title: A solid pseudopapillary neoplasm without cysts that occurred in a patient diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a case report.
abstract: BACKGROUND
  Solid pseudopapillary neoplasm of the pancreas is a rare neoplasm that has been reported to account for between 0.17% and 2.7% of all non-endocrine tumors of the pancreas. It is usually seen in young women. Because solid pseudopapillary neoplasms are rarely aggressive and have low-grade malignant potential and an excellent prognosis after complete resection, it is an ideal pancreatic tumor for treatment by minimally invasive surgery. Therefore, making an accurate pre-operative diagnosis is very important.
  
  
  METHODS
  A 24-year-old Japanese man who had been found to have mild transaminase elevations at a medical check-up visited our hospital for further examination. Abdominal computed tomography showed a 40mm-diameter tumor in the pancreatic tail and mild fatty liver. He was admitted to our hospital for additional examination. The abdominal contrast-enhanced computed tomography scan taken at our institution showed an increasingly enhanced mass of 40mm diameter in the pancreatic tail. Ultrasonography showed a low-level echoic mass of 35mm diameter in the pancreatic tail. T1-weighted magnetic resonance imaging showed low signal intensity in the tail of the pancreas. T2-weighted magnetic resonance imaging showed high signal intensity there. Diffusion magnetic resonance imaging showed high signal intensity. An endoscopic ultrasound yielded the same results as the abdominal ultrasonogram. In addition, [18F]-fluorodeoxyglucose positron emission tomography/computed tomography showed abnormal accumulation (maximum standardized uptake value, 6.53). This finding raised our suspicion of a pancreatic malignant tumor. However, the patient could not be confidently diagnosed solely on the basis of imaging. Endoscopic ultrasound-guided fine-needle aspiration was performed, which led us to a diagnosis of solid pseudopapillary neoplasm. On that basis, we performed minimally invasive surgery (spleen-preserving laparoscopic distal pancreatectomy).
  
  
  CONCLUSIONS
  Atypical solid pseudopapillary neoplasm without cysts should be considered when diagnosing pancreatic tumors. A definitive pre-operative diagnosis of solid pseudopapillary neoplasm made on the basis of endoscopic ultrasound-guided fine-needle aspiration can guide the surgical approach used.
authors.affiliation: Department of Internal Medicine, Okayama Saiseikai General Hospital, 1-17-18 Ifuku-cho, Okayama 700-8511, Japan. sktng334@yahoo.co.jp.
authors.forename: Masakuni
authors.initials: M
authors.lastname: Fujii
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshioka
authors.forename: Takefumi
authors.initials: T
authors.lastname: Niguma
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Saito
authors.forename: Toru
authors.initials: T
authors.lastname: Kojima
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nose
authors.forename: Junji
authors.initials: J
authors.lastname: Shiode
mesh_terms: D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D006801:Humans; D008297:Male; D064847:Multimodal Imaging; D009375:Neoplasms, Glandular and Epithelial / Q000175:diagnosis* / Q000601:surgery; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D055815:Young Adult