Cutaneous Manifestations as a Sentinel of Colorectal Cancer: A Case Report.

Erythema gyratum repens (EGR) is a rare figurate erythema strongly associated with internal malignancy and recognized as one of the most specific cutaneous paraneoplastic syndromes. Its recognition is clinically important, as it frequently precedes the diagnosis of an underlying neoplasm. We report the case of an 80-year-old woman who presented to the emergency department with a rapidly progressive, intensely pruritic eruption displaying a characteristic concentric "wood-grain" pattern. Laboratory evaluation revealed iron-deficiency anemia. Contrast-enhanced computed tomography identified a right-sided colonic mass, and colonoscopy with biopsy confirmed adenocarcinoma of the cecum. The patient underwent elective laparoscopic right hemicolectomy with complete tumor resection (pT3N0, microsatellite stable). Following surgery, the cutaneous lesions resolved completely and did not recur during follow-up. This case highlights erythema gyratum repens as a clinically relevant early marker of colorectal cancer and emphasizes the importance of prompt recognition of this distinctive dermatosis to trigger urgent and comprehensive malignancy screening, enabling timely diagnosis and definitive treatment.