A rare case of Merkel cell carcinoma of the eyelid

An 80-year-old man presented at the Eye Clinic of the University of Trieste for evaluation of a rapidly growing left superior eyelid lesion. Past ophthalmologic history was positive for cataract extraction with IOL implantation, performed some years previously. The patient’s medical history was also positive for chronic renal insufficiency, atrial fibrillation, and ischemic heart disease. The patient had undergone excision of a squamous cell carcinoma located on the scalp and several treatments for actinic keratosis, indicating a tendency to develop sun exposure–related tumors. The oculoplastics specialist reported a nodular, tender, elastic lesion, measuring about 1.9 × 1.2 cm and not easily mobile, located just inferior to the lateral third of the left brow (A). The overlying skin was hyperemic, with local telangiectatic vessels. There were no signs of infection and no pain or tenderness. Ultrasonography and Doppler ultrasonography (B) showed a hypoechogenic, 1.2 × 0.7 × 0.5 cm, solid, highly vascularized mass. After surgical resection, pathological evaluation was performed and revealed a “small blue round cell tumor” in the dermis (C [hematoxylin and eosin]), characterized by the following immunohistological essay: CK-20 (D) and BerEp-4 positivity, p-63, CK-5 and CK-6 negativity, high Ki-67 percentage. These findings were consistent with a diagnosis of Merkel cell carcinoma, a very rare and aggressive skin tumor, which occurs infrequently in the periocular region.