Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contact Us Login 
An Official Publication of the Indian Association of Oral and Maxillofacial Pathologists

  Table of Contents    
Year : 2013  |  Volume : 17  |  Issue : 1  |  Page : 95-97

Sialolipoma of the parotid gland: Case report with literature review comparing major and minor salivary gland sialolipomas

1 Department of Pathology, The University of Tennessee Health Science Center, Memphis, TN, USA
2 Department of Otolaryngology, The University of Tennessee Health Science Center, Memphis, TN, USA

Date of Web Publication18-Apr-2013

Correspondence Address:
Nadeem Zafar
Department of Pathology, 930 Madison Ave, 5th Floor, Memphis, TN 38103
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0973-029X.110687

Rights and Permissions



Sialolipoma is a rare tumor found within both major and minor salivary glands. Here we discuss sialolipoma of the parotid gland and briefly review the English literature. Including our case, a total of 35 sialolipomas have been reported, 18 within major salivary glands and 17 within minor salivary glands. Major gland sialolipomas most often are presented in the parotid gland (77%) and those from minor glands were most often seen in the palate (41%). All lesions were well circumscribed and contained mature adipose tissue intimately admixed with benign salivary gland components. Ductal dilatation was found in 100% of minor salivary gland sialolipomas but in only 28% of major salivary gland tumors. Nerve entrapment has also rarely been noted in major salivary glands (14%) whereas myxoid degeneration has been identified in rare minor salivary glands tumors (13%). Treatment is surgical excision and is curative with no reports of recurrence.

Keywords: Lipoma, major salivary gland, minor salivary gland, parotid gland, sialolipoma

How to cite this article:
Qayyum S, Meacham R, Sebelik M, Zafar N. Sialolipoma of the parotid gland: Case report with literature review comparing major and minor salivary gland sialolipomas. J Oral Maxillofac Pathol 2013;17:95-7

How to cite this URL:
Qayyum S, Meacham R, Sebelik M, Zafar N. Sialolipoma of the parotid gland: Case report with literature review comparing major and minor salivary gland sialolipomas. J Oral Maxillofac Pathol [serial online] 2013 [cited 2023 Feb 5];17:95-7. Available from: https://www.jomfp.in/text.asp?2013/17/1/95/110687

   Introduction Top

Benign fatty tumors of parotid gland (lipomas) are very unusual, accounting for less than 0.5% of all parotid tumors. Despite infrequent numbers, numerous histological variants of salivary gland lipoma have been described. Sialolipoma, a new distinct variant, is characterized by proliferation of mature adipocytes with secondary entrapment of normal salivary gland elements. [1] A review of English scientific literature (PubMed) indicates 34 reported cases of sialolipoma, including 13 cases (38%) arising in the parotid gland, [2],[3],[4],[5] followed by 7 cases (21%) in the palate. Here we report the 14 th case of parotid gland sialolipoma.

   Case Report Top

A 69-year-old White male presented to the otolaryngology clinic with a right parotid mass of approximately 5-year duration, without history of xerostomia, salivary pain, odynophagia, dysphagia, weight loss, mouth pain, facial weakness, hemoptysis, infection, or conditions associated with immunodeficiency. Significant medical history included Type II diabetes, prostatic cancer, hypercholesterolemia, hypertension, and back pain. On examination, a 2×2 cm soft mass was palpated over the right parotid bed, which was nontender and mobile. Computed tomography (CT) scan showed a 1.9×2.3 cm encapsulated hypodense, hypoenhancing mass in the anterosuperior aspect of the right parotid gland [Figure 1]. The density of the mass was consistent with fat with intralesional heterogeneity. Fine needle aspiration was performed twice, but was nondiagnostic. The patient was treated surgically with a right superficial parotidectomy with facial nerve preservation.
Figure 1: Axial CT neck showing a 19 × 23 mm well encapsulated mass in right anterior parotid bed. It has fat-like enhancement

Click here to view

On gross pathologic examination, a 2.7×2.2×1.5 cm well-circumscribed pale, firm soft tissue mass abutting the anterior margin of the specimen was noted. On microscopy a well-delineated lesion was observed, composed predominantly (75-90%) of mature adipose tissue with interspersed aggregates of oncocytic cells in small acini and clusters. A diagnosis of sialolipoma was rendered [Figure 2] , [Figure 3] , [Figure 4].
Figure 2: Image showing well demarcated mass with fat and admixed epithelial elements. (H and E, ×40)

Click here to view
Figure 3: Image showing salivary gland elements with oncocytic change intermingled with mature adipose tissue, separated by fibrous capsule from normal parotid gland parenchyma. (H and E, ×200)

Click here to view
Figure 4: Image showing lesion with lymphocytic infiltrate and oncocytic metaplasia in a background of mature fat cells. (H and E, ×100)

Click here to view

   Discussion Top

Sialolipoma is a relatively new histological variant of lipoma typified by benign salivary gland parenchyma intimately admixed with mature adipose tissue. [1] Our patient's clinical presentation of painless, slow growing, mobile mass with the microscopic findings of an encapsulated lesion with 75-90% of mature adipose tissue entrapping benign acinar and ductal cells and small lymphoid aggregates was consistent with the rendered diagnosis of sialolipoma. [1] Oncocytic metaplasia and mild to moderate lymphocytic infiltrate have previously been mentioned. [1],[5],[6] Glandular atrophy, periductal fibrosis, ductal dilatation and peripheral nerve involvement are additional features that have been reported in prior cases, [6] but were not present in our patient.

In a tabulated analysis of 35 cases (including our own), we compared the features of sialolipoma within major and minor salivary glands [Table 1]. [1],[2],[3],[4],[5],[6] The typical clinical presentation was that of a painless slow-growing mass, most commonly in parotid gland or palate. While the age distribution for major salivary gland sialolipomas was diverse (including four pediatric cases), minor salivary gland tumors were reported in adults only. Major salivary gland lesions were larger compared with minor salivary gland lesions, likely related to more room for the lesion to grow within the larger salivary gland prior to being noticed.
Table 1: Comparison of sialolipomas originating in major and minor salivary glands

Click here to view

Histopathological features were also compared between major and minor salivary gland sialolipomas. Most lesions in either group were well circumscribed and contained mature fat intimately admixed with benign salivary gland components. Nerve entrapment was noted only in major salivary glands whereas myxoid degeneration was observed only in minor salivary gland tumors.

Akrish et al. [5] hypothesized that pathogenesis of sialolipoma may be associated with some form of salivary gland dysfunction, leading to altered salivary gland configuration. This concept is favored microscopically by replacement of the normal salivary gland tissue with mature adipose tissue admixed with atrophic salivary glandular elements, and/or chronic ductal epithelial changes (oncocytic metaplasia, fibrosis and lymphocytic infiltrate). Presence of similar histological findings in other conditions related to salivary gland dysfunction, for example, sialadenosis, senile, and reactive salivary gland changes further supports the above argument. [5]

The differential diagnosis of sialolipoma includes lipomatous lesions such as lipomatosis, lipoadenoma, and pleomorphic adenoma with an extensive fat constituent. CT or magnetic resonance imaging can be helpful in narrowing the differential diagnosis and are superior to ultrasonography in defining exact location and texture of the lesion. Fine needle aspiration, which is the first line procedure in diagnosing major salivary gland lesions is of little help, as its accuracy is less than 50% in lipomatous tumors. [3],[6],[7] Treatment of choice is surgical excision for both major and minor salivary glands sialolipomas. There are no reports of recurrence. [2]

Salivary gland neoplasms have a vast differential diagnosis. Physicians should be mindful of the possibility of sialolipoma, especially when CT scanning shows a well circumscribed fat-like tissue within the parotid gland.

   References Top

1.Nagao T, Sugano I, Ishida Y, Asoh A, Munakata S, Yamazaki K, et al. Sialolipoma: A report of seven cases of a new variant of salivary gland lipoma. Histopathology 2001;38:30-6.  Back to cited text no. 1
2.Nonaka CF, Pereira KM, de Andrade Santos PP, de Almeida Freitas R, da Costa Miguel MC. Sialolipoma of minor salivary glands. Ann Diagn Pathol 2011;15:6-11.  Back to cited text no. 2
3.Sato K, Gotoh C, Uchida H, Kawashima H, Yoshida M, Kitano Y, et al. Sialolipoma of the submandibular gland in a child. J Pediatr Surg 2011;46:408-10.  Back to cited text no. 3
4.de Moraes M, de Matos FR, de Carvalho CP, de Medeiros AM, de Souza LB. Sialolipoma in minor salivary gland: Case report and review of the literature. Head Neck Pathol 2010;4:249-52.  Back to cited text no. 4
5.Akrish S, Leiser Y, Shamira D, Peled M. Sialolipoma of the salivary gland: Two new cases, literature review, and histogenetic hypothesis. J Oral Maxillofac Surg 2011;69:1380-4.  Back to cited text no. 5
6.Okada H, Yokoyama M, Hara M, Akimoto Y, Kaneda T, Yamamoto H. Sialolipoma of the palate: A rare case and review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:571-6.  Back to cited text no. 6
7.Doðan S, Can IH, Unlü I, Süngü N, Gönültaþ MA, Samim EE. Sialolipoma of the parotid gland. J Craniofac Surg  Back to cited text no. 7


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1]

This article has been cited by
1 A case of lipoma of the parotid gland: Distinguishing the tumor from the fatty parotid gland by the injection of indigo carmine into Stensen’s duct for appropriate enucleation
Toru Sato, Chika Terada, Shinji Ide, Seiko Tatehara, Kazuhito Satomura
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology. 2021; 33(4): 416
[Pubmed] | [DOI]
2 A rare case of recurrent congenital sialolipoma of parotid gland in a 3-year-old child: A case report and review of literature
Khadija Salama, M. Lahjaouj, B. Merzouqi, Youssef Oukessou, Sami Rouadi, Reda Abada, Mohamed Roubal, Mohamed Mahtar, Dounia Jamaa, Mehdi Karkouri
International Journal of Surgery Case Reports. 2021; 81: 105784
[Pubmed] | [DOI]
3 Giant submandibular sialolipoma masquerading as huge goitre: a case report
Sentilnathan Subramaniam, Syamim Johan, Firdaus Hayati, Chiak Yot Ng, Nornazirah Azizan, Jitt Aun Chuah, Irfan Mohamad
BMC Surgery. 2020; 20(1)
[Pubmed] | [DOI]
4 Sialolipoma of the Parotid Gland: An Uncommon Lipoma Variant of Salivary Gland
M. H. A. Ghafar, G. Ju Tuang, N. M. Y. Mohammad, Ch. Nadarajan, Baharudin Abdullah
Acta Medica Bulgarica. 2018; 45(1): 39
[Pubmed] | [DOI]
5 Sialolipoma of Minor Salivary Glands: Presentation of Five Cases and Review of the Literature with an Epidemiological Analyze
Elba Leyva Huerta,Daniel Quezada Rivera,Fernando Tenorio Rocha,José Luis Tapia,Javier Portilla Robertson,Luis Alberto Gaitán Cepeda
Indian Journal of Otolaryngology and Head & Neck Surgery. 2014;
[Pubmed] | [DOI]


Print this article  Email this article


    Similar in PUBMED
    Search Pubmed for
    Search in Google Scholar for
  Related articles
    Article in PDF (1,700 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

   Case Report
    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded319    
    Comments [Add]    
    Cited by others 5    

Recommend this journal

© Journal of Oral and Maxillofacial Pathology | Published by Wolters Kluwer - Medknow
Online since 15th Aug, 2007