Diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas by Fine Needle Aspiration Guided by Endoscopic Ultrasound and Histopathologic correlation: report of two cases

Introduction: Pseudopapillary solid malignancies are extremely rare and account for 0.17% –2.7% of all endocrine tumors of the pancreas, having a low grade malignancy and generally described in adolescents and young women; they are located mostly in the body and tail of the pancreas. Two cases of solid pseudopapillary neoplasm diagnosed by EUS-FNA (endoscopic ultrasound-fine needle aspiration) are described.

First case: Female patient of 18 years of age with clinic history of abdominal pain and increasing volume of abdominal girth. The CAT scan and the abdominal ultrasound reported an image in the tail of the pancreas. Endoscopic Ultrasound was performed using an electronic system SU-7000 of Fujinon® Corporation Japan, radial EG-530UR and a linear EG-530UT, which reported on the tail of the pancreas a well-defined lesion of 6×6cm with solid component and macrocysts delimited by septum with a central fibrous scar; lymph nodes were not reported and the pancreatic duct was not involved. A EUS-FNA with Wilson Cook Echotip® Ultra needle 22 gauges was conducted and two passes were made. Cytology reported solid pseudopapillary neoplasm. The patient went to surgical resection and surgical specimen confirmed the cytological diagnosis.

Second case: Female patient of 37 years of age with lumbar pain. The CAT scan reported mass occupying space in the body of the pancreas Endoscopic ultrasound was performed using an electronic system SU-7000 of Fujinon® Corporation Japan, radial EG-530UR and a linear EG-530UT, which reported a lesion in the in tail of the pancreas of 4×5cm., moderately defined, heterogeneous with few anechoic areas suggesting the existence of small cysts; the pancreatic duct was normal, no lymph nodes were reported and the splenic artery was involved. EUS-FNA with Wilson Cook Echotip® Ultra needle 25 gauges, was conducted, making 4 passes. Cytology reported solid pseudopapillary neoplasm, the patient went to surgical resection and distal pancreatectomy with splenectomy; the surgical specimen confirmed the cytological diagnosis.

Discussion: Solid Pseudopapillary Neoplasm of the Pancreas are rare with a low-grade malignancy that occurs mainly in young women; pain and abdominal mass are the most common symptoms but approximately 15% of the patients may be asymptomatic. In both cases, the patients were females and it called our attention the fact that one of them was out of the range reported in journals (37 ages); Uzquiano M. et al. describe a case of an SPS tumor in a female patient of 38 years of age. The size of solid pseudo papillary neoplasm is, generally, larger than 10cm. in diameter, in both cases, the lesions were between 4cm. and 6cm. in diameter. The ecoendoscopic findings of the first case highlight the cystic component in accordance with the generally described criteria in the journals for this type of lesion. In the second case, the solid component is mostly highlighted showing a scarse cystic component, without septum nor central fibrous scar.

These lesions, being extremely rare, are cataloged in our work unit; we had a frequency of two out of 798 cases reported and, in both these cases, the diagnosis was based on guided endoscopic ultrasound fine – needle aspiration; very few cases were found to have been diagnosed in this manner and confirmed by the surgical specimen (1, 2, 3, 4).