Gastrointestinal stromal tumors and extra-gastrointestinal tract neoplasms.

OBJECTIVES: Gastrointestinal stromal tumor (GIST) is a relatively uncommon and predominantly sporadic tumor of the gastrointestinal tract (GIT). Infrequently, it can be associated with other neoplasms, notably GIT carcinomas and, rarely, extra-gastrointestinal tumors. Whether this concomitant occurrence is a causal association or a coincidence is not yet resolved, nor is its clinical importance determined. We attempted to investigate the frequency and spectrum of associations between non-incidental GISTs and extra-GIT tumors.
METHODS: A retrospective review study was carried out over 18 years of records. All confirmed cases of GISTs were retrieved from the pathology files of our institution. Each case was investigated for any synchronous or metachronous association with GIT or extra-GIT tumors.
RESULTS: Five (24%) out of 21 cases of GISTs were found to be either synchronously or metachronously associated with extra-gastrointestinal neoplasms in 55% of the women with GISTs. Males had no such association.
CONCLUSION: The cause of the association between non-incidental GISTs and extra-GIT tumors is difficult to determine. In the majority of cases, this association is most likely a coincidental finding. Synchronous occurrence with certain tumors, however, may suggest a nonrandom causal association. We report a case series study of the possible association of GISTs with extra-GIT tumors in female patients. Like other studies, we suggest that patients--especially women--with GISTs should be clinically investigated and followed up for the possibility of coexisting GIT and extra-GIT neoplasms.