Printer Friendly

Histomorphological spectrum of salivary gland tumors in a tertiary care hospital--A retrospective study.

Introduction

Salivary gland tumors account for 3-10% of the neoplasms of the head and neck region. [1,2] Global incidence of salivary gland tumors is 0.4-13.5 per 100,000 persons annually. [3-5] Approximately 80% of the salivary gland tumors are found in the parotid gland and 10-15% in the submandibular gland. [6] Around 80% of parotid tumors and 50% of submandibular tumors are benign. [7] Salivary gland tumors are observed in all ages but the highest incidence is observed in 3rd and 4th decades for benign tumors and 4th and 5th decades for malignant tumors. [8] Salivary gland tumors can show a striking range of morphological diversity between different tumor types and sometimes within an individual tumor mass. Hence, it is important to identify various histomorphological patterns and classify them accordingly. The aim of this study was to recognize various histomorphological patterns of salivary gland tumors, their frequency, age, and site distribution.

Material and Methods

The data for the present study was obtained from a tertiary care hospital, from July 2012 to June 2014. Information regarding age, gender, tumor location and tumor size were determined for each salivary gland tumor type. The frequencies of different benign and malignant salivary gland tumors in both major and minor glands were identified. All the biopsy specimens were fixed in 10% formalin, then processed into paraffin embedded sections and stained with hematoxylin and eosin (HE). The histopathology of all tumors was reviewed and classified according to the World Health Organization (WHO) histological typing of salivary gland tumors.

Result

Out of 96 cases, 60 (62.5%) were benign and 36 (37.5%) were malignant, representing a ratio of 1.6:1. The highest incidence of benign tumors was in the 3rd and 4th decade, whereas for malignant tumor it was the 4th and 5th decade of life. Male:female ratio was 1.6:1. The most common site of occurrence for both benign and malignant tumors was the parotid gland.

Among all benign salivary gland tumors, pleomorphic adenoma (Figure 1) was the most common histologic type followed by Warthin's tumor (Figure 2). Mucoepidermoid carcinoma (36.1%) was the most common among the malignant salivary gland tumors. Parotid was the most common site of occurrence for mucoepidermoid carcinoma followed by minor salivary glands and submandibular gland. The submandibular gland was the most common site of occurrence for adenoid cystic carcinoma (Figure 4).

The commonest malignant tumor of the parotid (27.8%) and the minor salivary glands (8.3%) was mucoepidermoid carcinoma (Figure 3). In the submandibular gland, the most common malignant salivary gland tumor was adenoid cystic carcinoma (13.9 %).

DISCUSSION:

In the present study, out of 96 cases of salivary gland tumors, 60 (62.5%) were benign and 36 (37.5%) were malignant. Mean age observed was 43.8 years with an age range of 12-75 years. Benign salivary gland tumors were more common in the age group of 31-40 years and the peak age incidence observed for malignant salivary gland tumors was 41-50 years. A male preponderance was noted with a male:female ratio of 1.6:1. Parotid was the commonest site of neoplasia (77.1%) in this series followed by submandibular gland (17.7%) and minor salivary glands (5.2%). In the present study, pleomorphic adenoma was the most common benign salivary gland tumor at all locations. Out of total 38 pleomorphic adenomas in our study, the majority occurred in the parotid gland (N=29; 48.3%) followed by submandibular gland (N=7; 11.6%) and minor salivary glands (N=2; 3.3%). Out of all reported cases of pleomorphic adenoma, 24 were males and 12 were females with a male to female ratio of 2:1. Out of 12 cases reported as Warthin tumor, the majority involved parotid gland (N=9; 15%) followed by submandibular gland (N=3; 5%). Mucoepidermoid carcinoma was more common in the parotid gland (N=10; 27.8%) followed by minor salivary glands (N=2; 8.3%) and submandibular gland (N=1; 2.7%). The most common malignant salivary gland tumor observed in submandibular salivary gland was adenoid cystic carcinoma accounting for 27.7% of all malignant tumors. Mucoepidermoid carcinoma was the most common malignant salivary gland tumor constituting 13 cases (36.1%) of all malignant salivary gland tumors in the present series.

Chatterjee et al. observed a large number of benign cases in the 3rd decade followed by 4th decade. [9] Malignancy reported in his study was predominant in the 5th decade. The male:female ratio is in agreement with series reported by Potdar GG et al., [10] Spiro et al. [11] and Gore et al. [12] In the majority of case series, pleomorphic adenoma was the most common benign salivary gland tumor encountered in all salivary glands. [9,10,13,15] One case of lipoma was seen in our study. Literature review reveals that these are rare neoplasms of the parotid. [16] Schwannoma presenting as primary salivary gland neoplasm is thought to arise from the radicals of the facial nerve. We observed one case of schwannoma, affecting parotid gland. Mucoepidermoid carcinoma was reported to be the most common malignant salivary gland tumor of parotid by Richardson et al [13] and Spiro et al. [11] Carcinoma ex pleomorphic adenoma is an infrequent aggressive malignancy that is believed to evolve from a pre-existing benign adenoma. We found 3 cases (8.3 %) of carcinoma ex-pleomorphic adenoma of the parotid gland among malignant tumors. Polymorphous low-grade adenocarcinoma (PLGA) occurs almost exclusively in the minor salivary gland and its origin in a major salivary gland is considered rare. Although, several reports have described PLGA of the parotid gland, we did not find any case of PLGA in this study. Primary squamous cell carcinoma of the salivary gland is rare. Batsakis et al indicated that the true incidence to be 0.3-1.5%. We found 2 cases (5.5%) of squamous cell carcinoma in parotid gland in our series.

Salivary gland tumors can show a striking range of morphological diversity between different tumor types and sometimes within an individual tumor mass. In such cases, it is difficult to classify them correctly on histopathological grounds only.

Conclusion

Salivary gland tumors are relatively rare. Benign salivary gland tumors are more common than malignant ones. There is male preponderance in the incidence of salivary gland tumors. The Parotid gland is the commonest site for occurrence of salivary gland tumors. Pleomorphic adenoma is the most frequently encountered tumor among all salivary gland tumors. Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands and parotid is the commonest site for the same. Histopathological examination is mandatory in the diagnosis of salivary gland tumors as they have a very wide spectrum of morphological patterns.

DOI: 10.5455/ijmsph.2017.25072016603

References

[1.] Ansari MH. Salivary gland tumors in an Iranian population: a retrospective study of 130 cases. Journal of Oral and Maxillofacial Surgery 2007;65:2187-94.

[2.] Jones AV, Craig GT, Speight PM, Franklin CD. The range and demographics of salivary gland tumors diagnosed in a UK population. Oral Oncol 2008;44:407-17.

[3.] Ma'aita JK, Al-Kaisi N, Al-Tamimi S, and Wraikat A. Salivary gland tumors in Jordan: a retrospective study of 221 patients. Croat Med J 1999;40:539-42.

[4.] Jaber MA. Intraoral minor salivary gland tumors: a review of 75 cases in a Libyan population. Int J Oral Maxillofac Surg 2006; 35:150-4.

[5.] Tian Z, Li L, Wang L, Hu Y, and Li J. Salivary gland neoplasms in oral and maxillofacial regions: a 23-year retrospective study of 6982 cases in an eastern Chinese population. Int J Oral Maxillofac Surg 2010;39:235-42.

[6.] Bataskis J. G. and Regezi J. A. The pathology of head and neck tumors: salivary glands, part 1. Head Neck Surg1978;1:59-68.

[7.] Paparella's Otolaryngology: Vol. III, 3rd Edition, W. B. Saunders. 1991; 20: 2099pp.

[8.] Ahrnad S, Lateef M, Ahmad R. Clinicopathological study of primary salivary gland tumors in Kashmir. JK-Practitioner 2002; 9:231-3.

[9.] Chatterjee MT and Panda PK. A Pathological study of benign and malignant tumors of salivary glands; MJAFI 2000;56:282-6. [URL: http://medind.nic.in/maa/t00/i4/maat00i4p282.pdf]

[10.] Potdar GG, Paymaster JC. Tumors of salivary glands. Am J Surg1969;118:440-7.

[11.] Spiro RH, Huvos AG, Strong EW. Cancer of the parotid gland: a clinicopathologic study of 288 primary cases. Am J Surg 1975;130:452-9.

[12.] Gore DO, Annamunthodo H, Harland A. Tumors of salivary gland origin. Surg Gynecol Obstet 1964; 119:1290-6.

[13.] Richardson GS, Dickason WL, Gaisford JC, et al. Tumors of salivary glands; An analysis of 752 cases. Plastic Reconstr Surg 1975;55:131.

[14.] Vergas PA, Gerhard R, Vergilius J. F, Filiho A and de Castro IV. Salivary gland tumors in Brazillian population: A retrospective study of 124 cases. Rev. Hosp. Clin. Fac. Med. S. Paulo 2002;57:271-6.

[15.] Nagarkar NM, Bansal S, Dass A, Singhal SK, Mohan H. Salivary gland tumors- Our Experience. Indian J Otolaryngol Head Neck Surg2004;56:32-4.

[16.] Muzaffar S, Kayani N, Hasan SH. Partoid gland lipoma: a rare entity. J Pak Med Assoc 1996;46:262-3.

Nirali S. Amin, Smita A. Shah, Shreedhan G. Prajapati, Hansa M. Goswami

Department of Pathology, B.J. Medical College, Ahmedabad, Gujarat, India.

Correspondence to: Nirali S. Amin, E-mail: nirali.no1@gmail.com

Received July 25, 2016. Accepted August 13, 2016

Caption: Figure 1: Pleomorphic adenoma showing both epithelial and mesenchymal components (HE stain, X200)

Caption: Figure 2: Warthin's tumor. The papillary projection exhibits oncocytic lining cells and an underlying lymphoid stroma (HE stain, X 200).

Caption: Figure 3: Low-grade mucoepidermoid carcinoma showing glandular spaces with mucous secreting cells and intermediate cells (HE stain, X200).

Caption: Figure 4: Typical adenoid cystic carcinoma showing a cribriform pattern (HE stain, X 200).
Table 1: Age wise distribution of salivary gland tumors

Aqe qroup      Benign   Malignant   No. of cases
(years)        tumors    tumors

<20                3           1          4
21-30              8           1          9
31-40             20           6         26
41-50             18          14         32
51-60              6           8         14
61-70              3           4          7
>70                2           2          4
Total             60          36         96

Table 2: Distribution of salivary gland tumors according to sex and site

Sex        Total        Parotid gland        Submandibular gland

                     Benign    Malignant     Benign    Malignant

Male        61         31         15           6           5
Female      35         18          9           2           3

Sex             Minor salivary glands

                Benign    Malignant

Male              2           2
Female            1           2

Table 3: Distribution of benign tumors in salivary glands

Tumor type            Parotid   Submandibular   Minor salivary   Total
                       gland        gland           gland

Pleomorphic adenoma     29            7               2           38
Warthin's tumor          9            3               --          12
Monomorphic adenoma      3            1               --           4
Myoepithelioma           3           --               --           3
Basal cell adenoma       1           --               --           1
Schwannoma               1           --               --           1
Lipoma                   1           --               --           1

Table 4: Distribution of malignant tumors in salivary glands

Tumor type                               Parotid gland   Submandibular
                                                             gland

Mucoepidermoid carcinoma                      10               1
Adenoid cystic carcinoma                       4               5
Carcinoma ex- pleomorphic adenoma              3              --
Adenocarcinoma NOS                             2              --
Unclassified malignant tumor                   2              --
Basal cell carcinoma                           2              --
Squamous cell carcinoma                        2              --
Metastatic undifferentiated carcinoma          1              --
Acinic cell carcinoma                          1              --
Polymorphous low-grade adenocarcinoma         --              --

Tumor type                               Minor salivary   Total
                                             glands

Mucoepidermoid carcinoma                       2           13
Adenoid cystic carcinoma                       1           10
Carcinoma ex- pleomorphic adenoma              --           3
Adenocarcinoma NOS                             --           2
Unclassified malignant tumor                   --           2
Basal cell carcinoma                           --           2
Squamous cell carcinoma                        --           2
Metastatic undifferentiated carcinoma          --           1
Acinic cell carcinoma                          --           1
Polymorphous low-grade adenocarcinoma          --          --
COPYRIGHT 2017 Dipika Charan
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Original Research
Author:Amin, Nirali S.; Shah, Smita A.; Prajapati, Shreedhan G.; Goswami, Hansa M.
Publication:International Journal of Medical Science and Public Health
Article Type:Report
Date:Feb 1, 2017
Words:1877
Previous Article:A comparative study of sevoflurane and propofol for laryngeal mask airway insertion.
Next Article:Anemia in patients with type II diabetes mellitus with and without diabetic retinopathy.
Topics:

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters