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primary non - hodgkin lymphoma ( nhl ) of the breast is rare , representing 0.5% of all malignant breast tumors , 1% of all nhls and 2% of all extranodal lymphomas . as for the lymphoid lineage ,
b - cell lymphomas of the breast are more common than t - cell lymphomas .
currently , for diagnosing primary breast lymphomas ( pbls ) , the histologic criteria proposed by wiseman and liao ( 1972 ) are accepted as the  standard  for differentiating a pbl from the secondary form .
the close anatomic proximity of mammary and lymphomatous tissue , absence of a previous diagnosis of an extra - mammary lymphoma , lack of evidence of a disseminated disease ( except for the ipsilateral axillary nodal involvement ) and an adequate quality of the histopathological specimen are the four accepted criteria .
fine needle aspiration cytology ( fnac ) plays a significant role in the diagnosis of pbl and there have been a few case reports and rare series studies highlighting its importance in the diagnosis of pbl and its differentiation from the secondary lymphomatous involvement of the breast .
hence , fnac becomes an indispensible tool to diagnose pbl and thus avoid unnecessary surgery .
a 52-year - old woman presented with a painful left breast mass of 3 months duration and left axillary lymph node enlargement of 10 days duration .
the breast mass measuring 8 cm in its maximum dimension was mobile , tender and firm to hard in consistency . the overlying skin , nipple and areola were unremarkable .
no organomegaly or any other lymph node involvement ( except for the palpable ipsilateral axillary node ) was detected on ultrasonogram .
fna of the breast mass and the axillary lymph node was performed by the standard procedure .
aspirates from both the sites , revealing a similar cytomorphologic picture , were cellular with predominantly sheets and a few clusters of polymorphous population of lymphoid cells lacking typical reactive spectrum in a background displaying many lymphoglandular bodies .
the cells comprised predominantly large cells admixed with some intermediate - sized cells and small lymphocytes .
the large cells showed a scanty basophilic cytoplasm , round nuclei having a fine chromatin and small nucleoli ; some of the nuclei were cleaved .
highly cellular fine needle aspiration smear showing sheets of atypical lymphoid cells that are mainly large and intermediate sized with lymphoglandular bodies in the background ( arrows ) ( mgg , 400 ) an incisional biopsy was performed that showed a diffuse monotonous population of predominantly large lymphoid cells [ figure 2 ] .
on immunohistochemistry ( ihc ) , these cells showed a diffuse cytoplasmic positivity for cd20 and negative expression of cytokeratin .
section showing a diffuse , monotonous population of large lymphoid cells consistent with a lymphoma ( h and e , 400 )
a 52-year - old woman presented with a painful left breast mass of 3 months duration and left axillary lymph node enlargement of 10 days duration .
the breast mass measuring 8 cm in its maximum dimension was mobile , tender and firm to hard in consistency . the overlying skin , nipple and areola were unremarkable .
no organomegaly or any other lymph node involvement ( except for the palpable ipsilateral axillary node ) was detected on ultrasonogram .
fna of the breast mass and the axillary lymph node was performed by the standard procedure .
aspirates from both the sites , revealing a similar cytomorphologic picture , were cellular with predominantly sheets and a few clusters of polymorphous population of lymphoid cells lacking typical reactive spectrum in a background displaying many lymphoglandular bodies .
the cells comprised predominantly large cells admixed with some intermediate - sized cells and small lymphocytes .
the large cells showed a scanty basophilic cytoplasm , round nuclei having a fine chromatin and small nucleoli ; some of the nuclei were cleaved .
suspicious of nhl  [ figure 1 ] . highly cellular fine needle aspiration smear showing sheets of atypical lymphoid cells that are mainly large and intermediate sized with lymphoglandular bodies in the background ( arrows ) ( mgg , 400 )
an incisional biopsy was performed that showed a diffuse monotonous population of predominantly large lymphoid cells [ figure 2 ] .
on immunohistochemistry ( ihc ) , these cells showed a diffuse cytoplasmic positivity for cd20 and negative expression of cytokeratin .
section showing a diffuse , monotonous population of large lymphoid cells consistent with a lymphoma ( h and e , 400 )
the small amount of lymphoid tissue in the breast is attributed to the rarity of pbl compared with the other extranodal sites . according to the world health organization classification system for breast tumors , malignant lymphomas of the breast
are subdivided into diffuse large b cell lymphoma ( dlbcl ) , burkitt 's lymphoma , extranodal marginal zone b - cell lymphoma of mucosa - associated lymphoid tissue ( malt ) type and follicular lymphoma .
pbls are usually nhls of the b - cell lineage . the age incidence of pbl varies .
a painless mass is the most common presentation of pbl ( approximately 61% of cases ) .
other symptoms and signs include local pain ( 12% ) , local inflammation ( 11% ) and palpable lymph nodes ( 25% ) . almost always , the breast lymphomas are diagnosed by an excisional biopsy or fnac . our case of pbl
was diagnosed by fnac on excluding an extranodal spread of lymphoma elsewhere to the breast by a detailed clinico - radiologic examination .
the presence of lymphoglandular bodies in the smear background is a useful indicator of the lymphoid nature of the cells .
thus , despite the uncommon occurrence of breast lymphomas , their presence along with atypical lymphoid cells suggested a possibility of nhl . considering the breast location of the lesion , ihc with pan - cytokeratin ( pan - ck ) was performed to exclude breast carcinoma , which was negative .
however , aspiration cytology in such cases shows a mixed population of lymphocytes , indicative of a reactive process . in the present case , despite the mixed population of cells , the lack of a classic reactive spectrum suggested a possibility of nhl and the monoclonal b cell population on ihc confirmed the diagnosis of nhl .
the chloromas are recognized by the presence of mature myeloid cells , which were absent in our case .
further , the blood counts , peripheral blood smear and ihc findings were also not indicative of a chloroma .
however , similar to the nodal / gastrointestinal lymphomas , a diagnostic biopsy or a limited surgery followed by chemotherapy accompanied by radiotherapy is recommended .
one of the recent studies emphasized the importance of differentiating pbl from breast carcinoma , which is important for avoiding unnecessary mastectomy in pbl .
although there was a clinical suspicion of breast carcinoma , an appropriate pre - therapeutic clinical workup with an fna suspicion of nhl and ihc confirmation on the needle biopsy specimen avoided an unnecessary mastectomy in our patient .
attention to features such as atypical lymphoid cells lacking reactive spectrum and the presence of lymphoglandular bodies served as
primary non - hodgkin lymphoma of breast is a rare pathology , representing 0.5% of malignant breast tumors . 
 we report a case of 52 year old female presenting with a large painful mass in left breast with ipsilateral axillary lymph node diagnosed on fine needle aspiration cytology as non - hodgkin 's lymphoma . 
 breast lymphoma should be differentiated from other breast malignancies because of the differences in their treatment modalities . 
 when breast lymphoma presents as a lump with axillary node , it clinically mimics breast carcinoma . 
 ultrasonogram and mammogram shows no characteristic features that can distinguish it from other breast malignancy . in such cases 
 , fnac becomes an important diagnostic tool that can differentiate pbl from other breast malignancy and avoid unnecessary surgery .