Metastatic Cutaneous Squamous Cell Cancer with Peritoneal Carcinomatosis: A Case Report

Peritoneal involvement as a metastatic site of squamous cell skin cancer is exceptionally rare. The current work analyzes a 52-year old male with high-risk cutaneous squamous cell nose carcinoma (cSCC) that was initially treated with surgery and platinum-based concurrent chemoradiation. Five years later, he presented jaundice and hypercalcemia. Further imaging revealed diffused liver, peritoneal and paraaortic lymph node metastases without evidence of locoregional recurrence. The patient underwent liver biopsy, which confirmed the diagnosis. High-risk features for metastasizing can be considered the maximum clinical diameter, the anatomical subsite (localization of the primary tumor in the ear and retroauricular area, cheek and lip are considered to significantly increase the risk of distant metastasis), poor histological differentiation, perineural invasion and lesions with a thickness of more than 2.0 mm. Late relapse that involves only disseminated abdominal disease is very uncommon and may justify closer follow-up and more aggressive chemotherapy in high-risk patients.