Endoscopic Ultrasound Guided Fine Needle Aspiration of the Pancreas

EUS-FNA, ancillary studies and their clinical utility in patients with mediastinal, pancreatic, and other abdominal lesions

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an important modality to obtain tissue diagnosis from mediastinal, pancreatic, and intra-abdominal lesions in close proximity to the pulmonary and gastrointestinal tract. It is considered to be a relatively safe, rapid, and minimally invasive technique with low complication rates.

AIMS

To determine the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and outcome of EUS-FNA, with histological correlation where applicable.

METHODS

Data of all 1059 consecutive patients who underwent EUS-FNA from 1 January 2005 to 31 December 2017 at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore was reviewed in this retrospective study. The major sites that were targeted for EUS-FNA were pancreatic (423), mediastinal (376), and other abdominal lesions (260).

RESULTS

The average number of passes per patient was 2.22. Rapid on-site evaluation (ROSE) was adequate in 969 patients (91.4%). Concordance between ROSE and final cytology was 99.5%. Follow-up was available in 810 patients (76.4%). The overall diagnostic yield was 94.3%. Ancillary studies, including immunohistochemical stains and flow cytometry, helped to increase the diagnostic yield from 78.1% to 94.3%. The overall sensitivity, specificity, PPV, NPV, and diagnostic accuracy for EUS-FNA were 94.8%, 98.6%, 99.9%, 65.5%, and 95.1%, respectively. Seven of 1059 patients (0.6%) developed complications.

CONCLUSION

EUS-FNA is a very sensitive and specific diagnostic tool with a minimal complication rate. Ancillary studies helped to increase the sensitivity, as well as the diagnostic yield.

Cercariform cells: another cytologic feature distinguishing solid pseudopapillary neoplasms from pancreatic endocrine neoplasms and acinar cell carcinomas in endoscopic ultrasound-guided fine-needle aspirates

BACKGROUND

Solid pseudopapillary neoplasm (SPPN) is a rare tumor of unknown origin that occurs predominantly in the body or tail of the pancreas in young women. The authors recently identified cercariform (Greek: tailed) cells, similar to those described in urothelial carcinomas, as a consistent cytologic feature in ultrasound-guided fine-needle aspiration (EUS-FNA) samples from SPPNs. The objective of the current multi-institutional study was to define the value of these cells in the differential diagnosis of SPPN with other neoplasms characterized cytologically by the presence of monotonous, uniform cells in pancreatic aspirates: pancreatic neuroendocrine tumors (Pan-NETs) and acinar cell carcinomas (ACCs).

METHODS

The files of 4 academic hospitals were searched for SPPNs, Pan-NETs, and ACCs that were diagnosed by EUS-FNA. The slides were reviewed, and several cytologic features were recorded semiquantitatively to identify discriminating features between SPPNs, Pan-NETs, and ACCs.

RESULTS

From the analysis of 18 SPPNs, 4 ACCs, and 20 Pan-NETs, the following cytologic features were identified as common to all 3 neoplasms: single cells and rosettes/acinar cell groups, round-to-plasmacytoid cells, pale-to-granular cytoplasm, fine vacuoles, and binucleated cells. Papillary structures, cercariform cells, large cytoplasmic vacuoles, reniform nuclei, hyaline globules/magenta-colored material, and degenerative features (cholesterol crystals, calcifications, foam cells, or giant cells) were significantly more common in SPPNs. Prominent nuclear grooves were encountered in only 4 of 18 SPPNs.

CONCLUSIONS

The current results indicated that the presence of cercariform cells is another useful clue for the cytologic diagnosis of SPPN in challenging cases.

Diagnostic usefulness and challenges in the diagnosis of mesothelioma by endoscopic ultrasound guided fine needle aspiration

Malignant mesothelioma is a rare neoplasm. It has been noted in the literature that fine needle aspiration (FNA) is a useful tool for the diagnosis of mesothelioma. However, the differential diagnosis may require use of a battery of immunohistochemical stains. Clinico-radiologic correlation is also crucial. Real time endoscopic ultrasound (EUS) combined with FNA has been shown to be a very sensitive technique to obtain samples from different organ sites, including mediastinal lesions. The use of EUS-FNA for the diagnosis of mesothelioma, reinforces the role of a cytopathologist as a cohesive team player along with a radiologist and a clinician during on-site assessment for the proper triage of additional specimens for ancillary studies leading to a better patient management.

Endoscopic ultrasound guided fine needle aspiration of non-pancreatic lesions: an institutional experience

BACKGROUND

Endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) has proven to be an effective diagnostic modality for the detection and staging of pancreatic malignancies. In recent years EUS-FNA has also been used to diagnose lesions of non-pancreatic sites such as structures in close proximity to the gut wall within the mediastinum, abdomen, pelvis and retro-peritoneum.

AIMS

To evaluate experience with EUS-FNA of non-pancreatic sites at a large university medical centre.

METHODS

The study cohort included 234 patients who underwent EUS-FNA of 246 lesions in non-pancreatic sites (122 peri-pancreatic and coeliac lymph nodes; 9 peri-pancreatic masses; other sites: mediastinum 12, gastric 25, liver 27, oesophagus 17, duodenum/colon/rectum 15, retro-peritoneum 8, lung 7, miscellaneous 4).

RESULTS

The cytology diagnoses were classified as non-neoplastic/reactive in 82 (33%), atypical/suspicious for malignancy in 25 (10%), malignant in 86 (35%) and non-diagnostic in 53 (22%) cases. Surgical pathology follow-up was available in 75 (31%) cases. Excluding the non-diagnostic cases there were 7 false negative and 3 false positive cases. The sensitivity, specificity and positive predictive value of EUS-FNA in the diagnosis of lesions of non-pancreatic sites was 92%, 98% and 97%, respectively.

CONCLUSIONS

EUS-FNA can be effectively used as a diagnostic modality in the diagnosis of lesions from non-pancreatic sites.

Biomarkers in Diagnosis of pancreatic carcinoma in fine-needle aspirates

This study was undertaken to determine whether recently identified proteins could be translated to clinical practice as markers to distinguish pancreatic adenocarcinoma from chronic pancreatitis on fine-needle aspirate (FNA) samples. Resected pancreatic tissue sections (n = 40) and FNA samples (n = 65) were stained for clusterin-beta, MUC4, survivin, and mesothelin. For each biomarker, the staining patterns in adenocarcinoma and in reactive ductal epithelium were evaluated and compared. Clusterin-beta stained reactive ductal epithelium significantly more frequently than pancreatic adenocarcinoma (P < .001). In comparison, MUC4 and mesothelin were expressed more frequently in pancreatic adenocarcinoma on tissue sections. Positive staining for MUC4 (91% vs 0%; P < .001) and mesothelin (62% vs 0%; P = .01) and absence of staining for clusterin-beta (90% vs 7%; P < .001) were noted significantly more frequently in adenocarcinoma cells than in reactive cells in FNA samples. Clusterin-beta and MUC4 can help distinguish reactive ductal epithelial cells from the cells of pancreatic adenocarcinoma in FNA samples.