If You Aren’t Looking, You Won’t See It—a Distinctive Clinical and Histopathologic Presentation of Renal Cell Carcinoma Metastasis to the Eyelid and Brief Review of the Current Literature

Renal cell carcinoma (RCC) most commonly metastasizes to the lungs, liver, and bone, with cutaneous metastases occurring at an estimated incidence of 3.4% to 4.0%. Renal cell carcinoma metastases to the eyelid are even more rarely reported and have generally been described to present as a well-circumscribed nodule that maintains the characteristic histological features of the primary tumor. We report an unusual case of metastatic RCC to the eyelid with unique clinical and histopathologic features. On clinical examination, the patient presented with an indurated “rash” of the eyelid that clinically resembled orbital contact dermatitis. Histological examination showed inconspicuous tumor cells infiltrating the dermis, instead of the more characteristic “clear cells” seen in the patient’s primary tumor. Tumor cell origin was confirmed immunohistochemically by positive pan-cytokeratin (AE1/AE3), CK18, CAM5.2, epithelial membrane antigen, CA-IX, PAX2, and PAX8. The case is described and followed by a pertinent discussion of clinical, histopathologic, and immunohistochemical features of cutaneous metastases.