Skin metastasis from many cancers may occur during the course of disease. The majority of skin metastases develop as a result of direct invasion of the cancer but sometimes, hematogenous or lymphogenous metastases may develop as in breast, lung, gastrointestinal tract cancers and soft tissue sarcomas. Breast cancer is the most common cause of skin metastases in women. The skin metastasis of breast cancer usually develops as nodular lesions which settle down from the primary tumor area. Herein, we report a case of widespread erythematous skin metastasis from breast cancer, without visceral involvement. [Turk J Cancer 2009;39(2):66-68]

Cutaneus metastasis may occur during the course of many cancers. Breast, lung, and gastrointestinal cancers are the most frequent causes of skin metastasis[1]. Overall incidence of skin metastasis is about 5%[1]. Skin metastasis from breast cancer is usually nodular occurring during the late stages of the disease. Only a few reports of erythematous widespread skin metastasis from breast cancer have appeared in the literature[2]. We report a case with erythematous widespread skin metastasis from breast cancer without any visceral involvement.

Fifty five years old, postmenopausal woman suffering from widespread pruritic skin lesions, was admitted to the hospital. She had left modified radical mastectomy 3 years ago for infiltrative ductal breast carcinoma. The tumor was negative for estrogen and progesterone receptors, and c-erb b2 expression was also immunohistochemically negative. Following adjuvant treatment the patient relapsed with a cutaneous nodule 2 years later. A combination chemotherapy including docetaxel plus epirubicine was started for palliative aim. On the 7^th day of the third cycle, she was admitted to the hospital suffering from widespread erythematous skin lesions. The skin lesions were pruritic and painless. She had no history of hypersensitivity to any drug and she did not receive any drugs other than chemotherapy regimen mentioned above. Widespread small erythematous papular skin lesions on entire trunk, and a nodular lesion of 3x2 cm in diameter near the right side of the sternum were noted on physical examination (Figure 1). Systemic dexamethasone and oral antihistaminic were started for the clinical diagnosis of drug eruption but there was no improvement within 10 days of treatment. Skin biopsy was performed from right upper back, which was far away from the area of local recurrence, and it revealed the small solid groups of malignant epithelial cells, predominantly located in papillary dermis, which were consistent with the metastatic invasion (Figure 2). There was no metastatic lesion on computed tomographies of abdomen and thorax. Mitomycin-C plus vinorelbine were given. Following 2 cycles of this regimen, the majority of the skin lesions were improved (Figure 3). She is still alive for fourteen months after the diagnosis of skin metastasis, and is still being treated with mitomycin-C and vinorelbine combination chemotherapy.

Fig 1: Widespread erythematous skin lesions and local nodular recurrence of breast cancer (black arrow) before mitomycin-C plus vinorelbine treatment

Fig 2: Small solid group of malignant epithelial cells located in the papillary dermis. The central portion of the group was showed necrosis and apoptosis (H&E;, x200)

Fig 3: Following 2 cycles of mitomycin plus vinorelbine, majority widespread erythematous skin lesions were improved

Cutaneous metastasis may occur in the course of any malignancies but diffuse involvement of the skin is not frequent. Skin metastasis from breast cancer is usually nodular and locally relapsing type. Furthermore skin metastasis may associate visceral involvement in the advanced stage of disease. Few reports of widespread erythematous skin metastasis from breast cancer have appeared in the literature[3]. Docetaxel may cause cutaneous side-effects such as acral erythema or fixed erythematous plaque[2]. In our case, the skin lesions were initially thought as drug eruption from any cause; chemotherapy and/or chemotherapy complementary drugs such as antiemetics. To distinguish the skin metastasis from local recurrence, the biopsy was performed from right upper back which was far from the area of local recurrence. Likewise, improvement of the skin lesions by chemotherapy is also in favor of skin metastasis from breast cancer. Other malignancies may also present with skin lesions, but there were no signs and symptoms supporting secondary malignancies. The diffuse skin metastases are generally associated with visceral metastases, but there was no visceral involvement in our case[3]. The skin metastasis is treated locally or systemically while the widespread skin lesions in a patient with ER/PR negative tumor can be treated with systemic chemotherapy as in present case. In conclusion, widespread erythematous skin lesions resembling drug eruptions in patients with history of breast cancer may be due to skin metastasis as in the present case.