• Two cases in the manner of the reported patient. • Two cases presenting as dramatic perforation and peritonitis after profuse anaesthetic-induced vomiting within 24 h of surgery for unrelated conditions. • Two cases of pseudomyxoma peritonei (PMP). The mucinous tumours of the appendix have deceptive histology and controversial biology. Their progress to PMP may occur by asymptomatic leakage of the implanted material. 2 This is usually an indolent process, unlike the other mucus-producing peritoneal adenocarcinomas of stomach, bowel, pancreas and mesothelioma, which are part of a differential diagnosis. They can however rupture suddenly and present as an acute abdomen. Surgeons should be wary of large distended appendixes, and excise them without spillage, and preferably after computed tomography scan information, which may allow a tentative diagnosis and a planned open hemicolectomy. At emergency laparoscopy for perforation, the spilled mucus is iridescent, which suggests the diagnosis. The modern approach to the management of PMP is with detailed clinical, radiological and histopathological assessment. Cytoreductive surgery and heated intraperitoneal chemotherapy in specialist centers offer hope for advanced disease. 3