Collision tumour involving a rectal gastrointestinal stromal tumour with invasion of the prostate and a prostatic adenocarcinoma

Abstract

BackgroundGastrointestinal stromal tumours (GISTs) are the most common primary mesenchymal neoplasia in the gastrointestinal tract, although they represent only a small fraction of total gastrointestinal malignancies in adults (<2%). GISTs can be located at any level of the gastrointestinal tract; the stomach is the most common location (60-70%), in contrast to the rectum, which is most rare (4%). When a GIST invades into the adjacent prostate tissue, it can simulate prostate cancer. In this study, we report on a case comprising the unexpected collision between a rectal GIST tumour and a prostatic adenocarcinoma.FindingsWe describe the complexity of the clinical, endoscopic and radiological diagnosis, of the differential diagnosis based on tumour biopsy, and of the role of neoadjuvant therapy using imatinib prior to surgical treatment.ConclusionsAlthough isolated cases of coexisting GISTs and prostatic adenocarcinomas have previously been described, this is the first reported case in the medical literature of a collision tumour involving a rectal GIST and prostatic adenocarcinoma components.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1238437468776331.

Rectal gastrointestinal stromal tumor with metastasis to the penis: Case report and review of literature

“…Clinical characteristics of the tumor are dependent on the anatomic location, size, and aggressiveness of the tumor. Primary GISTs originate most commonly in the stomach [2], but primary GISTs arising from the pleura, retroperitoneum, omentum, and mesentery have also been reported [3]. GISTs typically metastasize to intra-abdominal locations, with common metastatic sites being the liver, omentum, and the peritoneal cavity [4].…”

Subsequent intra-abdominal fibromatosis mimicking recurrent gastrointestinal stromal tumor

“…With the accumulation of knowledges on GIST and long-time follow-up information, GIST patients are found to simultaneously or metachronously have other types of tumors [2-7], some of which are easier to be differentiated from GIST [4,6], while others might be confused with recurrent GIST from the clinical point of view [2,3]. …”

Gastrointestinal stromal tumour with an unusual presentation as a huge prostatic mass: a case report

“…GISTs are the most frequently diagnosed primary mesenchymal tumour in the gastrointestinal tract. Nevertheless, GISTs are rare diseases, only accounting for a small percentage (<2%) of the total gastrointestinal malignant tumours in the population . EGISTs are commonly derived from the mesentery, omentum and retroperitoneum, which only account for 5–10% of GISTs .…”

“…Histopathology is the gold standard in GIST diagnosis. Prostatic GIST is diagnosed based on cell morphology, and positive immunostaining for CD117, DOG1 and CD34 . CD34 is not a GIST‐specific marker.…”

“…Nevertheless, GISTs are rare diseases, only accounting for a small percentage (<2%) of the total gastrointestinal malignant tumours in the population. 1 EGISTs are commonly derived from the mesentery, omentum and retroperitoneum, which only account for 5-10% of GISTs. 2,3 Nevertheless, it has also been reported that EGISTs have also been observed in other sites, including pancreas, urinary bladder, seminal vesicles and female genital organs.…”