salivary gland neoplasms constitute an important area in the field of pathology of head and neck region . they are mainly classified as either hodgkin 's or non - hodgkin 's lymphoma ( nhl ) . nhl comprises a heterogeneous group of lymphoid neoplasms with a spectrum of behaviour ranging from relatively indolent to highly aggressive and potentially fatal . the vast majority of nhl represent b cell and less commonly t cell lineage neoplasm . nhls of b cell origin are known to be relatively common in extra nodal sites and many are thought to originate from mucosa associated lymphoid tissue ( malt ) . this is a low to intermediate grade lymphoma that show a follicular architecture and represents the neoplastic counterpart of germinal center b lymphocytes . follicular lymphoma is very uncommon under the age - group of 40 years and is extremely rare in children . the t ( 14;18 ) ( q32;q21 ) chromosome translocation has been purported to be the cytogenetic hallmark of follicular lymphoma . the molecular consequence is deregulation of bcl2 expression leading to over expression of bcl2 proteins in neoplastic follicles . a 40-year - old female patient reported to our institute with a complaint of swelling in the left side of lower jaw since 2 months [ figure 1 ] . post its onset , the swelling gradually increased in size over a period of 2 months . the patient is a known diabetic since 5 years and is under oral anti diabetic medication . concurrent with the history of swelling , the patient gives a history of weight loss in past 2 months . no history of cold , cough or fever . clinical picture showing the swelling in the left submandibular region examination revealed a swelling of 9  4 cm in size which extended anteriorly 1 cm in close proximity to chin on left side and posteriorly in line with the ear lobe [ figure 2 ] . margins were well - defined and the swelling was firm , fixed to underlying tissues and non tender on palpation . no local rise of temperature was seen in the concerned area . left submandibular lymph node was 0.5 cm in size and mildly tender on palpation . few differential diagnoses such as sarcoidosis , sjogren 's syndrome , lymphomas and mikulicz disease were considered . sjogren 's syndrome was ruled out as there was no history of dryness . in both sarcoidosis and sjogren 's syndrome mikulicz disease is an autoimmune disease and thus was ruled out . swelling seen 2 cm below the ear lobe the following investigations were done : 
 fnac gave an impression of chronic non specific lymphadenitis . no evidence of cytological atypia seenultra sonography report showed a circumscribed mixed area of 3  1.5 cm in the anterior region of left submandibular gland . no evidence of cytological atypia seen ultra sonography report showed a circumscribed mixed area of 3  1.5 cm in the anterior region of left submandibular gland . the patient was further subjected to ct scan of head and neck and the impression was of 
 submandibular salivary gland tumourmultiple submental and submandibular lymphadenopthy . , a diagnosis of benign tumour of the left submandibular gland was given . during excision of the tumour , it was found that whole of the gland was involved . so , total submandibular gland excision was done and the specimen was sent for histopathological analysis . gross finding revealed a single bit of soft tissue measuring 4  6 2 cm , yellowish red in color , firm in consistency . [ figure 3 ] cut sections revealed yellowish to whitish central core surrounded by whitish brown to brownish areas [ figure 4 ] . specimen showing 2 lymph nodes attached to the soft tissue specimen grossed specimen showing yellowish to whitish central core surrounded by whitish brown to brownish areas histopathological examination revealed hematoxylin and eosin ( h and e ) stained sections revealed destruction of salivary gland architecture . photomicrograph showing neoplastic lymphocytes in a follicular pattern.(h&e stain , 100 ) photomicrograph showing neoplastic lymphocytes with hyperchromatic nuclei and scanty cytoplasm . ( h&e stain , 200 ) based on the histopathological appearances , a provisional diagnosis of low grade lymphoma was made and immunohistochemical profiling was done to confirm the type of lymphoma . the tissue was stained for bcl2 an anti apoptotic marker , cd20 b lymphocyte marker , cd3 which is exclusively a t lymphocyte marker , cytokeratins and ema . immunohistochemistry revealed that the cells were strongly positive for bcl-2 [ figure 7 ] and cd 20 [ figure 8 ] which are both cytoplasmic markers and negative for cd3 [ figure 9 ] . ( ihc stain , 200 ) photomicrograph showing neoplastic cells expressing strong positivity for cd20 . ( ihc stain , 100 ) photomicrograph showing neoplastic cells with negative expression for cd3 . ( ihc stain , 100 ) based on the results of immunohistochemical profiling , a diagnosis of follicular b cell lymphoma was reached . patient was referred to higher center where full body mri did not reveal any foci of disease . nevertheless , considering the indolent course of this disease , she has been on regular follow up and has not reported with any clinically suspicious changes . lymphomas also involve in the descending order of frequency , the submandibular gland ( 30% ) , minor salivary glands and the sub lingual glands . the finding of a lymphoma in a major salivary gland could mean one of two things : either it is part of a disseminated process , or it is the first clinicopathologic evidence of lymphoma . in the latter instance , whether the disease originated in the glandular stroma itself or in a para glandular lymph node and then invaded the stroma , the lymphoma is defined as primary , as long as there is no detectable disease outside the salivary gland . hyman and wolf have given few criterions for diagnosis of primary lymphoma which are : 
 involvement of gland should be the first clinical manifestation of the diseasehistologically , the disease should involve the gland parenchyma and not the adjacent node or soft tissue alonethere should be confirmation of malignant nature of lymphoid infiltrate . involvement of gland should be the first clinical manifestation of the disease histologically , the disease should involve the gland parenchyma and not the adjacent node or soft tissue alone there should be confirmation of malignant nature of lymphoid infiltrate . lichenfield et al . , reserved the diagnosis of primary salivary gland lymphoma , when lymphoma has been ruled out elsewhere in the body . the diagnosis of lymphoma in case of a salivary gland swelling is rarely done preoperatively . even though the diagnosis of lymphomas , in the algorithm of diagnosis of salivary gland swelling is rare , nevertheless , it should be considered . follicular lymphoma , although unpredictable and often associated with a prolonged course shows indolent behavior . overtime , there is a tendency to transform to a higher grade of lymphoma , usually diffuse large cell lymphoma . although various treatment modalities exist , none are curative and very few have been shown to prolong survival .
lymphomas are neoplastic diseases of lymph nodes . 
 lymphoma of the salivary gland is rare accounting for less than 5% of lymphomas overall . 
 furthermore , lymphomas arising in the submandibular gland are reported to comprise 916% of all salivary gland lymphomas . among lymphomas originating from salivary glands , 
 the ratio of follicular lymphoma is very low . 
 they can also be seen in the lymph nodes of the salivary glands which is an uncommon presentation . here , 
 we present a case follicular lymphoma which presented as a salivary gland tumour .