Collision Tumors of the Gastrointestinal Tract: A Systematic Review of the Literature.

BACKGROUND/AIM: Collision tumors are rare neoplasms which consist of two or more distinct neoplasms that develop adjacent to one another and coexist with no or minimal intermingling between them. Their diagnosis is often incidental and their behavior remains widely unknown. Several theories have been proposed regarding their pathogenesis. The objective of this study was the evaluation of current evidence on collision tumors of the gastrointestinal tract regarding their pathology, biological behavior and treatment approach. MATERIALS AND METHODS: The PubMed and Cochrane bibliographical databases were searched from January 1997 to July 2018 (last search: July 5th, 2018) for studies reporting on collision tumors of the gastrointestinal tract that also included a therapeutic approach. RESULTS: Forty-seven studies reporting on collision tumors of the gastrointestinal tract were identified. They reported collectively on 53 cases (43 males, 10 females) with collision tumors of the esophagus, stomach, small intestine and large intestine. The vast majority (96.2%) of tumors consisted of two distinct histological components and only two cases involved a greater number of histological subtypes. Fifty-one patients underwent a surgical or endoscopic tumor resection, accompanied in 22 cases by adjuvant or neoadjuvant therapy. The remaining two patients underwent palliative operations. In total, three patients experienced immediate postoperative complications. CONCLUSION: Collision tumors of the gastrointestinal tract, despite their rare nature, constitute a quite interesting field of study. This review offers a thorough insight into the clinicopathological characteristics and biological behavior of these rare tumors.

A new pancreaticojejunostomy technique: a battle against postoperative pancreatic fistula.

AIM: To present a new technique of end-to-side, duct-to-mucosa pancreaticojejunostomy with seromuscular jejunal flap formation, and insertion of a silicone stent. METHODS: We present an end-to-side, duct-to-mucosa pancreaticojejunostomy with seromuscular jejunal flap formation, and the insertion of a silicone stent. This technique was performed in thirty-two consecutive patients who underwent a pancreaticoduodenectomy procedure by the same surgical team, from January 2005 to March 2011. The surgical procedure performed in all cases was classic pancreaticoduodenectomy, without preservation of the pylorus. The diagnosis of pancreatic leakage was defined as a drain output of any measurable volume of fluid on or after postoperative day 3 with an amylase concentration greater than three times the serum amylase activity. RESULTS: There were 32 patients who underwent end-to-side, duct-to-mucosa pancreaticojejunostomy with seromuscular jejunal flap formation. Thirteen of them were women and 19 were men. These data correspond to 40.6% and 59.4%, respectively. The mean age was 64.2 years, ranging from 55 to 82 years. The mean operative time was 310.2 ± 40.0 min, and was defined as the time period from the intubation up to the extubation of the patient. Also, the mean time needed to perform the pancreaticojejunostomy was 22.7 min, ranging from 18 to 25 min. Postoperatively, one patient developed a low output pancreatic fistula, three patients developed surgical site infection, and one patient developed pneumonia. The rate of overall morbidity was 15.6%. There was no 30-d postoperative mortality. CONCLUSION: This modification appears to be a significantly safe approach to the pancreaticojejunostomy without adversely affecting operative time.