fibrosarcoma of the breast is included in this group of sarcomas and this tumor is always malignant , although the malignancy may vary in degree . primary breast fibrosarcoma is a rare neoplasm . in a review of the literature , barnes and pietruszka   reviewed all the cases of breast sarcoma that were seen at the health center hospitals of the university of pittsburgh during the 1945 - 1976 period , and they found that only 10 cases of primary breast sarcoma had been reported . further , adem et al .   reported that primary breast sarcoma comprised only 0.0006% of all breast malignancies presenting at his institution from 1940 to 1999 . however , the exact incidence of primary breast fibrosarcoma is not known nor has it been reported in the literature . reports in the medical literature with the radiologic imaging of primary breast fibrosarcomas are also very rare . to the best of our knowledge , there has been no prior report of the sonographic imaging of primary fibrosarcoma of the breast in the english medical literature . here we report on the mammographic and sonographic imaging and pathological findings of a low grade , primary breast fibrosarcoma . a 47-year - old woman presented with a painless palpable mass in her left breast . a physical examination revealed a 3 cm size , relatively well - defined mass in the upper outer quadrant of the left breast . the mammograms showed a 3 cm , ovoid , partially obscured , partially circumscribed , and high - density mass without internal calcifications in the upper outer quadrant of the left breast ( figure 1a , b ) . a sonogram showed a 2.5 cm , ovoid , circumscribed and homogeneous hypoechoic mass with posterior acoustic enhancement at the 2 o'clock site of the left breast ( figure 1c ) and color doppler image showed vascularity in the peripheral portion of the mass ( figure 1d ) . we therefore classified the mass as category 4b according to the breast imaging reporting and data system ( bi - rads ) . we then performed an ultrasonographic - guided core needle biopsy , and the histopathological examination of the biopsy specimen revealed the presence of a cellular , spindle cell proliferative neoplasm with intermittent mitosis . these findings did not allow differentiation between spindle cell mesenchymal neoplasm and fibroepithelial neoplasm , and the findings could not provide a diagnosis . therefore , surgical excision was performed , and the gross specimen showed a firm , fleshy , well circumscribed , round mass that was gray - white and it measured 3.5 cm at the greatest dimension . histopathological examination showed a high cellular , spindle cell tumor that displayed an interdigitating fasciculated growth pattern , the so - called herringbone pattern ( figure 2a ) . the tumor cells were fusiform or spindle shaped cells that varied little in size and shape , and they had scanty cytoplasm with indistinct cell borders . the mitotic activity was up to 9 - 10 per 10 hpf ( figure 2b ) . the negative immunostaining results for s-100 protein , smooth muscle actin and many kinds of keratin , including ck ae1/ae3 , high molecular weight ck , low molecular weight ck , ck7 and epithelial membrane antigen , distinguished this tumor from spindle cell malignant melanoma or malignant peripheral nerve sheath tumors , leiomyosarcoma and metaplastic carcinoma ( figure 2c ) . she had no postoperative complications , and she remains well without signs of local recurrence or distant metastases 10 months following her surgery . pure stromal sarcoma of the breast includes fibrosarcoma , malignant fibrous histiocytoma , liposarcoma , rhabdomyosarcoma , leiomyosarcoma , hemangiosarcoma , malignant schwannoma , osteogenic sarcoma and chondrosarcoma . adult fibrosarcoma is a malignant tumor that is composed of fibroblasts with variable degrees of collagen production and in classical cases a herringbone architecture , according to the world health organization . fibrosarcomas can occur anywhere in the body , but they usually occur primarily in the extremities . .   reviewed only 25 cases of primary breast sarcoma that were diagnosed pathologically at a london hospital during an 80-year period . among these the peak incidence of primary breast sarcoma occurs in the fifth and sixth decades of life . however , roberson   has reviewed the literature and evaluated 49 reported patients with fibrosarcoma of the breast , and half of them were between the ages of 41 and 60 . these patients usually present with a complaint of a lump in one breast of two to six months duration and pain was present in over one - third of the cases . in contrast , the clinical presentation of a common primary breast sarcoma is a painless breast lump . the size of primary breast sarcomas is variable and it ranges from less than 1 cm to larger than 40 cm . the prognosis is usually based on the size of the tumor and the histological grade . the stromal sarcomas were classified as malignant fibrous histiocytomas ( 11 cases ) , fibrosarcomas ( 2 cases ) , leiomyosarcomas ( 2 cases ) and liposarcoma ( 1 case ) . in that study , the metastasis - free survival rate was significantly correlated only with the histological grade , which consisted of the tumor differentiation , the presence of tumor necrosis and the mitotic activity . the clinical courses and survival of the cystosarcoma and stromal groups were identical , which raises questions about the clinical value of this pathologic distinction . all the local recurrence , metastasis or death occurred within 30 months , although the follow - up was much longer . of the 55 patients , 17 had breast - conserving therapy and 38 women had mastectomy . the mean patient age at presentation was 52 years ( range , 22 to 82 years ) . the types of sarcoma included angiosarcoma ( 18 ) , malignant fibrous histiocytoma ( 11 ) , stromal sarcoma ( 8) , liposarcoma , leiomyosarcoma , dermatofibrosarcoma protuberans ( 4 ) , osteosarcoma ( 3 ) , fibrosarcoma ( 2 ) and rhabdomyosarcoma ( 1 ) . follow - up information was available for 53 patients with a mean follow - up of 81 months . twenty - nine of the 53 patients ( 55% ) developed recurrent sarcoma and 23 patients ( 43% ) died of their disease . twenty - seven patients had no evidence of recurrence , and 3 patients were alive with disease at the last follow - up . twelve of 18 patients ( 67% ) died of angiosarcoma , compared with 11 of the 32 patients ( 34% ) with all the other types of sarcomas combined . of the 34 patients who did not receive adjuvant chemotherapy or radiation , 13 died of their disease ( 38% ) , as compared with 10 of the 16 patients ( 63% ) who did receive adjuvant therapy . in that study , elson et al .   reported the mammographic findings of 5 cases with fibrosarcoma of the breast . in their study , the mammograms showed high - density masses with margins varying from poorly defined to well - defined and the diameters ranged from 1.5 cm to 7.0 cm . calcified osseous elements were present in 1 of the masses . however , these findings were nonspecific . in the case presented here , the mass appeared as an ovoid , partially obscured and partially circumscribed , high - density mass on mammography and this is also a nonspecific finding and it could not distinguish fibrosarcoma from other breast carcinomas . on ultrasonography , the mass appeared as an ovoid , circumscribed and homogeneous hypoechoic solid mass with posterior acoustic enhancement . in our patient , the size of the tumor was 3 cm and there was no lymph node or distant metastasis . the tumor stage was a 1a according to the american joint committee on cancer . according to the national comprehensive cancer network clinical practice guidelines in oncology , surgery is the primary treatment for low - grade stage 1 tumors and it is considered definitive if the tumor free margins are greater than 1 cm or the fascia plane is intact . for surveillance , stage i tumors are routinely followed with taking the recent medical history and conducting a physical examination every 3 - 6 months for 2 - 3 years and then annually . chest imaging should also be considered every 6 to 12 months . because these patients ' risk never returns to zero , long - term follow - up is indicated and this should include mri or ct scanning . if the final tumor - free resection margins is 1 cm or less , then radiotherapy should be considered . in our case , local recurrence and distant metastasis did not occur in our patient 10 months after surgery . in conclusion , fibrosarcoma of the breast is a rare tumor and the imaging results make it difficult to differentiate this type of lesion from other malignant masses .
a primary fibrosarcoma of the breast is a rare tumor . here 
 we report on a case of a primary fibrosarcoma of the breast that presented as a palpable left breast mass in a 47-year - old woman . 
 the physical examination revealed a 3 cm sized , round mass in the left upper outer breast . 
 the mammograms revealed a 3 cm sized , partially circumscribed and partially obscured , high density mass in the upper outer quadrant of the left breast . 
 an ultrasonogram demonstrated a 3 cm sized , ovoid , circumscribed and hypoechoic mass with peripheral increased vascularity on doppler imaging . 
 surgical excision was performed and the pathology revealed a low grade fibrosarcoma .