Appendiceal Mucinous Adenocarcinoma Research Articles

Pseudomyxoma peritonei in a hernia sac: analysis of 20 patients in whom mucoid fluid was found during a hernia repair

Introduction Pseudomyxoma peritonei syndrome is a rare disease that causes extensive accumulation of non-invasive mucinous tumour and mucinous fluid throughout the abdomen and pelvis. The primary tumour is a perforated appendiceal adenoma or mucinous adenocarcinoma. In patients with an open processus vaginalis or other peritoneal defect, the adenomatous epithelial cells may accumulate within the hernia sac, causing mucoid fluid to be present at the time of hernia repair. Materials and methods From February 1991 to September 1997, the diagnosis of pseudomyxoma peritonei syndrome was established in 20 patients in whom mucoid material was found in a hernia sac during a hernia repair. Clinical features of these patients were critically evaluated using the completeness of cytoreduction as an endpoint. Results The treatments delivered at the time of hernia repair had no impact on the outcome. A lack of interim events vs the use of interim treatments between hernia repair and definitive cytoreduction was significant in relation to a complete vs incomplete cytoreduction. Non-aggressive histology and an interval of less than 1 year was statistically significantly associated with a favourable outcome from surgical intervention. Conclusion When mucoid fluid is encountered at the time of a hernia repair, recovery of that fluid and the hernia sac for histologic study is important. When adenomatous epithelial cells are present, a CT scan should be performed to look for the typical distribution of mucinous tumour and fluid that suggests the pseudomyxoma peritonei syndrome. If the diagnosis can be confirmed, referral to a centre experienced in the treatment of this rare disease is suggested.

The morphologic spectrum of ovarian metastases of appendiceal adenocarcinomas: a clinicopathologic and immunohistochemical analysis of tumors often misinterpreted as primary ovarian tumors or metastatic tumors from other gastrointestinal sites.

Twenty cases of ovarian metastases derived from appendiceal adenocarcinomas were analyzed. The most common presentation was a pelvic mass. The appendiceal and ovarian tumors were diagnosed concurrently in 15 cases; in the remaining five, the ovarian tumors were diagnosed before the appendiceal tumor. The appendiceal adenocarcinomas demonstrated four morphologic patterns: 1) signet ring cell type, with or without glandular or goblet cell differentiation (14 cases); 2) mixed signet ring cell and intestinal type (two cases); 3) intestinal type (two cases); and 4) typical colorectal type (two cases). The ovarian tumors were bilateral in 16 cases and were histologically similar to the associated appendiceal tumor in each case. Ovarian metastases that demonstrate signet ring cell, glandular, and goblet cell differentiation mimic metastases from gastric adenocarcinoma. Those that are derived from well-differentiated mucinous appendiceal adenocarcinomas mimic primary ovarian mucinous tumors and metastases from the pancreas and biliary tract. Metastases of appendiceal adenocarcinomas of colorectal type simulate both metastatic colorectal carcinoma and primary ovarian endometrioid carcinomas. The appendiceal and ovarian tumors were immunophenotypically identical in each case. Approximately 50% of the appendiceal and ovarian tumors were positive for cytokeratin 7 (CK 7), and all were positive for cytokeratin 20 (CK 20). CK 20 positivity of the ovarian tumors is consistent with gastrointestinal origin; CK 7 positivity does not confirm ovarian origin, because appendiceal carcinomas are positive in 50% of cases. Metastatic appendiceal adenocarcinoma should be considered in the differential diagnosis of mucinous ovarian tumors with signet ring cell, goblet cell, or intestinal type differentiation, especially when these tumors are associated with extraovarian disease and are bilateral.

Disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis. A clinicopathologic analysis of 109 cases with emphasis on distinguishing pathologic features, site of origin, prognosis, and relationship to "pseudomyxoma peritonei".

Pseudomyxoma peritonei (PMP) is a poorly understood condition characterized by mucinous ascites and mucinous implants diffusely involving the peritoneal surfaces. There is considerable debate regarding the definition, pathology, site of origin, and prognosis of PMP. We analyzed the clinicopathologic features of 109 cases of multifocal peritoneal mucinous tumors to develop a pathologic definition of cases characterized by the clinical condition PMP. Cases were separated into two diagnostic categories: disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). Cases classified as DPAM were characterized by peritoneal lesions composed of abundant extracellular mucin containing scant simple to focally proliferative mucinous epithelium with little cytologic atypia or mitotic activity, with or without an associated appendiceal mucinous adenoma. Cases classified as PMCA were characterized by peritoneal lesions composed of more abundant mucinous epithelium with the architectural and cytologic features of carcinoma, with or without an associated primary mucinous adenocarcinoma. Sixty-five of the 109 cases (59.6%) were classified as DPAM consistent with origin from an appendiceal mucinous adenoma. Thirty-seven of the 65 cases (56.9%) had a documented appendiceal mucinous adenoma. Thirty cases (27.5%) were classified as PMCA consistent with origin from an appendiceal or intestinal mucinous adenocarcinoma. Fourteen cases (12.8%) were classified as PMCA with features intermediate between DPAM and PMCA or with discordant features based on the finding of at least focal areas of carcinoma in the peritoneal lesions, whether or not the primary site demonstrated carcinoma. The cases with intermediate features were derived from well-differentiated appendiceal or intestinal mucinous adenocarcinomas and had peritoneal lesions displaying features of DPAM as well as focal areas of mucinous carcinoma. The cases with discordant features were derived from atypical appendiceal adenomas with little or no histologic evidence of a transition from adenoma to carcinoma and had peritoneal lesions uniformly composed of mucinous carcinoma. There was a statistically significant difference in survival between cases classified as DPAM, those classified as PMCA with intermediate or discordant features, and those classified as PMCA (p < 0.0001). The age-adjusted 5-year survival rates were 84% for patients with DPAM, 37.6% for patients with PMCA with intermediate or discordant features, and 6.7% for patients with PMCA. The term DPAM should be used to diagnose the histologically benign peritoneal lesions associated with ruptured appendiceal mucinous adenomas and those that are pathologically identical but lack a demonstrable appendiceal adenoma. Cases with the pathologic features of adenocarcinoma should be designated PMCA because they have recognizably different pathologic features and a significantly worse prognosis.

Gastrointestinal cancer.

There are great differences in incidence and prognosis of cancer among the component sites of the digestive tract. Furthermore, a number of the histologic types of tumors at these sites differ in their incidence and prognosis. The SEER data from 1973 to 1987 on frequency, incidence, staging, and survival for the various histologic types of 194,452 cancers of the esophagus, stomach, and intestines were studied. There was an increased incidence of adenocarcinomas of esophagus, gastric cardia, small intestine, and colon; incidence rates for rectal adenocarcinoma and esophageal squamous cell carcinoma remained stable; and rates for gastric adenocarcinoma decreased. Blacks had higher incidence rates than whites for gastric adenocarcinoma; squamous cell carcinoma of the esophagus; carcinoids of the small intestine, colon, and rectum; and gastric sarcomas. Whites, especially males, had higher incidence rates for adenocarcinomas of the esophagus and gastric cardia than did blacks. Blacks had lower rates for rectal adenocarcinomas than did whites, but slightly higher rates than whites for rectal mucinous carcinomas and colonic adenocarcinomas. Data on race, sex, survival, and time trends indicate that mucinous colorectal carcinomas are biologically different from other adenocarcinomas. Males had poorer overall survival than did females for most histologic types of digestive tract tumors. Appendiceal mucinous adenocarcinomas with distant metastases were associated with a high (50%) 5-year survival. The poor prognosis of cases diagnosed as colonic carcinoid raises the possibility that some of these actually may be carcinomas. Studies of digestive tract cancer require analysis by histologic type for adequate assessment.

Tumors of the appendix: I. Neoplastic and nonneoplastic mucoceles.

We reviewed the clinical data and pathologic material on 46 patients with lesions originally interpreted as appendiceal mucocele or mucinous adenocarcinoma from two medical centers. The mucoceles, characterized by accumulation of mucus in a dilated lumen, could be divided into three distinct entities: nonneoplastic retention mucoceles (eight cases), cystadenomas (26 cases), and cystadenocarcinomas (eight cases). There were four mucinous adenocarcinomas. Retention mucoceles are associated with little morbidity and are cured by appendectomy. Cystadenomas and cystadenocarcinomas mimic the behavior of ovarian neoplasms of borderline malignant potential. Some of these lesions were associated with pseudomyxoma peritonei, but did not have systemic metastases. Mucinous adenocarcinomas without mucocele mimic the behavior of ordinary large bowel carcinoma.