Surgical treatment of parotid tumors in the general community hospital.

ABSTRACT: We reviewed 51 consecutive parotidectomies done at a general community hospital and gathered data on age and sex of the patients, length of stay in the hospital, perioperative outcome, complications, and surgical pathology. Statistical method included logistic regression and ANOVA to determine relationship and dependence of the variables. There were 24 male and 27 female patients. Thirty-six (70.6%) of the parotid tumors were benign. There were no major complications. Treatment of parotid tumors in the community hospital is feasible and safe if basic guidelines are implemented. The epidemiology of parotid tumors in the relatively smaller hospital should resemble that reported in the literature. Our data suggest that parotid malignancy may occur more frequently in elderly men and that length of stay in the hospital may be longer for patients having surgery for malignant than for benign parotid tumors.

**********

MOST SERIES on parotid tumors are based on the experience of large institutions, with data collected over a long period. The absence of articles on the subject from smaller community hospitals may be related to the inability of these centers to generate large numbers of cases of parotid tumors. Indeed, local physicians and surgeons may be too willing to refer patients with these tumors to tertiary hospitals either because of their relative infrequency, concern about the lack of expertise required to treat them, or to avoid the potential for catastrophic facial nerve paralysis or complication. Because information is needed on epidemiology, complication rate, and outcome of treatment of parotid tumors in smaller hospitals, we reviewed 51 consecutive parotidectomies done by our community based otolaryngology practice. Our series attempts to compare its data with that of larger published reports and analyzes perioperative and short-term results.

METHODS

A total of 51 consecutive parotidectomies were analyzed to determine statistical relationships among the patient's sex, age, postoperative length of stay in the hospital, and final pathology results. In all cases, surgery was done to treat a parotid mass or tumor. These procedures were done at a 160-bed general community hospital in Broward County, Florida from 1991 to 1999 by board certified otolaryngologists/head and neck surgeons. Most of the patients had a lateral lobe parotidectomy with dissection and preservation of the facial nerve. Patients with malignancy required a more extensive operation. The surgical equipment used in most procedures included a standard thyroid surgery tray, bipolar electrocautery, a contact Nd:YAG laser used to dissect the parotid gland, and a nerve stimulator used to identify and preserve the facial nerve. Home discharge criteria required that the patient be stable in general terms and exhibit adequate wound healing, with a wound drainage rate less than 20 mL within the previou s 24 hours. These patients had follow-up in the office 1 week postoperatively and as necessary afterward.

The statistical analysis used to study the sample included logistic regression to determine the relationship between age and sex, and pathology, age, and sex. ANOVA was used to determine the dependence of the length of stay on pathology, age, and sex.

RESULTS

Of the 51 patients who had parotidectomy, 24 were male, with a mean age of 66.9 years, and 27 were female, with a mean age of 60.1 years. Benign disease was found in 36 cases (71%) and malignant disease in 15 (29%). The most common benign tumors were pleomorphic adenoma or mixed tumor, comprising 50% of all benign tumors (88% occurring in women), and Warthin's tumor or adenolymphoma, mostly seen in men. The most frequently reported malignancies were squamous cell carcinoma, comprising 40% of all cancers, seen predominantly in men, and adenocarcinoma, comprising 33% of all malignancies reported (Table 1).

Statistical analysis suggested that sex was a significant predictor of malignancy versus nonmalignancy (P = .019), indicating that malignancy was more frequent in men (Table 2). Stratifying the data by age group revealed a significant interaction between age and sex; in the group more than 65 years of age, again sex was a significant predictor of malignancy vs nonmalignancy (P = .036), men being significantly more likely to have malignant disease than women (Table 3). Length of hospital stay was 2 days for 62% of the patients who had benign disease, whereas 50 of those with malignant disease had a length of stay of 3 days and another 25%, 2 days (Table 4).

DISCUSSION

Our results are in general agreement with published epidemiologic data on parotid tumors. (1-7) The majority of the tumors were benign, the most frequent being pleomorphic adenoma and Warthin's tumor. Pleomorphic adenoma and inflammatory tumors were more frequent in women. The majority of Warthin's tumors and malignancies were seen in men. Mucoepidermoid carcinoma, one of the most frequent malignancies reported in large series, is missing in our sample, perhaps because its incidence peaks in younger individuals.

Parotid neoplasms are uncommon, comprising approximately 3% of all head and neck tumors and presenting an incidence of less than 3 per 100,000 population. (8) Most articles on parotid tumors have originated at large institutions and over a long period. Because these tumor are infrequent, few publications on the subject have come from relatively small general community hospitals such as ours. Our experience may be skewed because ours is a teaching multispecialty group practice known for advanced tertiary medicine. The demographics of Broward County also may have influenced our statistics, since the hospital services a large elderly retired population living in the county and it is known that parotid tumors peak in frequency in the sixth and seventh decades. (9,10)

Review of the medical records did not reveal any significant or major intraoperative or postoperative complications. Measured anesthesia and surgery times were considered reasonable and unremarkable. In all procedures, the main trunk of the facial nerve and all associated or adjacent branches were identified before excision of the tumor and were preserved. No major complications were reported either for benign or malignant disease, even though procedures done for malignancy were more extensive. The patients who had parotidectomy for malignant disease were subjected to wider excisions, more extensive dissections of the facial nerve, and/or total parotidectomy or neck dissection as indicated. (11,12) None of the patients had permanent facial paralysis or paresis as a result of the operation. The most significant and frequent postoperative complication was temporary marginal mandibular nerve branch paresis, resulting in lower lip weakness but resolving within a period of 16 weeks. This transient nerve injury was most likely caused by iatrogenic neurapraxia due to either stretching or pulling of the nerve during dissection or close cauterization of adjacent tissue with the bipolar electrocoagulator. The marginal mandibular branch is at greater risk for weakness than the rest of the nerve because of its close proximity to the tail and inferoposterior part of the parotid, an area most commonly affected by tumors. Additionally this branch is the longest and may require more manipulation during dissection. Another complication reported by the vast majority of our patients consisted of transient paresthesia of the ipsilateral auricle. This symptom is usually caused by mobilization or by discontinuity of the greater auricular nerve, which courses in close proximity to the parotid tail and supplies sensory function to the periauricular region.

In all of these parotidectomies, the nerve stimulator was considered an essential tool to identify, dissect, and preserve the facial nerve. Under no circumstances would surgeons have operated without this piece of equipment for fear of injuring the facial nerve. On the other hand, the facial nerve monitor was not available for use in this group of operations and although useful, was not considered then as standard of care. (13, 14) The use of bipolar cautery aided in the control of electrocoagulation by limiting the spread of energy into adjacent tissue, minimizing collateral injury. The contact Nd:YAG laser used in most of these operations provided some advantage with hemostasis and accuracy of dissection and was considered a preferred tool but not essential.

CONCLUSION

Successful surgical treatment of parotid tumors is feasible in the general community hospital and can greatly enhance the medical services that these institutions provide. Greater statistical power could be gained in this series by adding more observations. It is important to note that this work reports on short-term clinical perioperative outcome but does not address any long-term issues.

Epidemiologic data suggest that the majority of parotid tumors likely to be encountered in the clinical setting will be benign. Indeed, the incidence of parotid tumors in a community hospital should resemble that reported in the literature. The frequency of all parotid tumors and specifically malignancies may increase if the hospital services an older population.

The most common procedure done to treat benign tumors consisted of lateral lobe parotidectomy with dissection and preservation of the facial nerve. Malignancies may have required more extensive operations including neck dissection. The complications that were recorded in this series were considered either expected or minor and were all transient.

To successfully treat parotid tumors in such a setting requires, at the very least, the presence of board certified surgeons with special expertise in the head and neck area, a competent pathology department, and nerve stimulation equipment. Statistical analysis of this series suggests that parotid malignancy may occur more frequently in elderly men and that the hospitalization may be longer for patients having surgery for malignancy than for benign parotid disease.

TABLE 1

Distribution and Frequency of Parotid Tumors by Pathology and Patient
Sex

      Type of Tumor                Male                 Female

Benign
  Pleomorphic adenoma         2                  16
  Warthin's tumor             6                   2
  Inflammatory                1                   5
  Monomorphic adenoma         3
  Lipoma                      1
    Subtotal                         13                    23

Malignant tumors
  Squamous cell carcinoma     5                   1
  Adenocarcinoma              3                   2
  Lymphoma                    1                   1
  Merkle cell carcinoma       1
  Basaloid neoplasm           1
    Subtotal                         11                     4

      Total                          24                    27

      Type of Tumor               Total

Benign
  Pleomorphic adenoma           18
  Warthin's tumor                8
  Inflammatory                   6
  Monomorphic adenoma            3
  Lipoma                         1
    Subtotal                         36

Malignant tumors
  Squamous cell carcinoma        6
  Adenocarcinoma                 5
  Lymphoma                       2
  Merkle cell carcinoma          1
  Basaloid neoplasm              1
    Subtotal                         15

      Total                          51

TABLE 2

Pathology as Function of Sex

Sex         Nonmalignant  Malignant    Total

Female           23           4          27
Male             13          11          24

 Total           36          15          51

                 DF         Value    Probability

Chi-square       1          5.888       .015

TABLE 3

Pathology as Function of Sex and Age > 65 Years

Sex         Nonmalignant  Malignant     Total

Female           13           2          15
Male              9           9          18

Total            22          11          33

                 DF         Value    Probability

Chi-square       1          4.950       .026

TABLE 4

Length of Hospital Stay as Function of Pathology

                                 Length of Stay (Days)

Pathology     1         2         3         4         5         6

Benign        2         8         1         1         1         0
Inflammatory  4         0         0         0         0         0
Malignant     0         2         4         0         1         1

Total         6         10        5         1         2         1



Pathology     Total

Benign           13
Inflammatory      4
Malignant         8

Total            25

Acknowledgments. We thank Gerald Zuckier, PhD, from Bayer Pharmaceutical Division for epidemiology and data analysis.

References

(1.) Spiro RH: Salivary neoplasms: overview of a 35 year experience with 2807 patients. Head Neck 1986; 8:177-184

(2.) Ostman J, Anneroth G, Gustafsson A, et al: Malignant salivary gland tumours in Sweden 1960-1989. an epidemiological study. Oral Oncol 1997; 33:169-176

(3.) Pinkston JA, Cole P: Incidence rates of salivary gland tumors: results from a population-based study. Otolaryngol Head Neck Surg 1999; 120:834-840

(4.) Gunn A, Parrot NR: Parotid tumours: a review of parotid tumour surgery in the Northern Regional Health Authority of the United Kingdom. 1978.1982. Br J Surg 1988; 75:11441146

(5.) Skolnick EM, Friedman M, Becker 5, et al: Tumors of the major salivary glands. Laryngascope 1977; 87:843-861

(6.) Renehan A, Gleave EN, Hancock BD, et al: Long-term follow-up of over 1000 patients with salivary gland tumours treated in a single centre. Br J Surg 1996; 83:1750-1754

(7.) Main JH, Orr JA, McGurk FM, et al: Salivary gland tumours: review of 643 cases. J Oral Pathol 1976; 5:88-102

(8.) Leegaard T, Lindeman H: Salivary gland tumors: clinical picture and treatment. Acta Otolaryngol 1970; 263:155-159

(9.) Rollins L Jr, Rollins L: Tumors of the salivary glands. Am Surg 1979; 45:561-564

(10.) Eveson JM, Cawson RA: Salivary gland tumors. a review of 2410 cases with particular reference to histological types, site, age, and sex distribution. J Pathol 1985; 146:51-58

(11.) Johson JT: Parotid. Operative Otolaryngol Head Neck Surg. Myers EN (ed). Philadelphia, WB Saunders Go, Vol 1, 1997, pp 504-518

(12.) Rea JL: Partial parotidectomies: morbidity and benign tumor recurrence rates in a series of 94 cases. Laryngoscope 2000; 110:924-927

(13.) Witt RL: Facial nerve function after partial superficial parotidectomy: an 11-year review (1987-1997). Otolaryngol Head Neck Surg 1999; 121:210-213

(14.) Witt RL: Facial nerve monitoring in parotid surgery: the standard of care? Otolaryngol Head Neck Surg 1998; 119:468-470

KEY POINTS

* The epidemiology of parotid tumors presenting at a general community hospital should parallel that described by large series from tertiary referral medical centers.

* Guidelines to ensure safety and feasibility of treatment of parotid tumors should include participation of qualified surgeons and pathologists, as well as use of the facial nerve monitor.

* Postoperative length of stay after parotidectomy is longer in elderly men presenting with malignancy.

From the Department of Otolaryngology, University of Miami School of Medicine, Miami, Fla. (Mr. Ackerman is a first-year medical student at the University of Miami. Dr. Hanft is now with Holy cross Medical center, Fort Lauderdale, Fla, and Dr. Sheth, with St. Mary's Hospital, Rhinelander, Wis.)

Reprint requests to Frank C. Astor, MD, University of Miami School of Medicine, PO Box 016960 (D-48), Miami, FL 33101.