peritoneal neoplasm (MONDO_0006901) is a benign or malignant neoplasm that affects the peritoneal cavity. Representative examples of benign neoplasms include adenomatoid tumor and disseminated peritoneal leiomyomatosis. Representative examples of malignant neoplasms include primary peritoneal carcinoma, metastatic carcinoma to the peritoneum, and malignant mesothelioma. Also known as: neoplasm of peritoneum, peritoneum neoplasm, peritoneum neoplasm (disease), peritoneum tumor, peritoneum tumour, tumor of peritoneum, tumour of peritoneum.