CUTANEOUS METASTASIS IN A PATIENT WITH COLORECTAL CANCER: A CASE REPORT

Case Presentation A male patient, E.A.M.G., 59 years old, sought medical attention in November 2022, reporting bright red blood in his stool and weight loss. A colonoscopy was requested, revealing an ulceroinfiltrative lesion in the mid-rectum, affecting 50% of the circumference. Histopathological examination (HE) showed a well-differentiated ulceroinvasive adenocarcinoma of the rectum. Tumor staging showed no distant metastasis. He was referred to oncology and underwent neoadjuvant chemoradiotherapy, followed by a rectosigmoidectomy with primary anastomosis and loop transverse colostomy. During the surgery, no metastasis was observed, and HE revealed no angiolymphatic or perineural neoplastic invasion, with clear circumferential and distal surgical margins (pT2 pN0). In November 2023, the patient returned, reporting a lesion in the perianal region. On physical examination (PE), a single 4 cm, purple, painless, and mobile nodule was observed perianally. The lesion was excised, and HE confirmed moderately differentiated ulcerated adenocarcinoma in the skin at the anal margin. There was no neoplastic invasion, angiolymphatic, or perineural involvement, and surgical margins were free, with the closest margin being 3 mm.

Discussion Colorectal cancer (CRC) is the fourth most common malignancy globally and the most frequent in the gastrointestinal tract (GIT). The general incidence of cutaneous metastases from gastrointestinal malignancies is 5.3%, and most of these metastases are located near the primary tumor site. The mechanisms for the occurrence of cutaneous metastases have not been definitively established, but they may appear through the peritoneal cavity or the lymphatic and hematologic systems. Iatrogenic implantation during surgery is rare. Metastatic carcinoma appears as violet or skin-colored, firm, freely movable, painless nodules, which can be solitary or multiple. They are mainly classified as adenocarcinoma, squamous cell carcinoma, and undifferentiated carcinoma. Local wide excision of the cutaneous metastatic lesion is the preferred treatment option, and in extensive cases, the treatment is palliative.

Conclusion Cutaneous metastases from CRC are a rare manifestation, making it crucial to evaluate cutaneous lesions in patients with a history of CRC. Therefore, there is a need for physicians to educate and train patients on skin examinations, detecting any changes, and early reporting of any cutaneous alterations, especially in individuals with a history of visceral malignancy. By promoting a comprehensive understanding of this phenomenon, physicians can contribute to better detection, intervention, and care for individuals with a history of CRC.

Publication History

Article published online:
25 April 2025