Multicystic peritoneal mesothelioma mimicking recurrent pseudomyxoma peritonei.

Multicystic peritoneal mesothelioma (MCPM) is a borderline variant of peritoneal mesothelioma with indolent behaviour but a significant recurrence rate without radical treatment. Due to its rarity, risk factors and optimal treatment are still to clarify. The present clinical case is a report of MCPM developed after laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (Lap CRS-HIPEC) for pseudomyxoma peritonei (PMP) of appendiceal origin. The patient was treated for PMP with Lap CRS-HIPEC. One year later a recurrence was suspected at the thorax-abdomen computed tomography scan. After multidisciplinary discussion, she underwent iterative Lap CRS-HIPEC. Pathological examinations revealed MCPM. After 3 years of follow-up the patient is disease-free for both tumours. This is a unique case of MCPM mimicking recurrent PMP. Lap CRS-HIPEC is an effective approach for both conditions.