Unusual case of PNET in the abdomen
By Dr. Praveen Kammar
Brief History: We recently consulted a 42 year old male patient who was diagnosed with a large PNET in the retoperitoneum stretching out the bifurcation of the coeliac artery, superior mesentric artery (SMA), involving the distal pancreas, DJ flexure and splenic vessels.
Patient had received induction chemotherapy and had undergone an exploratory laparotomy where it was considered to be inoperable. The patient had then received 6 months of palliative chemotherapy. At evaluation, the disease was still localized with stable findings on CT scan and no e/o disease elsewhere on the PET scan.
After a careful assessment, we decided to go for a exploratory laparotomy with the intention of resecting the tumour with negative margins.
Since the disease was previously declared inoperable, patient was apprehensive to explore surgical options. He was worried if a good surgery with complete removal of the tumor was possible.
We had previewed a distal pancreatosplenectomy with resection of DJ flexure with possible vascular reconstruction of the superior mesenteric artery and/or vein. At surgery, the lesion was involving the DJ flexure, pancreas at the neck and body, splenic vessels and abutting and splaying the SMA and coeliac axis without infiltration of the structures.(fig01)
A complete resection was performed with distal pancreatosplenectomy, wedge resection of DJ flexure. (fig 2,3 & 4)
Fig 01. PNET involving the DJ flexure, pancreas at the neck and body, splenic vessels and abutting and splaying the SMA and coeliac axis without infiltration of the structures.(fig01)
Post operative course was uneventful and patient was discharged at 7 days.
Primitive Neuroectodermal Tumour (PNET, also referred to as Ewing’s sarcoma) rarely occurs in the soft tissue and even rarer is a presentation within the abdominal cavity. Usually they reach very large size before they become symptomatic, especially in the abdomen.
Due to the close proximity to several vital structures in the abdomen, PNETs can spread to surrounding organs and blood vessels. However, with careful assessment of CT scans and meticulous planning, tumors sitting in critical areas ,and appearing inoperable to untrained eyes, can be removed completely with minimal adverse effects.