Neuroendocrine (islet cell) tumor (NET) of the pancreas is a relatively rare pathologic condition.5
Most NETs of the pancreas are not associated with the clinical symptoms of hormonal over-secretion and are classified as nonfunctional.
Laparoscopic pancreatic surgery is emerging as a treatment option for nonfunctioning NETs of the pancreas. Based on our surgical experience with nonfunctioning NETs,11
53% of the patients had tumors in distal part of the pancreas and the median tumor size was 3.5 cm in diameter. Theoretically, laparoscopic distal pancreatectomy can be recommended for those neoplasms. However, in our experience, tumors greater than 3 cm in diameter were preoperative risk factors for an increased rate of metastasis and macroinvasion to adjacent organs, and substantially impacted patient survival. Therefore, the laparoscopic approach should be carefully chosen in large nonfunctioning NETs because curative resection is so important for long-term survival.
Laparoscopic distal pancreatectomy with or without splenectomy has been reported in the literature as a treatment for nonfunctioning NETs of the pancreas,1,5,12
but reports of laparoscopic enucleation of nonfunctioning NETs of the pancreas are rare. This relative paucity of data may be related to the asymptomatic nature of these neoplasms. In contrast, laparoscopic enucleation of functioning NETs, such as insulinomas, has been frequently described. The asymptomatic nature of small nonfunctioning NETs is an obstacle to the early discovery of such tumors. However, the frequency of early detection of small lesions in the pancreas is expected to increase due to easy accessibility of abdominal ultrasound and increased patient health awareness. With such early detection, laparoscopic enucleation of small, nonfunctioning NETs of the pancreas could offer a shorter hospital stay, good cosmetic effect, less pain, and an early return to normal social activity.
Only two cases of laparoscopic enucleation for nonfunctioning pancreatic NETs have been reported in the literature ().13,14
In general, nonfunctioning NETs in the pancreatic head are not recommended for such surgery because of the risk of open conversion due to technical difficulties or an inability to localize the tumor.15
However, successful laparoscopic enucleation of such tumors has been reported, and this procedure appears to be feasible and reproducible in well-selected benign nonfunctioning NENs of the pancreas.
Literature Review of Nonfunctioning Neuroendocrine Tumors of the Pancreas Treated by Laparoscopic Enucleation
Minimally invasive surgery is thought to both reduce surgical damage and minimize the frequency of postoperative complications. Enucleation procedures have the advantage of preserving pancreatic and spleen parenchyma, without the morbidity, mortality, or late sequelae of extensive resection.16
The most common complication is pancreatic fistula.17
Accordingly, patients may be considered candidates for enucleation if the pancreatic neoplasm is free of the pancreatic duct and has no vascular involvement on preoperative imaging studies. To this end, intraoperative ultrasound can aid in identifying the mass and determining its proximity to the pancreatic duct, which can decrease the incidence of the pancreatic fistula.18
In current case, we did not place any type of drain system because the tumor was very small (about 1 cm) and superficial location apart from main pancreatic duct, which may have low risk of postoperative pancreatic fistula. We don't think any drainage sysment is necessary.
In summary, we avoided a long abdominal incision and inflicted less stressful surgical damage by laparoscopically treating the small, nonfunctioning NET of this older patient. Laparoscopic enucleation of well-selected non-functioning NETs of the pancreas, such as a single, small, benign pancreatic mass superficially located in the pancreas, seems to be feasible. However, long-term follow up is mandatory given their likelihood of a more malignant course.