title: Gastrointestinal stromal tumor with autonomic nerve differentiation and coexistent mantle cell lymphoma involving the appendix.
abstract: Gastrointestinal stromal tumor (GIST) and mantle cell lymphoma involving the appendix are rare as individual disease entities. Their coexistence has not been previously reported in the literature. We describe a 65-year old female who presented with extensive ileocecal mantle cell lymphoma, which extended to the appendix. The appendix was involved by mantle cell lymphoma and an incidental coexistent GIST was noted in the appendiceal wall. The GIST was CD117 positive but did not harbor mutations in the c-kit and PDGFR genes. In addition, it was unusual in showing S-100 immunoreactivity and ultrastructural evidence of autonomic nerve differentiation. This is the first description of the association of a GIST with autonomic nerve differentiation coexisting with mantle cell lymphoma in the appendix.
authors.affiliation: Departments of Pathology, The Jewish General Hospital, Montreal and University Health Network, University of Toronto Toronto, Canada.
authors.forename: Kurosh
authors.initials: K
authors.lastname: Rahimi
authors.forename: Adrian
authors.initials: A
authors.lastname: Gologan
authors.forename: Tina
authors.initials: T
authors.lastname: Haliotis
authors.forename: Esther
authors.initials: E
authors.lastname: Lamoureux
authors.forename: Runjan
authors.initials: R
authors.lastname: Chetty