Primary Cutaneous Mucinous Carcinoma Monitoring: A Role for CA15.3 and CEA?

Primary cutaneous mucinous carcinoma (PCMC) is a rare malignant skin adnexal tumor. Recurrences are most often localized, and long-term follow-up after complete surgery consists essentially of self-examination of skin. We report one case of metastatic PCMC with elevated levels of serum CEA and CA15.3. Because of the difficulty to differentiate PCMC and metastasis of mucinous breast cancer, the hypothesis of a metastasized breast cancer was ruled out. These tumor markers contributed to the monitoring of the metastatic disease. Since metastatic disease was diagnosed after several years of seeming complete remission, CEA and CA15.3 would likely have allowed the clinicians to detect the relapse earlier. Although the use of tumor biomarkers in PCMC is not rooted in clinical practice and not mentioned in guidelines, we suggest that CEA and CA15.3 could be of particular interest to monitor and detect early metastatic PCMC.