The SCN of the pancreas tends to be found as a large mass; however, such a large size with severe compression to surrounding organs seems to be rare . However, the present case showed a mass 20 cm in size with heavy weight in a small body-built female, and such an abdominal space-occupying case was not found in our search using Pubmed gov database (https://pubmed.ncbi.nlm.nih.gov/). Interestingly, she had experienced abdominal distension for 3 years; otherwise, no clinical symptoms were observed during this period. In this case, although radical resection could be expected by imaging analysis, a longer operating time and vascular injury to the retroperitoneal or intraabdominal main vasculature were anticipated with the usual anterior laparotomy approach. In cases of large and heavy abdominal tumors, lifting from the dorsal (retroperitoneal) side of the body can make it easier to operate and handle the dissection around the tumor, such as the liver hanging maneuver for a large liver cancer from the front of the vena cava , which has also been applied for distal pancreatectomy . Moreover, we often cooperate with urological surgeons for the resection of neoplasms originating from the retroperitoneal organs at our institute . Based on this experience, the prior observation, dissection, or transection of feeding vessels to the tumor via retroperitoneal laparoscopy or incision is very useful for defining the operative indication and subsequent procedures under additional laparotomy. As described above, the RetLap procedure seems useful for approaching the para-aortic lesion, and the confluence of the celiac axis, or SMA, can be easily dissected from the surrounding nerve plexus in the field of pancreatic surgery, particularly for DP-CAR under laparotomy . Although the concepts of RetLap and urological minimally invasive surgery are different, the combined concepts of this novel procedure for distal pancreatectomy and the conventional urological approach could be widely applied in the field of hepatobiliary–pancreas surgery. In this case, the installation area of the compressive part of the SCN on the retroperitoneal fascia or space was wide, and the tumor was expected to compress the surrounding area chronically for at least 3 years. Vascular injury to this area in a poor operating field is supposed to lead to a lethal situation; therefore, we expected to secure the dorsal space and confirm the possibility of safe dissection using the present approach. In fact, we thoroughly considered the effectiveness of a laparoscopic trial for retroperitoneal dissection in this case, and laparoscopy-assisted dissection was possible in the lateral position in retrospect. If we encounter a similar case, retroperitoneal dissection under laparoscopy would be attempted to find the tumor extension to the retroperitoneal organs and to minimize the length of the incision and its invasiveness for patients. Another advantage of this first retroperitoneal dissection was as follows: we did not care about serious injuries to important retroperitoneal organs or large vessels, and we could lift and mobilize this huge and heavy pancreatic tumor without any hesitation up to pancreatic transection. After this procedure, an additional laparotomy incision was required, except that unexpectedly massive bleeding or organ injury could be avoided, which was safer than the conventional anterior approach (Additional file 1).