|Year : 2012 | Volume
| Issue : 4 | Page : 641-643
Primary malignant lymphoma of the parotid gland
Sudha H Metikurke1, Rashmi Krishnappa1, Sreevathsa M Ramachar2, Iteeka Arora1
1 Department of Pathology, M S Ramaiah Medical College and Teaching Hospital, Bangalore, India
2 Department of General Surgery, M S Ramaiah Medical College and Teaching Hospital, Bangalore, India
|Date of Web Publication||29-Jan-2013|
House No 861, 1st Floor, Kengeri Main Road, Kengeri Satellite Town, Bangalore - 560060
Source of Support: None, Conflict of Interest: None
Lymphoma of the salivary gland accounts for 5% of cases of extranodal lymphoma and 10% of malignant salivary gland tumors. Most primary salivary gland lymphomas are B marginal zone lymphomas arising on a background of sialadenitis associated with an autoimmune disorder such as Sjorgen's syndrome. This report describes a case of primary B-cell lymphoma arising in the parotid gland in a middle-aged female, which was not associated with an autoimmune disorder. Immunohistochemistry studies confirmed the clonal B-cell nature of the tumor. This case highlights the fact that B-cell lymphoma in the salivary gland can go unrecognized due to its non-specific symptoms and requires immunohistochemistry studies for confirmation. We present this case for its rarity.
Keywords: Histopathology, immunohistochemistry, non-Hodgkin lymphoma, parotid salivary gland
|How to cite this article:|
Metikurke SH, Krishnappa R, Ramachar SM, Arora I. Primary malignant lymphoma of the parotid gland. J Can Res Ther 2012;8:641-3
| > Introduction|| |
Non-Hodgkin lymphoma accounts for approximately 25% of head and neck lymphomas. Most common sites are pharynx, paranasal sinuses, nasal cavity, oral cavity, thyroid, orbit, central nervous system and salivary glands. Primary malignant lymphomas of the salivary gland are uncommon, accounting for 1.7-3.1% of all salivary gland neoplasms and 0.6-5% of all tumor and tumor-like lesions of the parotid gland.  Although the parotid gland is the most common site of origin, submandibular, minor salivary gland and sublingual glands can be involved rarely by non-Hodgkin's lymphoma. Within the parotid gland malignant lymphoma is often clinically unsuspected, often presenting as non-specific masses, thus indistinguishable from other more common epithelial tumors.
| > Case Report|| |
A 45-year-old female presented with history of slow-growing swelling over the left side of the face since two years. On examination there was no associated lymphadenopathy or hepatosplenomegaly.
Thus clinically, a provisional diagnosis of pleomorphic adenoma of the left parotid was made. Fine needle aspiration cytology of the same was reported as reactive hyperplasia. Left superficial parotidectomy was done and the specimen was sent to the department of pathology for histopathological examination.
Gross: Received four irregular, grey brown, lobulated soft tissue masses, largest measuring 3 × 2.2 × 0.5 cm and smallest measuring 1.5 × 1 × 0.3 cm. The cut surface of the masses showed ill-defined grey white to grey brown lesion measuring 2.9 × 2.2 × 0.5 cm surrounded by a thin rim of normal salivary gland tissue [Figure 1]. Representative bits were taken and stained by hematoxylin and eosin.
|Figure 1: Gross: Grey white infi ltrative tumor surrounded by a rim of normal parotid gland|
Click here to view
Microscopy: Showed salivary gland parenchyma with infiltrating malignant neoplasm [Figure 2] extending focally up to the circumferential margin. The tumor cells were arranged in diffuse sheets. They were small round to oval lymphoid cells with hyperchromatic nucleus and scanty amount of cytoplasm [Figure 3]. Epi-myoepithelial islands were seen interspersed amidst lymphoid component [Figure 4].
|Figure 2: Microscopy shows parotid gland with adjacent infi ltrating neoplasm (40X, H&E)|
Click here to view
|Figure 3: Diffuse sheets of neoplastic small round lymphocytes (160X, H&E)|
Click here to view
|Figure 4: Neoplastic lymphocytes infi ltrating parotid gland (160X, H&E)|
Click here to view
Impression: Non-Hodgkin lymphoma - diffuse small-cell type was offered and immunohistochemistry was advised for confirmation. Immunohistochemistry confirmed extranodal marginal zone lymphoma of left parotid gland with focal transformation to diffuse large B-cell lymphoma with positivity for CD20, focal positivity for CD10 and negative for CD3, CD5, CD68, MPO, cyclinD1 and Tdt.
| > Discussion|| |
Non-Hodgkin lymphoma of the parotid gland usually presents as a painless, progressive enlarging mass. Primary salivary gland lymphoma is rarely suspected before biopsy because only about 5% of all salivary gland tumors are malignant lymphomas. ,
Primary salivary gland lymphoma is defined as enlargement of parotid gland at first presentation, followed by pathological diagnosis that includes parenchymal involvement of the salivary gland without evidence of lymph node origin. ,
The majority of salivary gland lymphomas are non-Hodgkin lymphomas of B-cell type, especially MALT (Mucosa Associated Lymphoid Tissue) lymphomas. MALT lymphoma is associated with chronic inflammatory process in response to either an infection or immune process such as Sjogren's syndrome and myoepithelial sialadenitis. 
Schusterman et al., noticed a progressive increase in the incidence of salivary gland lymphomas during the last several decades. This may result from a combination of factors: (1) referral pattern, (2) increased lifespan of individual and (3) use of sophisticated molecular techniques. ,,
Malignant lymphomas of the parotid gland are uncommon in patients younger than 50 years with 2:1 male to female ratio. The impact of histological grade, stage of the disease and presence or absence of an underlying autoimmune disease on clinical outcome is controversial. ,
In summary, primary malignant lymphomas of the parotid gland are uncommon. Clinically they manifest as a unilateral, slow-growing painless mass. Most are of these tumors are B-cell type of non-Hodgkin lymphoma.
| > Acknowledgement|| |
We are thankful to Dr. Mahadeva K C, Professor and HOD and Dr. Vijaya Mysorekar, Professor, Department of Pathology for their support.
| > References|| |
|1.||Cho G, Suh IS, Tak KS, Park YK, Ko EY, Sung HM, et al. Primary Parotid Non-Hodgkin's lymphoma: Case report. J Korean Cleft Palate- Craniofac Assoc 2010;11:99-102. |
|2.||Roh JL, Huh J, Suh C. Primary Non Hodgkin's Lymphoma of the major salivary glands. J Surg Oncol 2008;97:35-9. |
|3.||Gleson MJ, Bennet MH, Cawson RA. Lymphoma of salivary gland. Cancer 1986;58:699-704. |
|4.||Dunn P. Kuo TT, Shih LY, Lin LT, Wang PN, Kuo MC, et al. Primary salivary gland lymphoma: Clinico-pathologic study of 23 cases in Taiwan. Acta Haematol 2004;112:203-8. |
|5.||Hyman GA, Wolff M. Malignant lymphoma of the salivary gland. Review of literature and report of 33 new cases, including four cases associated with lymphoepithelial lesion. Am J Cin Pathol 1976;65:421-8. |
|6.||Schmid U, Helboon D, Lennert K. Development of malignant lymphoma in myoepithelial sialadenitis (Sjogren's syndrome). Virchows Arch A Pathol Anat Histol 1982;395:11-43. |
|7.||Barnes L, Myers EN, Prokopakis EP. Primary malignant lymphoma of parotid gland. Arch Otolaryngol Head Neck Surg 1998;124:573-7. |
|8.||Schusterman MA, Granick MS, Erickson ER, Newton ED, Hanna DC, Bragdon RW. Lymphomas presenting as a salivary gland mass. Head Neck Surg 1988;10:411-5. |
|9.||Scubba JJ, Acular PL, Ellis Gl. Surgical pathology of salivary gland. Philadelphia: WB Saunders Company; 1991. p. 528-33. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]