Malignant eccrine breast spiradenoma. A case report and literature review

• Eccrine 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.

IntroductionEccrine spiradenomas are rare adnexal tumours of the skin that originate in the sweat glands. There are only three cases, including ours, diagnosed as malignant transformation in the breast.Presentation of caseWe present a case of an asymptomatic 48 year old woman in whom the lesion was detected on the basis of breast cancer prevention programme. The metastatic study detection and the sentinel lymph node biopsy were negative so wide excision of the mass was performed with no further treatment. After 32 months of follow-up, there is no evidence of recurrent or metastatic disease in our patient.DiscussionThe lesions usually show a typical history of a long-standing unchanged cutaneous solitary nodule that becomes enlarged. The imaging findings of breast eccrine spiradenomas have not been clearly demonstrated. Diagnosis is based in histopathological findings of malignant focus.A large list of uncommon dermatological skin malignancies and breast benign lesions can mimic malignant eccrine spiradenomas (MES); therefore, determination of inmunophenotype allows narrowing differential diagnosis. Distant metastases portend an ominous prognosis. The mainstay of treatment is surgical removal with wide excision margins. Radiation and hyperthermic chemotherapy can also be administered to prevent focal recurrence. Due to the high risk of developing metastases, close follow up of these patients for early detection of recurrence should be carried out.ConclusionEccrine spiradenomas are rare adnexal tumours of the skin. Intraparenquimatous breast location is especially infrequent. Diagnosis is based on histopathological examination. MES metastasizes (40%), so a close follow up is recommended.