Role of endoscopic ultrasound in the characterization of solid pseudopapillary neoplasm of the pancreas

BACKGROUND Solid pseudopapillary neoplasm(SPN)is an uncommon pathology of the pancreas with unpredictable malignant potential.Endoscopic ultrasound(EUS)assessment plays a vital role in lesion characterization and confirmation of the tissue diagnosis.However,there is a paucity of data regarding the imaging assessment of these lesions.AIM To determine the characteristic EUS features of SPN and define its role in preoperative assessment.METHODS This was an international,multicenter,retrospective,observational study of prospective cohorts from 7 large hepatopancreaticobiliary centers.All cases with postoperative histology of SPN were included in the study.Data collected included clinical,biochemical,histological and EUS characteristics.RESULTS One hundred and six patients with the diagnosis of SPN were included.The mean age was 26 years(range 9 to 70 years),with female predominance(89.6%).The most frequent clinical presentation was abdominal pain(80/106;75.5%).The mean diameter of the lesion was 53.7 mm(range 15 to 130 mm),with the slight predominant location in the head of the pancreas(44/106;41.5%).The majority of lesions presented with solid imaging features(59/106;55.7%)although 33.0%(35/106)had mixed solid/cystic characteristics and 11.3%(12/106)had cystic morphology.Calcification was observed in only 4(3.8%)cases.Main pancreatic duct dilation was uncommon,evident in only 2 cases(1.9%),whilst common bile duct dilation was observed in 5(11.3%)cases.One patient demonstrated a double duct sign at presentation.Elastography and Doppler evaluation demonstrated inconsistent appearances with no emergence of a predictable pattern.EUS guided biopsy was performed using three different types of needles:Fine needle aspiration(67/106;63.2%),fine needle biopsy(37/106;34.9%),and Sonar Trucut(2/106;1.9%).The diagnosis was conclusive in 103(97.2%)cases.Ninety-seven patients were treated surgically(91.5%)and the post-surgical SPN diagnosis was confirmed in all cases.During the 2-year follow-up period,no recurrence was observed.CONCLUSION SPN presented primarily as a solid lesion on endosonographic assessment.The lesion tended to be located in the head or body of the pancreas.There was no consistent characteristic pattern apparent on either elastography or Doppler assessment.Similarly SPN did not frequently cause stricture of the pancreatic duct or common bile duct.Importantly,we confirmed that EUS-guided biopsy was an efficient and safe diagnostic tool.The needle type used does not appear to have a significant impact on the diagnostic yield.Overall SPN remains a challenging diagnosis based on EUS imaging with no pathognomonic features.EUS guided biopsy remains the gold standard in establishing the diagnosis.

Cheesy material on macroscopic on-site evaluation after endoscopic ultrasound-guided fine-needle biopsy:Don't miss the tuberculosis

Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.