these are non - neoplastic , tumor - like lesions of unknown etiology and are composed predominantly of polyclonal plasma cells . in 1968 , bhaskar , levin and firch first reported the cases of gingival plasma cell granuloma . although plasma cell granuloma ( pcg ) occurs most commonly in lungs , other organs may be involved . in head and neck , the areas most commonly involved are the orbit and paranasal sinuses , but they have been also described in the larynx , pterygomaxillary space , tonsils , ears , tongue , lip , oral mucosa , periodontal tissues and rarely gingiva . literature reviewed shows that gingival plasma cell granuloma is exceedingly rare and very few case reports of gingival plasma cell granuloma have been observed . intraoral pcg occurs in a wide age range of 19 months to 63 years , but most of the cases of gingival pcg are observed in 4 and 5 decades of life and there is a slight female predominance . radiologically some oral lesions have shown infiltrative margins giving an appearance of a malignant tumor . hence such lesions should be histologically examined to decide the exact nature of these lesions . a 58-year - old woman was admitted in november 2010 who presented with an enlarging , painless mass in the oral cavity . the mass was polypoidal , nontender , firm measuring 3  2 cms and was located on the inner aspect of upper gingiva extending from right middle incisor to the left canine region . grossly , the lesion was polypoidal and solid measuring 3  2  1.5 cms with smooth white cut surface [ figure 1 ] . the mass was composed of nodular infiltrates of mature plasma cells admixed with lymphocytes and histiocytes on the background of loose myxoid and collagenized stroma showing scattered fibroblasts and myofibroblasts [ figures 2 and 3 ] . in areas , immunostaining for kappa and lambda light chains revealed a polyclonal plasma cell population [ figures 5 and 6 ] . gross photograph showing polypoidal mass with smooth white cut surface histological picture showing spindle cell proliferation admixed with dense lymphoplasmacytic infiltrate ( h and e 100 ) histological picture showing fibroblasts and myofibroblasts ( h and e 400 ) histological picture showing predominance of plasma cell along with russell bodies . inset shows russell body ( h and e 400 ) immunohistochemistry for kappa chains immunohistochemistry for lambda chains grossly , the lesion was polypoidal and solid measuring 3  2  1.5 cms with smooth white cut surface [ figure 1 ] . the mass was composed of nodular infiltrates of mature plasma cells admixed with lymphocytes and histiocytes on the background of loose myxoid and collagenized stroma showing scattered fibroblasts and myofibroblasts [ figures 2 and 3 ] . in areas , immunostaining for kappa and lambda light chains revealed a polyclonal plasma cell population [ figures 5 and 6 ] . gross photograph showing polypoidal mass with smooth white cut surface histological picture showing spindle cell proliferation admixed with dense lymphoplasmacytic infiltrate ( h and e 100 ) histological picture showing fibroblasts and myofibroblasts ( h and e 400 ) histological picture showing predominance of plasma cell along with russell bodies . inset shows russell body ( h and e 400 ) immunohistochemistry for kappa chains immunohistochemistry for lambda chains plasma cell granuloma is a rare tumor like lesion characterised histologically by fascicles of spindle mesenchymal cells admixed with chronic inflammatory cells predominantly plasma cells . it has various components like fibroblasts , myofibroblasts , inflammatory cells ( plasma cells , lymphocytes , histiocytes , mast cells and eosinophils ) . all these components are arranged in varying proportions and thus create a marked histological diversity . depending upon the predominant components , it has various nomenclatures like plasma cell granuloma , plasma cell pseudotumor , inflammatory pseudotumor , inflammatory myofibroblastic tumor , and myofibrohistiocytic proliferation . the histologic diversity has led to conflicting opinions regarding the inflammatory or neoplastic nature of this lesion . the finding of human herpesvirus-8 dna sequences and over expression of human interleukin 6 and cyclin d1 has been recently reported in seven cases . kim et al . suggested that interleukin-6 ( il-6 ) and phospholipase c-1 may induce heavy plasma cell infiltration in cyclosporine - induced gingival overgrowth . debate exists about the inflammatory or neoplastic nature of this lesion , with majority of reports siding with the post inflammatory reactive process . some cases show a predominance of mature plasma cells and lymphocytes that are mixed with histiocytes and only a minor mesenchymal component . other cases are composed predominantly of bland fibroblasts and myofibroblast spindle cells arranged in interlacing fascicles or storiform pattern with only a minor component of inflammatory cells . the spindle cells stain positive with antibodies to vimentin and actin , and rarely , occasional cells stain with desmin , which is consistent with fibroblasts and myofibroblasts . however spindle cells of some lesions have been shown to possess a persistent abnormality involving chromosome 2p23 a alk gene locus , which is consistent with a neoplastic nature of this lesion . pcg / ipt may be misinterpreted by the pathologists as nodular fasciitis , fibromatosis , fibrosarcoma or plasmacytoma . nodular fasciitis rarely occurs in the oral cavity and it is characterised histologically by the presence of loose myxoid matrix containing short linear curved fascicles of spindle cells . fibromatosis of the oral cavity usually occurs in young adults and it is characterised histologically by broad interlacing fascicles of mature fibroblasts with a variable degree of collagenisation . an inflammatory component is absent . oral pcg needs to be distinguished from the recently described follicular dendritic cell tumor of the oral cavity , which runs an indolent course with a tendency of local recurrence . it can closely mimic inflammatory pseudotumor with whorls or fascicles of plump spindle cells in an inflammatory background of lymphocytes and histiocytes . in contrast , plasma cells constitute a significant proportion of the chronic inflammatory cells in inflammatory pseudotumor . the distinction can be established by the positive staining for cd21 , ber - mac - drc , and ki - m4 in follicular dendritic cell tumor . in view of predominance of plasma cells in our case the differential diagnosis considered was plasmacytoma . in plasmacytoma , there are diffuse sheets of neoplastic , variably differentiated , monoclonal plasma cells . mitotic activity and amyloid deposition may be present and the inflammatory cells are very sparse . the other polyclonal lesions of gingiva include plasma cell gingivitis , which is usually not a localised nodular lesion but presents as generalised oedematous and erythematous elevations . naderi et al . in their study of 2068 cases of reactive lesions of oral cavity found that peripheral giant cell granuloma was the most prevalent lesion of gingiva . bhaskar , levin and firch reported 45 cases of pcg of periodontal tissue and this appears to be the first report on this pathologic entity on the gingival tissue . acevedo and buhler , earl and lowry , ide and shimoyama , peacock me , shin jm , karthikeyan and pradeep , baltaciaglu , namboodiripad , phadnaik , balaji manohar and s bhuvaneshwari , have described single case reports of pcg of the gingiva . their clinical presentation and histopathological findings are similar to those observed in the present case . kim ss and eom d have described two cases of pcg in cyclosporine induced gingival overgrowth . in january 2011 kim ys , lee sk described 14 cases of pcg out of 59 chronic inflammatory gingival lesions examined . plasma cell predominant type ( ppt ) , mixed inflammatory cell type ( mict ) , and sclerosed fibrosis type ( sft ) . the results of immunohistochemical studies on these cases suggest that a gingival plasma cell granuloma shows variable gene expression for cell - mediated immunity and stromal tissue degeneration , undergoing sclerotic fibrosis with a persistent inflammatory reaction . states that pure pcg should not be called as inflammatory pseudotumor and the term imt should be applied only for genuine lesions of myofibroblasts . pcg in the oral cavity is usually benign and simple excision of the lesion is curative . in our case after that the patient was lost for follow up . although surgery is the principal treatment , regression and response to corticosteroids and nonsteroidal inflammatory agents have been noted in rare cases plasma cell granuloma of the gingiva is a rare entity that may be confused with a malignant tumor on clinical and radiographic grounds . the gross and microscopic similarities to other oral spindle cell tumors can also be misinterpreted as those of a more aggressive lesion . so awareness of oral pcg / inflammatory pseudotumor and its distinctive morphologic features is important in avoiding the misdiagnosis . it is also important to recognize this entity as a benign inflammatory lesion to avoid unnecessarily extensive and potentially destructive surgery .
plasma cell granuloma , also known as inflammatory pseudotumor is a tumor - like lesion that manifests primarily in the lungs . 
 but it may occur in various other anatomic locations like orbit , head and neck , liver and rarely in the oral cavity . 
 we here report an exceedingly rare case of gingival plasma cell granuloma in a 58 year old woman who presented with upper gingival polypoidal growth . 
 the histopathological examination revealed a mass composed of proliferation of benign spindle mesenchymal cells in a loose myxoid and fibrocollagenous stroma along with dense infiltrate of chronic inflammatory cells predominantly containing plasma cells . 
 immunohistochemistry for kappa and lambda light chains showed a polyclonal staining pattern confirming a diagnosis of plasma cell granuloma .