Original Articles

Profile Of Pleomorphic Adenoma In A Tertiary Care Teaching Hospital In Sub-himalayan Valley

Corresponding Author Dr. Arnab Ghosh
Pathology, Manipal College of Medical Sciences, - Nepal
Submitting Author Dr. Arnab Ghosh
Pathology, Manipal College of Medical Sciences, Nepal

Plus Speciality:

PATHOLOGY

Keywords:

Pleomorphic adenoma, salivary gland, parotid.

How to cite the article:

Ghosh A, Ghartimagar D, Sathian B, Narasimhan R, Talwar O. Profile Of Pleomorphic Adenoma In A Tertiary Care Teaching Hospital In Sub-himalayan Valley. WebmedCentral plus PATHOLOGY 2014;5(3):WMCPLS00337
doi: 10.9754/journal.wplus.2014.00337

Copyright:

This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Submitted on: 18 Feb 2014 09:46 AM
Accepted on: 28 Feb 2014 07:05 AM
Published on: 19 Mar 2014 12:24 PM

Abstract


Introduction: Salivary glands are divided into major and minor ones. Salivary gland tumors comprise only 3% of all neoplasms of head and neck region and show diverse histology. Pleomorphic adenoma (PA), also known as benign mixed tumor, is the most common salivary gland neoplasm accounting for 60% of all benign salivary gland tumors. The aim of the study is to analyze all the records of cases reported as PA

Materials and methods: This study is a hospital based retrospective study carried out in the Department of Pathology, Manipal Teaching Hospital. All the records and slides of cases reported as PA on histopathology in the time period from Jan 2003 to Dec 2012 were retrieved and analyzed. Descriptive statistics and testing of hypothesis were used for the data analysis.

Results: A total of 82 PA were reported in the study period. 74 cases were from major salivary glands and parotid (54 cases) was the commonest site. Left side was marginally more involved  than right side. The mean size of tumor was 4.5 cm and all intra-oral lesions (14 cases) were smaller than 2 cm. The commonest age group was 31-40 years (22,26.8%) followed by 21-30 years (20,24.4%) and 41-50 years (14,17%) Females were affected more in a ratio of 1:1.6. On histology, all cases showed a mixture of epithelial and myoepthelial components. Among different  types  of epithelial cells, plasmacytoid cells were the most common type. Most of the patients presented with painless swelling and 3 cases presented with dull ache. Cases in nasal cavity and orbit presented with nasal stuffiness and unilateral exophthalmos. All the cases were treated by surgical excision and were followed up for a period of 8 months to 2 years. None of the patients showed any recurrence.

Conclusion: Most of the findings in our series were similar to other previously published international literature. However involvement of younger patients, left side and minor salivary glands were found to be more in the current study.

Introduction


Salivary glands are classified into the major glands namely parotid, submandibular and sublingual glands and the minor ones which are present in the lips, gingiva, floor of the mouth, cheek, palate, tongue and oropharynx. Salivary glands may give rise to various inflammatory  and neoplastic conditions- more than 30 different types of neoplastic entities have been  reported despite of its relatively simple histology1. Salivary gland tumors are rare comprising less than 3% of all neoplasms of head and neck region and are known by their diverse  histological features2-5 Pleomorphic adenoma (PA), also known as benign mixed  tumor,  is the most common salivary gland neoplasm accounting for 60% of all benign salivary gland tumors6,7 It represents 60 to 73% of parotid gland tumors, 12% to 60% of submandibular gland tumors and 14% to 70% of minor  salivary  gland  tumors8-10 It is  composed of  epithelial and myoepithelial components arranged in varied microscopic patterns as well as areas of mesenchymal differentiation1 The aim of the current study was to review and analyze the records of patients diagnosed with PA on histopathology in a single institution.

Materials and methods


Design: This study is a hospital based retrospective study carried out in the Department of Pathology, Manipal Teaching Hospital. All the records and slides of cases reported as PA on histopathology in the time period from Jan 2003 to Dec 2012 were retrieved and analyzed.

Outcome Variable: Main outcome variable was Pleomorphic adenoma (PA).

Explanatory Variable: Age (5) were the explanatory variables at individual level.

Sample size calculation: For 95%  confidence  interval  and,  significance  level  α  =5%,  P  =  85%,  Q  =  15%, allowable error = 10%, required sample size was 68. P = percentage of PA. Q= 100-P. In the pilot study done prior to the original study with 20 patients11

Ethical committee approval: Prior to the study, approval was taken from the institutional ethical committee. The study was conducted in accordance to latest version of the Declaration of Helsinki.

Data management and statistical analysis: The data collected was analyzed using Excel 2003, R 2.8.0 Statistical Package for the Social Sciences (SPSS) for Windows Version 16.0 (SPSS Inc; Chicago, IL, USA) and EPI Info 3.5.1 Windows Version.

The Z test was used to observe the difference between different variables and chi-square test was used to find out the relationship between two variables. p< 0.05 was considered as statistically significant12

Results


We had a total of 124 cases of salivary gland neoplasm reported in the mentioned study period , of which 82 cases were diagnosed as PA. The sites, frequency, percentage, side or laterality, size of the tumor and gender distribution are shown in Table 1, while Table 2 summarizes the age distribution of all cases as well as its correlation with gender and the sites involved.


Table 1: Distribution of site, number, size and gender of pleomorphic adenoma


Table 2: Age distribution of pleomorphic adenoma

Site

Major salivary glands were involved in 74 cases while the rest 8 cases were from minor salivary glands and other sites. Parotid was the commonest site with 54 cases (65.9%) followed  by  submandibular (12,14.6%), sublingual  (8,9.8%), palate (3,3.6%), cheek(2,2.4%) and lip (1,1.2%). We also reported one case each from nasal cavity and from lacrimal gland in orbit.

Side

Overall, left side was more common than right side in our data. Among only the cases of the major salivary glands, 40 cases were on the left side compared to 34 cases on the right side. Parotid, submandibular and sublingual glands had 28, 7 and 5 cases on left side compared to 26, 5 and 3 cases on right side respectively

Size

The size range was from 1 cm to 7 cm with a mean of 4.5 cm. We had classified the tumors in 3 categories viz.5 cm. Thirty nine cases were in the >5 cm group followed by  27 cases in 2-5 cm group and 16 cases in

Age

The age range was from 7 years to 68 years with a mean of 36.2 years. The commonest affected age group was 31-40 years (22,26.8%) followed by 21-30 years (20,24.4%) and 41-50 years (14,17%).



Sex

Females were affected more in our series. We had a total of 32 cases in males and 52 cases in females with a male female ratio of 1:1.6. Among the cases involving the three major salivary glands, 30 were males while 44 were females (1:1.5).


Figure 1: Gross features showing a well demarcated tumor with characteristic gelatinous cut surface.


Figure 2: Micro photograph showing presence of plasmacytoid and spindle cells as well as chondromyxoid stroma,H&Estain,100x.


Figure 3: Micro photograph showing areas with plasmacytoid cells and chondromyxoid stroma,H&Estain,400x; inset showing plasmacytoid cells H&Estain,1000x.

Pathology

All cases in our study showed a well demarcated tumor with gelatinous cut surface on gross (Fig 1) and a mixture of epithelial and myoepithelial cells on microscopy. All cases showed presence of plasmacytoid and spindle cells as well as chondromyxoid stroma  (Fig 2,3). In general, nuclear features were bland with absent or inconspicuous nucleoli and mitosis are mostly not seen.

Clinical feature

Most of the patients presented with painless swelling in the affected area with a variable duration of 5 months to 7 years (mean 13 months). 3 patients complained of dull ache along with swelling. All patients with PA in oral cavity presented earlier compared to those with PA in major salivary glands. The two cases with involvement of  nasal cavity and orbit presented with nasal stuffiness and unilateral exophthalmos.

Discussion


Site

PA is a slow growing tumor affecting most commonly the parotid gland. In a series by Subhashraj et al, out of 363 cases of PA, 56% were in parotid followed by 20% in submandibular gland6 Everson JW et al also, in an analysis of 1408 PA, found parotid to be  the commonest site followed by submandibular gland8 Similarly in our study, parotid was  involved in majority of cases (65.9%), followed by submandibular gland (14.6%) and sublingual gland (9.8%). In separate studies by Ito FA, Friedrich RE and Chidzonga MM, minor salivary gland was found to be the second commonest site next to parotid gland2,13,14 Ito FA and Friedrich RE did not report any case in sublingual glands and Friedrich RE had 16% of cases in palate2,13 In contrast, we had 8 cases (9.8%) in sublingual gland and had only 3 cases (3.7%) in palate.

Side

In the studies by Al-Khtoum N and Friedrich RE, laterality of the tumors were conspicuous– especially in parotid gland3,13 Both studies showed more involvement of right side (65.8%,  72.5% respectively) in contrast to our study which showed marginally more cases on left side (52.4%).

Size

Majority of cases (63/66) in parotid and submandibular glands presented with tumors larger than 2 cm while majority of intra-oral cases (13/14) presented with tumor smaller than 2 cm. This was perhaps because intra-oral lesions gave rise to early discomfort and were noticed early.

Age & Sex

Female patients are known  to  be  more  affected  than  males1,8,14-19 The  peak incidence occurs in 4th and 5th decades8,14,17,18 In the present study, females were more affected  in a ratio of 1:1.6. However in minor salivary glands the sex ratio was insignificant. In  a study among Jordonian patients no gender predilection could be elicited3 The maximum number of cases we reported were in third and fourth decades, which is younger compared to other literatures.

Pathology

Though microscopically PA may show great variations, the main diagnostic feature is the presence of both epithelial and mesenchymal like tissues. Their proportion has been used to  subclassify PA, however no therapeutic or prognostic significance could be found1 The  different types of cells seen include plasmacytoid, spindle, cuboidal, basaloid, squamous, clear, mucous and oncocytic cells1,2 The commonest cell type in our study was plasmacytoid  as in other study2 The  epithelial component may form trabeculae, ducts, cysts, or  predominantly solid areas. Mesenchymal component classically show chondromyxoid stroma with  or without areas of calcifications and hyalinization.

Clinical feature & Follow up

All the cases were treated by complete surgical excision which is the treatment of choice. PA can show local recurrence and give rise to carcinoma both in minor and major salivary glands especially in long standing and recurrent cases13,20-23 However in our study all the cases were followed up for a variable period of 8 months to 2 years and none of them showed any recurrence.

Conclusion


Most of the findings in our series were similar to other previously published international literature. However involvement of younger patients, left side and minor salivary glands were found to be more in the current study.

 

 

 

References


1. Ellis GL, Auclair PL: Tumors of the salivary glands, Atlas of Tumor Pathology. Third Series, Fascicle 17.Washington, DC, Armed Forces Institute of Pathology, 1996.
2. Ito FA, Jorge J, Vargas PA, Lopes MA. Histopathological findings of pleomorphic adenomas  of  the  salivary  glands. Med Oral Patol Oral Cir Bucal. 2009 Jan 1;14 (2):E57-61.
3. Al-Khtoum N, Qubilat AR, Al-Zaidaneen S, Al Mefleh S, Al-Qudah A. Clinical characteristics of pleomorphic adenoma of salivary glands among Jordanian patients.J Pak Med Assoc. 2013 Mar;63(3):358-60.
4. Van der Wal JE, Leverstein H, Snow GB, Kraaijenhagen HA, Van der Waal I. Parotid gland  tumors: histologic reevaluation and reclassification of 478 cases. Head Neck.1998;20:204-7.
5. Forty MJ, Wake MJ. Pleomorphic salivary adenoma in an adolescent. Br Dent J 2000; 188: 545-6.
6. Subhashraj K. Salivary gland tumours: a single institution experience in India. Br J Oral Maxillofac Surg 2008; 46: 635-8.
7. Paris J, Facon F, Chrestian MA, Giovanni A, Zanaret M. Pleomorphic adenoma of the parotid: histopathologic study. Ann Otolaryngol Chir Cervicofac 2004; 121: 161-6.
8. Eveson JW, Cawson RA. Salivary gland tumours. A review of  2410 cases with particular  reference to histological types, site, age and sex distribution. J Pathol. 1985;146:51-8.
9. Spiro RH. Salivary neoplasms: overview of a 35-year experience with 2,807 patients. Head Neck Surg. 1986;8:177-84.
10. Ito FA, Ito K, Vargas PA, De Almeida OP, Lopes MA. Salivary gland tumors in a Brazilian population: a retrospective study of 496 cases. Int J Oral Maxillofac Surg. 2005;34:533-6.
11. Sathian B, Sreedharan J, Baboo NS, Sharan K, Abhilash ES, Rajesh E. Relevance of  Sample Size Determination in Medical Research. Nepal J Epidemiol 2010; 1(1):4–10.
12. Sathian B. Methodological Rigors in Medical Journals from Developing Countries: An Appraisal of the Scenario in Asia. Nepal J Epidemiol 2011; 1(5): 141-3.
13. Friedrich RE, Li L, Knop J, Giese M, Schmelzle R.Pleomorphic adenoma of the salivary glands: analysis of 94 patients.Anticancer Res. 2005 May-Jun;25(3A):1703-5.
14. Chidzonga MM Perez VML, Alvarez ALP. Pleomorphic adenoma of the salivary glands:  clinicopathologic study of 206 cases in Zimbabwe. Oral Surg Oral Med Oral Pathol Oral Radiol Oral Endod. 1995;79:747-9
15. Ayoub  OM, Bhatia K, Mal RK. Pleomorphic adenoma of the parotid gland: Is long-term follow-up needed?. Auris Nasus Larynx 2002;29: 283-5.
16. Lingam  RK, Daghir AA, Nigar E, Abbas SA, Kumar M. Pleomorphic adenoma (benign mixed tumour) of the   salivary glands: its diverse clinical, radiological, and histopathological presentation. Br J  Oral Maxillofac Surg 2011;49:14-20
17. Ledesma-Montes  C, Garces-Ortiz M. Salivary gland tumours in a Mexican sample. A retrospective study. Med Oral 2002; 7: 324-30
18. Takahama A Jr, Da Cruz Perez DE, Magrin J, De Almeida OP, Kowalski LP. Giant pleomorphic   adenoma of the parotid gland.Med Oral Patol Oral Cir Bucal 2008; 13: E58-60.
19. Williams NP, Boyd DL, Choy L, Hanchard B. Salivary gland lesions: A Jamaican perspective. West Indian Med J. 2001;50:62-5
20. Batsakis JG: Recurrent mixed tumours. Ann Otol Rhinol Laryngol 1986; 95: 543-4.
21. Freeman SR, Sloan P, de Carpentier J. Carcinoma ex pleomorphic adenoma of the nasal   septum with adenoid cystic and squamous carcinomatous differentiation. Rhinology 2003; 41: 118-21.
22. To EW, Tsang WM, Tse GM. Mucoepidermoid carcinoma ex pleomorphic adenoma of the  submandibular gland. Am J Otolaryngol 2003; 24: 253-7.
23. Rowley H, Murphy M, Smyth D, O'Dwyer TP. Recurrent pleomorphic adenoma: uninodular versus multinodular disease. Ir J Med Sci 2000; 169: 201-3.

Source(s) of Funding


None

Competing Interests


None

Prepublication Reviews

MSID: WMCPLS00337 &n...
Posted by Anonymous reviewer on 01 Feb 2014 12:01:09 PM GMT

Dear Sir

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we have edited the article and one photo has been added according to reviewer\'s comments .

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Changes made are in red fonts

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looking forward for the publicationView more
Responded by Dr. Arnab Ghosh on 01 Jan 1970 12:00:00 AM GMT

This article is well...
Posted by Anonymous reviewer on 29 Dec 2013 11:52:34 PM GMT

Dear Reviewers

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Thanks for your minor comments

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We have added legends for the 2 figures and also added it in the text ( in Result portion under the paragraph \"pathology\" ) 

... View more
Responded by Dr. Arnab Ghosh on 01 Jan 1970 12:00:00 AM GMT