ABSTRACT
This chapter aims to provide an overview of peritoneal malignancy from a pathological perspective and covers primary and metastatic peritoneal neoplasms that are most likely to be treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Low-grade appendiceal mucinous neoplasm has low-grade epithelium that can show villous, undulating or flattened architecture. Mucinous adenocarcinomas of the appendix are defined by infiltrative invasion. Areas resembling adenomatoid tumour are common, and some cases also show areas of Well-differentiated papillary mesothelioma. Ovarian serous borderline tumours and low-grade serous carcinoma share many characteristics and are histologically and biologically distinct from high-grade serous carcinoma. Given the importance of identifying and grading cells within pseudomyxoma peritonei, the limitations of small biopsies need to be recognised. Histologically, clear cell carcinoma is typically characterised by pleomorphic cells with clear cytoplasm forming solid, tubular, cystic or papillary patterns.
