Exophytic Parietal Skin Metastases of Renal Cell Carcinoma

The common sites for metastasis of renal cell carcinoma are lung, kidney, adrenal glands, liver, and contralateral kidney. We report an unusual case of cutaneous metastasis of renal cell carcinoma in a 68-year-old woman who was treated for renal cell carcinoma with partial right nephrectomy and multikinase angiogenesis inhibitor (sunitinib) 10 years ago. 1. Introduction Renal cell carcinoma (RCC) accounts for 90% of all renal tumours in adults. Approximately a third of patients with RCC develop distant metastases to lungs, liver, bones, adrenal glands, or contralateral kidney. Cutaneous metastasis accounts for 6% of metastatic RCC [1] and depicts a poor prognosis [2]. Cutaneous metastasis has been described in head and neck [3], genital [4], torso [5], and limbs [3]. This case report described an unusual cutaneous manifestation of metastatic renal cell carcinoma in a 68-year-old woman 10 years after partial right nephrectomy and treatment with multikinase angiogenesis inhibitor (sunitinib). 2. Case Report A 68-year-old Caucasian woman was referred to our Oral & Maxillofacial Surgery Department from a Dermatology unit in October 2012 for assessment and removal of an exophytic lesion located on the left parietal area of the scalp. The lesion was growing in size but, otherwise, asymptomatic. She was previously diagnosed with renal cell carcinoma. Examination revealed a lesion of pulsatile nature with centrally raised and indurated lesion, red purplish in colour measuring approximately 4？cm in diameter. Our differential diagnoses included angioma, basal cell carcinoma, and cutaneous horn. A CT head scan shows that there is no involvement of the skull vault. Urgent blood tests were arranged which revealed hypercalcaemia (2.95？mmol/L) and anaemia (7.2？g/dL) which were highly suggestive that the lesion on the parietal scalp could be distant metastasis of renal cell carcinoma. Urgent excision of the lesion was arranged and the histopathology findings were consistent with metastatic renal cell carcinoma. 3. Presentation 3.1. Macroscopic Description (Figures 1(a) and 1(b)) Figure 1 Red-purplish in colour with centrally raised area measuring 2 × 1.3？cm with a well circumscribed base of 3.5 × 1.5？cm. In situ, it was solid and pulsatile in nature. 3.2. Histology Description Histology revealed a focal area of ulceration on the epidermis. The dermis contained circumscribed tumour deposits (Figure 2(a)). The tumour deposit featured nests of cells with moderate amount of well-defined clear cytoplasm with round to oval nuclei. It also showed foci of vascular invasion