only a few cases have been reported , being described for the first time by kersting and helming . though the majority of eccrine spiradenomas involve the head , trunk , and extremities , they can also appear all throughout the skin , mostly as painless solitary nodules . our case report is a malignant eccrine spiradenoma ( mes / spiradenocarcinoma ) diagnosed in an asymptomatic woman on the basis of breast cancer prevention programme . because of its rare incidence and lack of imaging workups our aim is therefore to discuss the main characteristics of it , and to review the literature available on this issue . a 48-year - old woman , asymptomatic , with no medical history of interest , presented in a mammography made as part of a breast cancer screening programme a lesion in the left upper - breast . 1 ) demonstrated a well - defined , isodense nodule located in the upper - outer quadrant of the left breast . longitudinal and transverse scans with colour doppler images were obtained . the images ( fig . 2 ) showed a well - defined lobulating mass measuring 18    13    15  mm with homogeneous hypo echogenicity . in the colour doppler sonography a histologic examination of these showed a characteristic biphasic population of outer small cells with darkly staining nuclei surrounding larger cells with pale cytoplasm without epidermal connection . intraoperative radiologic control of the excised lesion showed integrity of the nodule with broad resection margins . macroscopically the sample measured 4    2.5  cm in which on serial sectioning a 2    1.5  cm white nodule was noted . microscopic examination showed cells arranged in ragged sheets , nests , cords , and solid masses along with occasional irregular glandular structures . benign areas , was seen as sharply demarcated lobules composed of 2 cell populations ( peripheral basaloid cells and central pale cells ) arranged in nests with focal cystic changes . adjoining to this 2-cell population focus ( gradually or abruptly ) proliferation cells with histopathological malignant characteristics transited to solid masses of a homomorphous large cell population with hiperchromatic and pleomorphic nuclei , eosinophilic cytoplasm ( fig . inmunohistochemically , both cellular areas exhibited p63 and were positive for smooth muscle actin ( sma ) . focal reactivity for ema and cea was found in the central , large , pale cells . luminal cells expressed muc-1 , ck 7 , ema , cea , ck cam5.2 and gcdfp-15 . around 4050% of the cells composing the carcinomatous area showed positivity to ki-67 ( fig . s-100 , ck 20 , vimentin , cd3 , cromogranin and ck34betae12 , estrogen / progesterone receptors were not expressed . these features were consistent with a low - grade mes noted to be arised from a pre - existing benign long - standing eccrine spiradenoma . the sentinel lymph node retrieved from axillary dissection was submitted for intraoperative histological examination obtaining a negative result for metastatic carcinoma . metastatic workup detection ( bone scan , computed tomographic scans of the chest , abdomen , and pelvis ) was also negative . the patient has been seen in follow - up every 36 months and has had yearly sonographic examinations . after 32 months of follow - up , there is no evidence of recurrent or metastatic disease . eccrine spiradenomas are usually benign , well - defined sweat - gland neoplasms that affect both men and women , showing no sex predilection ( male to female ratio 1:1 ) . age at presentation is variable , but most commonly arising at an age of 50 . spiradenoma lesions tend to arise on the head ; neck ; trunk ; and , less commonly , the arms followed by the legs . however , the development of neoplasms with eccrine sweat gland phenotype in the mammary ducts is not surprising in as much as the breast is considered a modified sweat gland . since the original report , 102 cases of mes   have been documented in the literature . of these , only six are described affecting the breast . there are only three cases , including ours , diagnosed as malignant transformation in the breast ( table 1 ) . although , four of the five cases of breast spiradenomas were benign , 2 of these were reported to suffer malignant transformation , and one carcinosarcomatous conversion . reviewing the reports , the lesions usually show a typical history of a long - standing ( often decades ) ; unchanged cutaneous solitary nodule that suddenly becomes enlarged . the average size of malignant spiradenomas at presentation is 3.9  cm ( range 0.515  cm ) in diameter , but usually 12  cm   as in our patient . it generally begets medical attention when a pre - existing undiagnosed lesion rapidly enlarges , changes colour , ulcerates , or becomes painful and tender . the imaging findings of breast eccrine spiradenomas have not been clearly demonstrated because of the rare incidence of eccrine spiradenomas and the lack of imaging workup . the findings reported were : round or oval shape , well - demarcated masses hypo , or hyper - dense in mammography . the us findings of the current case were characterized as well - circumscribed , oval - shaped , hypoechoic masses , surrounded by echogenic lines that represent the dermal layer . reported the first description of the sonographic findings of a mes in 1993 as a hypoechoic , heterogeneous lesion . mri , ct , and radiography can be used to assess the presence of metastatic foci in the case of malignant spiradenoma . although , an eccrine spiradenoma may resemble an epidermal inclusion cyst on mammography and us , these may be identified on the basis of mri findings . the mri   findings of epidermal inclusion cysts and eccrine spiradenomas are different [ 810 ] and so they might be used in making the differential diagnosis . diagnosis of mes is based on histopathologic   examination and requires finding a focus of benign spiradenoma within or adjacent to the malignant tumour . nowadays , high - grade tumours show multiple foci of florid squamous differentiation , including proliferation of solid masses consisting of large cells with hyperchromatic nuclei , loss of pas - positive basement membrane , sarcomatous cell metaplasia and surrounding cell reaction . the mesenchymal elements are non - specific and are often described as rhabdomyosarcoma , osteosarcoma , leiomyosarcoma , and chondrosarcoma . on the other hand , in the absence of a benign focus , tumours can be confused with other skin malignancies . the diagnosis of these is much more difficult and requires finding benign focus on histopathology and an inmunohistochemical myoepithelial benign profile in consonance with the finding of two cell populations . in our case , histologically proliferation of cells with hyperchromatic pleomorphic vesicular nuclei , variably prominent nucleoli , increased mitoses , invasion of surrounding membrane and adipose mammary tissue characterized malignant transformation . inmmunohistochemically , the cells express immunophenotypes similar to mioepithelial cells with a variable expression of p63 and sma , and ductal differentiation cells expressing cea , ema , ck7 , muc-1 , ckcam5.2 y gcdfp-15 . s-100   protein positivity in basal epithelial cells has been demonstrated , but was not evidenced in our case . we also identified ki-67 and d1-cyclin expression , as a result of a low - grade differentiation tumour . while the inmmunohistochemical profile of benign or malignant eccrine spiradenoma is not diagnostic of an eccrine neoplasm , it is helpful in elucidating the cellular differentiation and narrowing the differential diagnosis . radiation and hyperthermic chemotherapy can also be administered as medical treatment to prevent focal recurrence . in our case , malignant eccrine spiradenoma metastasizes ( 40% )   to regional lymph nodes , bone , lungs , brain , and liver   ( in descending order of frequency ) . distant metastases portend an ominous prognosis , but if possible , resection should be done . we did not implement an axillary dissection , as sentinel node biopsy turned out negative . due to the high risk of developing metastases , close follow up of these patients for early detection of recurrence should be carried out . malignant eccrine spiradenoma metastasizes ( 40% ) , so a close follow up is recommended . the authors declare that there is not any source of funding for this surgery case report . written informed consent was obtained from the patient for publication of this case report and accompanying images . francisco villalba ferrer , andrs garca vilanova , carlos fuster diana , jose medrano gonzlez : surgery , follow up and surgical comment on the clinical case .
highlightseccrine spiradenomas are rare adnexal tumors of the skin . 
 malignant transformation of benign forms is even more unfrequent.we report a case of malignant breast eccrine spiradenoma diagnosed on the basis of breast cancer prevention programme.imaging findings of these tumors have not been clearly demonstrated because of the rare incidence and lack of workup.the mri findings of epidermal inclusion cysts and eccrine spiradenomas are different and so these findings might be used in making the differential diagnosis .