Low-grade neoplasms

Low-grade neoplasms

Most epithelial tumours of the appendix are classified as LAMNs. These lesions demonstrate minimal cytological Laura H Tang , contemporary , pathologist, Memorial Sloan Kettering Hospital, New Y ork, NY , USA. atypia and are characterised by pushing rather than infil - trative invasion without evidence of destruction. In the case of appendix perforation, mucin may be found outside the appendix, the significance of which is increased when accom - panied by the presence of epithelial cells. Low-grade tumours do not typically metastasise to regional lymph nodes and as - such right hemicolectomy is not required. The importance of these lesions lies in their propensity to disseminate thr oughout the peritoneal cavity , causing the syndrome known as PMP . Patients with low-grade epithelial neoplasms and no evidence of mucin or epithelial cells beyond the appendix are thought to be at low risk of future PMP development. A colonoscopy should be performed to exclude associated colonic epithelial lesions and patients entered into a surveillance protocol for at least 5 years. Surveillance may take the form of clinical review , annual low-dose abdominopelvic CT scan and monitoring of appendix-related tumour markers (carcinoembryonic anti - gen [CEA], CA-19-9, CA-125). In patients with perforated tumours, particularly when extraluminal mucin contains epithelial cells, the risk of PMP is higher. In some experienced ed for cytoreductive centres these patients may be consider surgery with hyperthermic intraperitoneal chemotherapy - (HIPEC), although a common approach is regular monitoring for the appearance of clinical or radiological features of PMP , which would then warrant surgery .