IJCRI – International Journal of Case Reports and Images, Vol. 3 No. 5, May 201 2. ISSN – [0976-31 98]

IJCRI 201 2;3(5):21 –24.www.ijcasereportsandimages.com

Primary extranodal marginal zone B­cell lymphoma ofhard palate: A case reportArpan K Shah, Mahesh H Gabhane, Meena M Kulkarni

ABSTRACTIntroduction: MALT (mucosa associatedlymphoid tissue) lymphomas comprise aheterogeneous group, originally thought to bederived from the marginal zone B­cells that arefound surrounding B­cell follicles and within theadjacent lymphoepithelium. They arise mostcommonly in extranodal organs such as thestomach, major salivary glands and thyroid.Thus, they can be precisely described asextranodal marginal zone B­cell lymphomas(ENMZL). Here, we report a case of MALTlymphoma arising in the palatal minor salivaryglands. Case Report: A 55­year­old womanpresented with two years history of a leftposterior palatal mass. Clinical investigations ofthe case included computed tomography (CT)scan for the assessment of bone destruction andpossible intra­maxillary extension.Histopathological features andimmunohistochemistry findings were consistentwith the diagnosis of extranodal marginal zone

B­cell lymphoma of MALT type. The lesion wastreated by complete surgical excision andfollowed for two years. Conclusion: Even thoughoral localization of ENMZL is rare, it should beincluded in the differential diagnosis of benign­appearing swellings of oral cavity.Keywords: Extranodal, Histopathology,Lymphoma, MALT, Palate

*********Shah AK, Gabhane MH, Kulkarni MM. Primaryextranodal marginal zone B­cell lymphoma of hardpalate: A case report. International Journal of CaseReports and Images 2012;3(5):21–24.

*********doi:10.5348/ijcri­2012­05­119­CR­4

INTRODUCTIONMalignant lymphomas of the oral cavity areuncommon and account for 3.5% of all oralmalignancies [1]. Lymphomas arising from the mucosaassociated lymphoid tissue (MALT) were originallydescribed by Isaacson and Wright in the gastrointestinaltract. They specified them as B­cell lymphomas [2].MALT lymphomas account for a significant proportionof extranodal lymphomas. In the head and neck regionexcept for the salivary glands the occurrence of theselymphomas is very rare, hence very few cases of primaryintraoral MALT lymphoma have been reported so far [3,4]. In the present paper, we report a case of 55­year­oldfemale with soft tissue swelling involving posterior hardpalate. Clinio­radiological profile was suggestive of achronic inflammatory lesion or a benign neoplasm ofpalatal minor salivary glands. Microscopic examination

CASE REPORT OPEN ACCESS

Arpan K Shah1 , Mahesh H Gabhane2, Meena M Kulkarni3

Affi l iations: 1Senior lecturer, Department of oral Pathology& Microbiology, MP Dental College & Hospital, Vadodara,Gujarat, India; 2Senior lecturer, Department of oralPathology & Microbiology, SMBT Dental College &Hospital, Sangamner, Maharashtra, India; 3Professor &Head, Department of Oral Pathology & Microbiology,Rural Dental College & Hospital, Loni, Maharashtra,India.Corresponding Author: Arpan K Shah, A-48/ NilkanthPark, Tilakwada bypass road, Dabhoi, Gujarat, India -39111 0; Ph: +91 9898932532; Email :drarpan_shah@rediffmail .com

Received: 02 September 2011Accepted: 1 9 November 2011Published: 31 May 201 2

Shah et al. 21

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IJCRI 201 2;3(5):21 –24.www.ijcasereportsandimages.com Shah et al. 22

of the lesion was consistent with extranodal marginalzone B­cell lymphoma of MALT type. Clinical work­up,histopathology, immunohistochemical findings,treatment details and follow­up of the case arediscussed here.

CASE REPORTA 55­year­old female presented with a swelling inposterior palatal region since two years. Intraoralexamination revealed a swelling involving posteriorhard palate on left side, which was soft in consistency(Figure 1). Computed tomography (CT) scan confirmedan oval soft tissue density lesion (19×14 mm) along theleft posterolateral aspect of hard palate, partlyextending along the soft palate with no evidence ofintra­maxillary extension of the lesion (Figure 2).Diagnostic incisional biopsy of the lesion revealed it asbenign lymphoid hyperplasia.After complete surgical excision, microscopicexamination of the lesion showed diffuse infiltration ofmonomorphic small round cells within the connectivetissue. Sheets of lymphoid cells were separated from theoverlying epithelium by a well­defined band offibrovascular tissue (Figure 3). Some lymphoid follicleswith follicle center and mantle zone were seen. Manyminor salivary gland acini and ducts were observed,some of which showed infiltration by lymphoid cells,forming the lymphoepithelial lesions (Figure 4). Onhigher magnification, the round cells were centrocyte­like, with scant cytoplasm and nuclei containingclumped chromatin. Some plasma cells were also noted.In addition to routine hematoxylin and eosin staining, apanel of immunohistochemical markers was used toarrive at final diagnosis. Leukocyte common antigen(LCA) was used to confirm the neoplasm was indeedcomposed of lymphocytes. Monoclonal intracytoplasmicimmunoglobulin was detected byimmunohistochemistry, which confirmed neoplasticorigin of the B­cells (Figure 5). The tumor cells werePanCK­, CD5­, CD3­, CD10­, CD20+, and CD23­.Immunohistochemistry for additional markers was notperformed because the aforementionedhistopathological findings were considered diagnosticfor MALT lymphoma. Because fresh tissue was notavailable for study, flow cytometry and cytogeneticanalysis was not performed. Peripheral bloodexamination and protein electrophoresis were withinnormal limits. A bone marrow biopsy was negative forthe presence of neoplastic cells.The present case is consistent with the diagnosis oflow­grade MALT lymphoma. The patient haduneventful postoperative course.

DISCUSSIONAbout 20% of oral non­Hodgkin’s lymphomas arisein palatal soft tissues [5]. Extranodal marginal zonelymphomas (ENMZL) constitute a heterogeneous group

showing neoplastic cells resembling normal marginalzone B cells [5]. These lymphomas are characterized bytheir mucosal and glandular tissue localization andcommonly referred to as mucosa­associated lymphoidtissue (MALT) lymphomas [6].ENMZL have peculiar clinicopathological profile thatset them apart from other lymphomas. They tend toremain localized for prolonged intervals and the lesionis commonly confused with an inflammatory process (asevident in the present case). However, the presence ofmonoclonality in these lesions correlates with risk ofdissemination and therefore supports their designationas lymphoma [7].Etiopathogenesis of MALT lymphoma is poorlyunderstood. Chronic inflammatory conditions such aschronic sinusitis, Sjogren’s syndrome, benignlymphoepithelial lesion or myoepithelial sialadenitis(MESA) have been suggested as precursors for the

Figure 1: Swelling involving left posterolateral aspect of hardpalate.

Figure 2: Computed tomography scan showing soft­tissueradiodensity in left posterolateral area of hard palate.

IJCRI – International Journal of Case Reports and Images, Vol. 3 No. 5, May 201 2. ISSN – [0976-31 98]

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Figure 3: Palatal connective tissue diffusely infiltrated withmonomorphic lymphoid cells. (H&E stain, x100).

development of MALT lymphoma in this location [3, 7].The indolent nature of the disease in these cases ismanifested by persistence of the lesion without overtclinical evidence of distant spread even after 14 months[8]. Persistence of the lesion for duration of 24 monthsin present case is suggestive of MALT lymphoma.Histopathological distinction between a reactivelymphoid infiltrate and MALT­lymphoma can bedifficult. According to Vega et al., larger the lymphoidinfiltrate, greater the likelihood of lymphoma [7].Monomorphous lymphoid population exhibitingcentrocyte­like or monocytoid morphology, formingwide zones surrounding epimyoepithelial islands is auseful histological finding suggestive of MALTlymphoma [7]. Kojima et al. described two distincthistopathological patterns of primary oral MALTlymphoma. The first pattern is characterized byoccasional follicular colonization and the presence oflymphoepithelial lesions. Another pattern shows a

Figure 4: Centrocyte­like cells invading epithelial structureforming lymphoepithelial lesion (H&E stain, x400).

prominent follicular colonization resembling the “floralvariant” of follicular lymphoma [4]. Present caseshowed histological features described in the formerpattern.In contrast to the relatively poor outcome of other B­cell lymphomas, MALT lymphomas have a betterprognosis making them amenable to complete surgicalremoval [3]. Survival in the present case, two years afterdiagnosis, is consistent with this finding.

CONCLUSIONRarity of occurrence of MALT lymphoma in oralcavity, clinical profile resembling benign process,peculiar histopathology and varied

Figure 5: Expression of monotypic immunoglobulin patternsuggesting monoclonal origin of tumor cells.(Immunohistochemical stain, kappa, x400).

Figure 6: Positive immunoexpression of pancytokeratin inepithelial cells and negative staining of lymphocytes in thelymphoepithelial island. (Immunohistochemical stain,pancytokeratin, x400).

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immunohistochemistry findings make such casesinteresting to study. Considering their low­grademalignant behavior and indolent clinical course,ENMZL should be included in the differential diagnosisof benign appearing swelling of oral cavity*********

AcknowledgementsAuthors are thankful to Dr. Madnoorkar (MS, DNB),Consulting Oncosurgeon, and Dr. Sushil Ahire (MD),Consulting Pathologist, NAMCO charitable trust’scancer hospital, Nashik, India, for their contribution.Author ContributionsArpan K Shah – Conception and design, Acquisition ofdata, Analysis and interpretation of data, Drafting thearticle, Critical revision of the article, Final approval ofthe version to be publishedMahesh H Gabhane – Conception and design,Acquisition of data, Analysis and interpretation of data,Drafting the article, Critical revision of the article, Finalapproval of the version to be publishedMeena M Kulkarni – Conception and design,Acquisition of data, Analysis and interpretation of data,Drafting the article, Critical revision of the article, Finalapproval of the version to be publishedGuarantorThe corresponding author is the guarantor ofsubmission.Conflict of InterestAuthors declare no conflict of interest.Copyright© Arpan K Shah et al. 2012; This article is distributedunder the terms of Creative Commons attribution 3.0License which permits unrestricted use, distribution andreproduction in any means provided the original authorsand original publisher are properly credited. (Please seewww.ijcasereportsandimages.com /copyright­policy.phpfor more information.)

REFERENCES1. Epstein JB, Epstein JD, Le ND, Gorsky M.Characterization of oral and paraoral malignantlymphoma: A population­based review of 361 cases.Oral Surg Oral Med Oral Pathol Oral Radiol Endod2001;92:519–25.2. Isaacson PG, Wright DH. Malignant lymphoma ofmucosa­associated lymphoid tissue. A distinctivetype of B­cell lymphoma. Cancer 1983;52:1410–6.3. Tauber S, Nerlich A, Lang S. MALT lymphoma of theparanasal sinuses and the hard palate: report of twocases and review of literature; Eur Arch Otolaryngol2006;263:19–22.4. Kojima et al; Histopathological variation of primaryMucosa­associated lymphoid tissue lymphoma of theoral cavity. Pathol Oncol Res 2007;13(4):345–9.

5. Kemp S, Gallagher G, Kabani S, Noonan V, Hara C;Oral non­Hodgkin’s lymphoma: review of theliterature and World Health Organizationclassification with reference to 40 cases. Oral SurgOral Med Oral Pathol Oral Radiol Endod2008;105:194–1.6. Margiotta V et all; Gastric and Gingival localizationof Mucosa­associated lymphoid tissue (MALT)lymphoma. An Immunohistochemical, virologicaland clinical case report. J Periodontol1999;70:914–8.7. Vega F, Lin P, Medeiros J. Extraoral lymphomas ofthe head and neck. Ann Diag Pathol;2005:9:340–50.8. Ihrler S, Harrison JD. Mikulicz’s disease andMikulicz’s syndrome: Analysis of the original casereport of 1892 in the light of current knowledgeidentifies a MALT lymphoma. Oral Surg Oral MedOral Pathol Oral Radiol Endod 2005;100:334–9.