Introduction: Metastases to the skin are relatively rare, but they are an important diagnostic and therapeutic challenge. In women skin metastases are the most commonly associated with breast cancer. In the men they are often associated with lung cancer. Skin metastasis most often are in form of blue-purple nodules and tumours with tendency of necrosis.

Aim: The aim of this paper is to present the case of a patient with diagnosed breast cancer with skin involvement.

Case report: The 48-years old female patient was admitted to The Department of Dermatology for diagnosis and treatment of dermal lesions in form of numerous blue-purple nodules and ulcerations localised on the skin of the chest. The ultrasound examination suggested a primary malignant lesion in the left breast spreading to the right side and numerous satellite nodules. A whole nodule was collected for histopathological and immunohistochemical examinations in order to make the final diagnosis. Histopathology tests confirmed the diagnosis of tumour metastases of the skin and positive immunohistochemical reactions for cytokeratin 7 (CK7) and for oestrogen receptors (ER) pointed mammary glands as the primary site. The patient was urgently referred to the Oncology Centre.

Conclusions: The occurrence of skin metastasis in all tumour processes significantly worsens the prognosis of the patient. These changes should be quickly recognized by the oncologist or dermatologist. Sometimes the localization of primary tumour is not possible to determine without taking the biopsy for histopathological and immunohistochemistry assays. Rapid treatment of appropriate chemotherapy or radiotherapy can prolong life and reduce pain.