14 June 2006 – Case of the Week #49


These cases can also be accessed by clicking on the Case of the Week button on the left hand side of our Home Page at www.PathologyOutlines.com.  This email is sent only to those who subscribe in writing or by email.  To view the images or references, you must click on the links in blue.


To subscribe or unsubscribe, email info@PathologyOutlines.com, indicating subscribe or unsubscribe to Case of the Week.  We do not sell, share or use your email address for any other purpose.  We also maintain two other email lists: to receive a biweekly update of new jobs added to our Jobs page, and to receive a monthly update of changes made to the website.  You must subscribe or unsubscribe separately to these email lists.


This Case is sponsored by Sakura Finetek, USA.  Leading the revolution in Pathology, the Tissue-Tek® Xpress® Rapid Tissue Processor is helping laboratories achieve new levels of productivity.  Enabling a continuous flow of up to 40 cassettes every 15 minutes, this system can process up to 120 specimens per hour.  The Xpress® allows for a balanced distribution of work throughout the day, eliminating bottlenecks and batches common with overnight processing.  Improved turnaround times, reduced waste, and increased productivity are just a few benefits this technology can offer your lab.  Results are the same or better than overnight processing.  Help your lab reach its full potential with the Tissue-Tek® Xpress® Rapid Tissue Processor.  For more information, contact Ms. Elise Green, Marketing Manager at 1-800-725-8723 extension 7873 or at egreen@sakuraus.com


We thank Dr. Juan Jose Segura Fonseca, Hospital San Juan de Dios, Costa Rica, for contributing this case.  We invite you to contribute a Case of the Week by sending an email to NPernick@PathologyOutlines.com with microscopic images (any size, we will shrink if necessary) in JPG or GIF format, a short clinical history, your diagnosis and any other images (gross, immunostains, EM, etc.) that may be helpful or interesting.  We will write the discussion (unless you want to), list you as the contributor, and send you a check for $35 (US) for your time after we send out the case.  Please only send cases with a definitive diagnosis. 


Case of the Week #49


Clinical history


A 68 year old woman was seen in the outpatient clinic because of difficulty in swallowing and sensation of a "large foreign body" in her throat, of several months duration.  On physical examination, a large, solid, pale yellow tumor was located in the soft palate.  Complete resection of a large lipoma-like tumor mass was performed.


Gross images: figure 1, figure 2


Microscopic findings:  On low power (figure 3), a tumor characterized by peripheral lipomatous tissue and central salivary gland elements with prominent dilation of ducts is seen.  In the periphery, there is a predominance of adipose tissue that looks like a lipoma (figure 4).  In the central area, there is a mixture of adipose tissue, fibrous trabeculae and numerous salivary gland acini.  Some dilated ducts are also seen (figure 5).  Other areas show acinar predominance and numerous ectatic ducts lined by flat cuboidal epithelium (figure 6).  Numerous dilated ducts are arranged in a lobular-like structure with prominent fibrosis (figure 7).


Focally, there is marked dilatation of ducts with prominent fibrosis of the wall infiltrated by nodular aggregates of lymphocytes, resembling small lymphoepithelial cysts (figure 8, figure 9)


What is your diagnosis? 


(scroll down to continue)





























Sialolipoma of the soft palate


Discussion (written by contributor)


Intraoral lipoma is a well-known entity (1, 2) but lipomatous tumors including salivary gland tissue containing clustered or peripherally located ducts in acinar glandular tissue are uncommon.  Under the designation of sialolipoma, Nagao et.  al. from Japan described a new variant of salivary gland lipomatous tumor (3).  They reported seven cases, five men and two women, aged 20-75 years old.  Five tumors were located in the parotid gland, one in the hard palate and one in the soft palate.


Grossly, the tumors were well circumscribed and resembled an ordinary lipoma.  Histologically, they were characterized by a proliferation of mature adipose tissue intermingled with acinar, ductal, basal and myoepithelial cells of normal salivary gland.  Duct ectasia with fibrosis and prominent lymphoid infiltrates with nodular aggregates in the stroma is a constant finding.


These tumors have benign behavior.  No recurrences have been noted, including from recent reports in the floor of the mouth (4) or the parotid gland (5).

This Case corresponds to the fourth reported case of sialolipoma located in the oral cavity and the second in the soft palate.




1.  Ellis Gl, Auclair Pl. Tumors of the salivary glands. Atlas of Tumor Pathology (Third series, Vol 17), Washington DC. Armed Forces Institute of Pathology 1996


2.  Hatziotis JC. Lipoma of the oral cavity. Oral Surg Oral Med Oral Pathol 1971;31:511


3.  Nagao T, et al: Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma.  Histopathology 2001;38:30


4.  Lin YJ, et al: Sialolipoma of the floor of the mouth: a case report. Kaohsiung J Med Sci 2004;20:410


5.  Michaelidis IG, et al: Sialolipoma of the parotid gland. J Craniomaxillofac Surg 2006;34:43



Nat Pernick, M.D.
PathologyOutlines.com, LLC
30100 Telegraph Road, Suite 404
Bingham Farms, Michigan (USA) 48025
Telephone: 248/646-0325
Fax: 248/646-1736
Email: NPernick@PathologyOutlines.com