We present the case of a 63-y.o. Caucasian female patient presenting to our hospital with a distal pancreatic mass, found on a CT scan of the abdomen. The patient’s medical history reveals a hysterectomy and bilateral adnexectomy, with appendectomy due to an ovarian mass, approximately 5 years prior to the consultation in our clinic. Before the hysterectomy, her CA19-9 levels were elevated at 376 U/ml. After the initial surgery, she underwent chemotherapy with carboplatin 480mg, with regular follow-ups. For 3 years she didn’t have any symptoms or abnormal results, until her CA 125 was increased at 82.9 U/ml. This prompted an MRI and CT scans which showed a thickening of the wall of the stomach. A gastroscopy with a biopsy was done, and a histology consistent with a B-cell Lymphoma was obtained. She was treated by a hematologist, and remained symptom free ever since, although her CA125 levels remained slightly elevated, ranging between 51 and 86 U/ml. Approximately 4.5 years after the surgery, her CA19-9 levels were detected to be elevated at 54.39 U/ml, even though they have been normal ever since the first surgery. This was the reason to obtain another CT scan, which showed a distal pancreatic mass (Fig. 1).
A PET scan was ordered in order to differentiate the lesion and detect any additional lesions. The result of the PET scan showed a metabolically active lesion in the distal pancreas and in the splenic hilum. (Fig. 2)
Given the above results, an extirpation of the tumor was indicated. Considering its location within the splenic hilum, the procedure of choice was determined to be a distal pancreatectomy with splenectomy. To enhance the precision of the surgical approach, a decision was made to construct a 1:1 replica of the patient’s organs to be used for preoperative planning. Using an open-source software the 3D model was generated from the CT scan data, which was obtained with a slice thickness of 1.25mm during the arterial contrast phase. Previous research shows that models generated through such methods offer an exceptionally accurate representation of the anatomical structures, with a margin of error measuring less than 1% [8].
The model of the patient’s anatomy was printed using a Fused Deposition Modeling (FDM) printer, with Thermoplastic Polyurethane (TPU) selected as the material of choice. (Fig. 3) The files were printed with 2 wall thickness, as only one would tear, with lightning infill which allowed the majority of the organ to be empty, but still have sufficient support for the structure to not collapse on it self. TPU was chosen because of its flexibility which enabled us to systematically deconstruct the model into its constituent components. This deconstruction facilitated a comprehensive examination of each element in isolation, and we were able to subsequently assemble the model to precisely replicate the in situ anatomical configuration of the patient.
The surgical team was given ample time to analyze the 3D printed model and to devise an operative plan. Once the surgery has been completed, the specimen shown in the image below (Fig. 4) was obtained and a side-to-side comparison of the printed model and the obtained specimen was made, further strengthening the notion that the 3D printed model was an accurate representation of the patient’s anatomy. The operation was done in 90 minutes, which is a relatively short time for a distal pancreatectomy with splenectomy [9]. The 3D printed model continued to serve as an invaluable visual reference intraoperatively, offering real-time guidance and enhancing the surgical team's spatial awareness.The surgical team was under the impression that being able to prepare and plan the operation using the 3D printed model was of immense help.
The patient’s recovery after the procedure went as expected, no SSI were noted, the abdominal drain was removed on postoperative day 5 and she was discharged on postoperative day 9.
The histological analysis of the specimen showed a coagulative necrosis of the splenic tissue (Fig. 5a).
The analysis of the lesion showed pancreatic tissue bordering a pseudocystic formation encased in a pseudocapsule of connective tissue with an intraluminal neoplastic proliferation of epithelial cells which have a cubic-polygonal shape and pleomorphism. The nuclei are round to oval with a varying degree of eosinophilic cytoplasm, with some mythoses visible. The cells are arranged in cystic and papilliform fashion. The following phenotype was performed: CA125+, WT1, ER+, Pax8 +, PR -, CA19/9 - (Fig. 5b)
The discovered findings exhibit distinctive characteristics that align with a rare pancreatic neoplasm, manifesting indications suggestive of papillary serous pancreatic cystadenocarcinoma. However, the diagnostic approach is further nuanced by considerations of the immunophenotype, raising the plausible inference that these manifestations may represent a distant metastasis stemming from the patient's prior ovarian cystadenocarcinoma. The differential diagnosis, informed by both histological features and immunohistochemical markers, underscores the complexity in accurately categorizing the nature of the pancreatic lesion.