRENNAN MF, GWYNNE JF, MACBETH WAAG. Simple parotid cysts. Aust N Z J Surg 1970: 40: 15-19.

4. DROESE M. Cytological diagnosis of siala-

denosis, sialadenitis, and parotid cysts by fine-needle aspiration biopsy. Adv Oto- rhinolaryngol 1981: 26:49 96.

5. HOLLIDAY RA, COHEN WA, SCH1NELLA RA, et al. Benign lymphoepithelial pa- rotid cysts and hyperplastic cervical adenopathy in AIDS-risk patients: a new CT appearance. Radiology 1988: 168: 439--41.

6. PIETERSE AS, SEYMOUR AE. Parotid cysts. an analysis of 16 cases and suggested classification. Pathology 1981: 13: 225- 34.

7. RICHARDSON GS, CLAIRMONT AA, ERICKSON ER. Cystic lesions of the pa- rotid gland. Plast Reconstr Surg 1978: 61: 364-70.

8. SHUGAR JM, SOM PM, JACOBSON AL, RYAN JR, BERNARD PJ, DICKMAN SH. Multicentric parotid cysts and cervical adenopathy in AIDS patients. A newly recognised entity: CT and MR manifes- tations. Laryngoscope 1988: 98: 77~5.

9. SMYTH AG, WARD-BooTh RP, HmH AS. Polycystic disease of the parotid glands: two familial cases. Br J Oral Maxillofac Surg 1993: 31: 38-40.

10. WARD-BOOTH RP, WILLIAMS ED, FAULK- NER TP, EARL PD. Ultrasound: a simple noninvasive examination of cervical swellings. Plast Reconstr Surg 1984: 73: 577-81.

Address: K. Altman, Registrar Norman Rowe Maxillofacial Unit Queen Mary's University Hospital Roehampton Lane London SWI5 5PN UK