Endoscopic ultrasound-guided fine-needle aspiration. A cytopathologist's perspective

Endoscopic ultrasound-guided fine-needle aspiration cytology of pancreatic neuroendocrine tumors: a study of 48 cases

BACKGROUND

Neuroendocrine tumors (NETs) of the pancreas are relatively uncommon tumors. The objective of this report was to describe the cytopathologic and immunocytochemical features of NETs obtained by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA).

METHODS

Forty-eight patients who were diagnosed with pancreatic NETs based on EUS-guided FNA were studied retrospectively (from 2002 to 2007). Clinical data, EUS findings, cytopathologic features, and immunocytochemical stains were reviewed for this study. The final histopathologic diagnosis from each patient also was available for comparison.

RESULTS

Forty-eight patients (28 men and 20 women) who ranged in age from 16 years to 86 years were selected and had the following clinical findings: solid or multiple pancreatic masses diagnosed by computed tomography or magnetic resonance imaging studies; simultaneous, suspicious, metastatic masses in the liver, mediastinum, and/or lung; hypoglycemia; multiple endocrine neoplasia type 1 syndrome; von Hippel-Lindau syndrome; and primary NET of the small bowel. EUS findings revealed solid or multiple masses in the pancreatic head/uncinate, or in the pancreatic body/tail, or simultaneously in the pancreatic head/uncinate and body/tail. Cytologically, 40 patients were diagnosed with NETs (histopathogically confirmed), and 8 patients had findings that were suspicious of NETs (2 patients had false-positive results, and 6 patients had histopathologically confirmed NETs). The most helpful cytologic findings for the diagnosis of NET were a richly cellular sample with a monotonous, poorly cohesive population of small or medium-sized cells with granular chromatin (salt and pepper) and plasmacytoid morphology. Immunocytochemistry confirmed the neuroendocrine origin of tumors in 40 patients (material for immunocytochemistry was inadequate in 8 patients).

CONCLUSIONS

The current results indicated that EUS-guided FNA is a useful method for the diagnosis of pancreatic NETs. Cytopathologic examination in coordination with immunocytochemistry can provide an accurate diagnosis in most patients.

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.

Distinguishing benign dissecting mucin (stromal mucin pools) from invasive mucinous carcinoma

Mucin dissecting stroma suggests the presence of an invasive mucinous (colloid) carcinoma. However, in virtually every organ in which invasive mucinous carcinoma exists, there exist benign mimickers associated with dissecting mucin. This article reviews diagnostic criteria for the differential diagnosis of mucinous lesions of the breast, pancreas, biliary tract, colon, appendix, and bladder, emphasizing practical points, which we find helpful in daily diagnostic surgical pathology practice.

Endoscopic ultrasound-guided fine-needle aspiration: sampling, pitfalls, and quality management

Endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) is an accurate and versatile technique in the diagnosis of gastrointestinal tract lesions as well as other organ sites. EUS FNA is performed ideally with cytopathologic adequacy evaluation, and diagnosis at the time of tissue procurement. In this article, we review the most relevant issues in the process of EUS FNA-based diagnostics. Specifically, we describe the technical aspects of specimen collection, processing, and appropriate selection of ancillary studies. We also illustrate the most commonly encountered diagnostic pitfalls, and methods for their avoidance. Lastly, we discuss quality management, which emphasizes the communication between the endoscopist and the pathologist.

Providing on-site diagnosis of malignancy on endoscopic-ultrasound-guided fine-needle aspirates: should it be done?

BACKGROUND

Rapid and accurate tissue diagnosis for a deep-seated malignancy would allow treating physicians to provide disease-specific interventions and help patients make early informed management decisions. Providing on-site tissue diagnosis for fine-needle aspirate samples obtained with endosonography would help develop such efficient patient management issues. Here we report our experience of prospectively providing on-site diagnosis on 485 endoscopic ultrasound fine-needle aspirate samples.

METHODS

Four hundred eighty-five endoscopic ultrasound fine-needle aspirates from the pancreas (n= 305), lymph nodes (n = 91), biliary tree (n = 47), liver (n = 15), gastrointestinal tract (n = 19), and adrenal gland (n = 8) were reviewed. For all aspirates, the cytologic diagnoses, both preliminary and final, were categorized into the following: positive for malignancy, positive for neoplastic process, suspicious for malignancy, atypical cells, reactive process, and nondiagnostic.

RESULTS

Of the 485 cases, 163 (33.6%) were diagnosed as benign, 43 (8.8%) as atypical, 21 (4.3%) as suspicious, 18 (3.7%) as positive for neoplasm, and 230 (47.4%) as malignant after final cytologic interpretation. A significantly (P < .001) higher degree of concordance was noted for unequivocal diagnosis of malignancy (196/198, 98.9%) vs nonmalignancy (200/250, 67.2%) between on-site and final cytologic diagnosis. Of the 52 discordant cases, 12 (2.6%) diagnoses were downgraded and 40 (8.9%) were upgraded from preliminary on-site diagnosis. Our overall sensitivity (87 vs 92), specificity (95% vs 100%), and accuracy (90% vs 94%) improved for final cytologic diagnosis.

CONCLUSION

On-site diagnosis of malignancy could be used to initiate informed patient management decisions. Cases where a diagnosis of malignancy is not rendered at on-site interpretation need further cytologic evaluation.

Endoscopic ultrasound-guided fine-needle aspiration and Trucut biopsy in thoracic lesions: when tissue is the issue

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) has a high accuracy in the evaluation of mediastinal lesions. The use of a core biopsy needle for EUS guided biopsy (EUS TCB) may further improve the yield of EUS. The aims of this study are to evaluate the safety of EUS TCB in thoracic lesions and to compare the diagnostic accuracy of TCB with FNA and FNA + TCB.

METHODS

A single-center retrospective study. All patients underwent EUS-FNA and TCB. A cytopathologist was not present during the procedure. EUS FNA, TCB and FNA + TCB diagnostic accuracy were compared.

RESULTS

A total of 48 patients were included. The lesions sampled included 41 lymph nodes (six aorto-pulmonary window, 32 subcarinal, two right paratracheal, one paraesophageal ATS station 8), five lung masses, and two esophageal masses. Twenty-nine patients had malignant disease and 19 had benign disorders. The overall diagnostic accuracy of FNA, TCB and FNA + TCB was 79%, 79% and 98% respectively (p = 0.007). TCB changed the diagnosis in nine cases missed by FNA. EUS TCB was better than FNA for benign diseases (89% vs. 63%, p = 0.04). All eight patients with a prior failed biopsy had a correct diagnosis established by EUS. No patient required mediastinoscopy or thoracoscopy after EUS.

CONCLUSION

The combination of TCB and FNA is superior to FNA alone. EUS-guided TCB should be considered in patients with benign disorders of the mediastinum when other modalities fail to yield a diagnosis.

Precursor lesions of pancreatic cancer: molecular pathology and clinical implications

BACKGROUND

Pancreatic cancer is a lethal disease, with near uniform 5-year mortality rates. The key to improving survival of pancreatic cancer rests upon early detection of this neoplasm at a resectable, and hence potentially curable, stage.

METHODS

We review the current state of the literature vis-à-vis the three common precursor lesions of pancreatic adenocarcinoma: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. We also discuss two clinical scenarios of emerging importance, namely asymptomatic pancreatic cysts ('pancreatic incidentalomas') and the significance of precursor lesions in familial pancreatic cancer kindreds.

RESULTS

Pancreatic intraepithelial neoplasias are the microscopic precursor lesions of pancreatic adenocarcinomas, while intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are macroscopic, cystic precursor lesions. All three noninvasive entities demonstrate a multistep morphologic and genetic progression that culminates in frank invasive adenocarcinoma. Despite these commonalities, each precursor lesion harbors a unique repertoire of clinicopathologic and genetic characteristics that has an impact on natural history and prognosis of these lesions. Due to improvements in radiological techniques, asymptomatic pancreatic cysts are being increasingly discovered in the general population; intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common underlying histology in resected incidentalomas of the pancreas. Pancreatic asymptomatic cysts present an enormous challenge in terms of accurate diagnosis and management stratification. Incorporating molecular signatures of cystic precursor lesions into the diagnostic algorithm will likely become a standard of care for asymptomatic pancreatic cysts. High-risk individuals from familial pancreatic cancer kindreds are another group of individuals where knowledge of precursor lesions has had a therapeutic impact; sensitive imaging technologies have enabled the identification and subsequent resection of pancreatic cancer precursors in these high-risk individuals, preventing the progression to invasive cancer.

CONCLUSIONS

Precursor lesions of pancreatic adenocarcinomas represent a unique opportunity for diagnosis and intervention for a malignancy with near uniform lethality. Further studies on these precursors will enable the development of rational early detection and therapeutic strategies in order to ameliorate pancreatic cancer survival.

Solid-pseudopapillary neoplasm of the pancreas: Three cases with a literature review

Solid-pseudopapillary neoplasm of the pancreas is a very rare tumor. It most commonly occurs in young women and has unique pathologic features. Previous immunohistochemical studies demonstrated that most solid-pseudopapillary neoplasms were immunoreactive with antibodies directed against vimentin and neuron-specific enolase. Recently, expression of CD10 and CD56 in this tumor has been reported. In this report, we expanded the demographic profile, highlighting 3 cases of solid-pseudopapillary neoplasm of the pancreas that presented in an elderly woman, a young man, and a young woman and further characterized them histologically and immunophenotypically. Grossly, all 3 tumors were well circumscribed and had a variable degree of cystic formation, necrosis, and hemorrhage. Microscopically, these tumors were characterized by a pseudopapillary pattern of epithelioid cells arranged around a delicate fibrovascular core with sheets of bland epithelioid cells filling cystic spaces. Hyaline globules, cholesterol granulomas, and foamy cells were all seen to be common findings. Although these 3 tumors were strongly immunoreactive for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, neuron-specific enolase, CD10, CD56, and progesterone receptor, they demonstrated only variable "positivity" for epithelial membrane antigen and broad-spectrum cytokeratin, but were being consistently nonreactive for synaptophysin, insulin, glucogon, chromogranin A, and estrogen receptor. Interestingly, 2 of the 3 tumors were S-100 protein and melanin A reactive but were nonreactive for HMB45.

Impact of endoscopic ultrasound-guided fine needle biopsy for diagnosis of pancreatic masses

AIM: To evaluate the diagnostic accuracy of histological evaluation of pancreatic tissue samples obtained by a modified method for recovering and processing the endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) material in the differential diagnosis of pancreatic solid masses.

METHODS: Sixty-two consecutive patients with pancreatic masses were prospectively studied. EUS was performed by the linear scanning Pentax FG-38UX echoendoscope. Three FNAs (22G needle) were carried out during each procedure. The materials obtained with first and second punctures were processed for cytological study. Materials of the third puncture were recovered into 10% formol solution by careful injection of saline solution through the needle, and processed for histological study.

RESULTS: Length of the core specimen obtained for histological analysis was 6.5 ± 5.3 mm (range 1-22 mm). Cytological and histological samples were considered as adequate in 51 (82.3%) and 52 cases (83.9%), respectively. Overall sensitivity of both pancreatic cytology and histology for diagnosis of malignancy was 68.4%. Contrary to cytology, histology was able to diagnose tumours other than adenocarcinomas, and all cases of inflammatory masses. Combination of cytology and histology allowed obtaining an adequate sample in 56 cases (90.3%), with a global sensitivity of 84.21%, specificity of 100% and an overall accuracy of 90.32%. The complication rate was 1.6%.

CONCLUSION: Adequate pancreatic core specimens for histological examination can be obtained by EUS-guided FNA. This technique is mainly useful for the diagnosis of different types of pancreatic tumours and evaluation of benign diseases.

Cytomorphology and B72.3 labeling of benign and malignant ductal epithelium in pancreatic lesions compared to gastrointestinal epithelium

Endoscopic ultrasound-guided pancreatic fine-needle aspiration biopsy very frequently produces gastrointestinal epithelial contamination (GIC). We studied the cytomorphology and B72.3 immunoreactivity of lesional epithelium of benign and malignant ductal lesions of the pancreas and compared the findings to our previously established template of GIC. Air-dried smears, fixed smears, and ThinPrep (TP) specimens were obtained using a cytobrush, directly from benign and malignant ductal lesions of 18 Whipple specimens, to ensure purity of the epithelium studied. Smear background, cell architecture, and cellular features were analyzed. Immunocytochemical staining with B72.3 was performed in 14 cases. Epithelium of ductal carcinoma was distinguished from benign ductal epithelium in chronic pancreatitis and GIC primarily by crowded architecture and atypical cellular features, including high nuclear-to-cytoplasmic ratio, irregular nuclei, nucleoli, and vacuolated cytoplasm. Benign ductal and GIC epithelium were only distinguished by architecture (goblet cells and brush borders), but not consistently, especially gastric epithelium that lacked these features. B72.3 shows promise in the differentiation between GIC and benign and malignant ductal epithelium, with no staining supporting benign ductal cells, fine punctate perinuclear staining correlating with GIC, and strong cytoplasmic staining supporting malignancy.

Cystic pancreatic endocrine tumor

BACKGROUND

Most cystic pancreatic neoplasms are currently evaluated by an endoscopic ultrasound-guided fine-needle aspiration biopsy (FNAB). In the authors' experience, FNAB of cystic pancreatic endocrine tumors (PETs) frequently causes diagnostic difficulties, partly because of unexpected overlapping features with cystic ductal adenocarcinomas.

METHODS

The authors identified 5 histologically confirmed cystic PETs that were evaluated by FNAB and compared their cytomorphologic features to cystic ductal adenocarcinomas (n = 5) and solid PETs (n = 39) of the pancreas.

RESULTS

Cytologically, 2 of the aspirates of cystic PETs were devoid of tumor cells whereas the other 3 were variably cellular and composed of cohesive aggregates of monomorphic cellular elements with variably coarse chromatin. Tumor necrosis and nuclear membrane irregularities were not identified in cystic PETs. Alternatively, in contrast to PETs, cystic ductal adenocarcinomas were characterized by nuclear pleomorphism, nuclear membrane irregularities, and tumor necrosis.

CONCLUSIONS

Given the clinical implications, awareness of cystic PETs and their deceptive cytologic features would assist in distinguishing these lesions from cystic ductal adenocarcinomas.

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.

Advantage of EUS Trucut biopsy combined with fine-needle aspiration without immediate on-site cytopathologic examination

BACKGROUND

Endoscopic ultrasonographically guided fine-needle aspiration (EUS-FNA) is a safe and accurate method for obtaining diagnostic material from lesions within and immediately adjacent to the upper GI tract.

OBJECTIVE

To determine whether EUS Trucut biopsy (EUS-TCB) (Quickcore, Wilson-Cook, Winstom Salem, NC) can increase the accuracy of EUS-guided tissue sampling when combined with FNA when no cytopathologist is present.

DESIGN

Retrospective case review.

SETTING

University-based referral practice.

PATIENTS

All patients who had lesions that were accessible through the esophagus or stomach and that were greater than 20 mm and amenable to Trucut biopsy were included.

INTERVENTIONS

A total of 41 patients underwent both EUS-FNA and TCB with a separate pathologist evaluating each specimen.

MAIN OUTCOME MEASUREMENTS

The diagnostic performance of FNA, TCB, and its combination were compared.

RESULTS

The overall accuracy in our series was as follows: FNA, 76%; TCB, 76% (P not significant); and combination of FNA and TCB, 95% (P = .007). In the 26 patients with malignant diagnoses, the accuracy of combination was 100% versus 77% for FNA (P = .03). The median number of passes with the FNA and TCB was 4.4 (range 2-8) and 2.8 (range 2-5), respectively. One patient in the series had fever and chest pain after EUS biopsy.

LIMITATIONS

Retrospective study.

CONCLUSION

In our series EUS-TCB accuracy was equal to FNA when no on-site cytopathologist is present. TCB was helpful in the diagnosis of pancreatic masses, gastric submucosal lesions, lymphoma, and necrotic tumors. A 100% accuracy of FNA + TCB was seen in patients with malignant diseases and in patients who had failed or been refused biopsy by other modalities in the past. More data are needed before the exact role of TCB in the absence of on-site cytopathology can be accurately defined.

Fine-needle aspiration biopsy of hepatic lesions: computerized tomographic-guided versus endoscopic ultrasound-guided FNA

BACKGROUND

Computerized tomographic (CT)-guided fine-needle aspiration (FNA) cytology is a well-established tool in the diagnosis of hepatic lesions. Endoscopic ultrasound-guided FNA (EUS-FNA), developed recently and used predominantly in evaluating mediastinal and pancreatic lesions, provides access to a significant portion of the liver and to perihepatic structures not readily accessible by a percutaneous approach.

METHODS

A recent experience (1997-2002) with CT-guided FNA of liver lesions at the University of Alabama Birmingham (UAB) was compared with the first 2.5 years of EUS-FNA experience (2000-2002). Cases were identified using a SNOMED search and all reports and cytologic slides were retrieved for review.

RESULTS

In 6 years, 34 percutaneous CT-FNA liver biopsies were performed at UAB; in approximately 2.5 years, 16 EUS-FNA liver biopsies were done. In both groups the primary clinical indication was suspected metastatic carcinoma (CT, 41% of cases vs. EUS, 56%). The 2 techniques yielded a similar range of benign, atypical, and malignant diagnoses (CT: 26%, 18%, and 56% vs. EUS: 19%, 25%, and 56%). Because of the clinical setting in which EUS-FNA is usually performed, a much narrower range of neoplasms was sampled by EUS-FNA. Benign gastrointestinal epithelial cells were identified in 60% of the EUS-FNA specimens.

CONCLUSIONS

Early experience suggests EUS-FNA is comparable to CT-FNA in terms of diagnostic utility for hepatic lesions. Anatomy limits EUS-FNA to only a fraction of the hepatic parenchyma, but that fraction includes the hilum and left lobe of the liver and the proximal biliary tract. The gallbladder, extrahepatic biliary system, and perihilar lymph nodes are readily accessible. Proximate high-resolution ultrasound imaging and cytopathologist involvement in the EUS-FNA process are further advantages. Awareness of artifacts inherent in EUS-FNA sampling (i.e., gut epithelial cells) can minimize a potential diagnostic pitfall.

Intraductal papillary mucinous neoplasm of the pancreas: cytologic features predict histologic grade

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is an increasingly recognized cystic neoplasm of the pancreas, histologically classified by the degree of epithelial atypia and by the presence or absence of invasion of the cyst wall. To the authors' knowledge, the cytologic features of this neoplasm are poorly characterized, especially with respect to tumor grade.

METHODS

Thirty-three endoscopic ultrasound (EUS)-guided pancreatic fine-needle aspiration biopsy (FNAB) samples and 1 pancreatic duct brush specimen from 25 patients with a histologically confirmed IPMN were retrospectively reviewed. Blinded to tumor grade, background mucin, inflammation, necrosis, overall cellularity, the presence of gastrointestinal-contaminating epithelium, architecture of cell clusters, and nuclear and cellular morphology were evaluated. In cases in which special stains for mucin were performed, the diagnostic utility of these stains was assessed. These cytologic features were subsequently correlated with the histologic diagnosis.

RESULTS

The 34 cytology samples represented 4 adenomas, 15 IPMN-moderate dysplasias, 7 intraductal carcinomas, and 8 IPMNs with invasive carcinoma. Extracellular mucin was present in 97% of all cases; 53% had thick, viscous, "colloid-like" mucin. Special stains for mucin were positive in 6 of 11 cases (54%), helping to identify thin mucin in only 2 cases. Gastrointestinal contamination did not appear to create diagnostic difficulty due to an apparent dual (dysplastic-nondysplastic) epithelial population, but only 4 adenomas were evaluated in this study. Necrosis distinguished IPMN with carcinoma from IPMN-adenomas and IPMN with moderate dysplasia (P < .00001), and was more often observed with invasion than IPMN-carcinoma in situ (P < .05). Tight epithelial cell clusters with hyperchromatic nuclei and a high nuclear to cytoplasmic ratio was more significant in IPMN of at least moderate dysplasia (P = .03). Pale nuclei with parachromatin clearing was found to be a nuclear feature that was suspicious for at least carcinoma in situ (P < .001). In addition, significant background inflammation (neutrophils and histiocytes) was found to be more characteristic of IPMN with at least carcinoma in situ (P = .002).

CONCLUSIONS

The presence of thick, "colloid-like" mucin is noted in half of the IPMN cases, but was not found to be specific to grade. The absence of such mucin does not exclude an IPMN. The presence of tight epithelial cell clusters is consistent with a neoplasm of at least moderate dysplasia, and abundant background inflammation and parachromatin clearing correlated with the presence of at least carcinoma in situ. Necrosis was the only feature found to be strongly suggestive of invasion.

Barrett's esophagus with high-grade dysplasia simulating metastatic adenocarcinoma in a fine needle aspiration biopsy

An endoscopic ultrasound examination, performed to rule out invasive esophageal carcinoma in a patient with a history of Barrett's esophagus with high-grade dysplasia, disclosed an enlarged paraesophageal lymph node which was aspirated. The aspirate contained markedly atypical clustered large cells that displayed prominent nucleoli and mitoses, as well as lymphoid cells, suggestive of adenocarcinoma metastatic to a lymph node. The neoplastic-appearing cells were, in fact, dysplastic glandular cells that the needle traversed en route to a reactive lymph node. The case represents a rare instance in which Barrett's esophagus with high-grade dysplasia was discerned on fine needle aspiration (FNA) biopsy and highlights a potential pitfall in FNA.

Review of endoscopic ultrasound-guided fine-needle aspiration cytology

This review, based on the Hennepin County Medical Center experience and review of the literature, vastly covers the up-to-date role of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (FNA) in evaluating tumorous lesions of the gastrointestinal tract and adjacent organs. Emphasis is given to the tumoral and nodal staging of esophageal, pulmonary, and pancreatic cancer. This review also discusses technical, pathological, and gastroenterologic aspects and the role of the pathologist and endosonographer in the evaluation of these lesions, as well as the corresponding FNA cytology and differential diagnosis.

Determination of qualitative telomerase activity as an adjunct to the diagnosis of pancreatic adenocarcinoma by EUS-guided fine-needle aspiration

BACKGROUND

Telomerase activity is up-regulated in pancreatic cancer. Hence, measurement of telomerase activity in pancreatic needle-biopsy specimens could assist in establishing a positive diagnosis in specimens that are inadequate for cytology.

OBJECTIVE

To determine the sensitivity and specificity of telomerase activity for neoplasia in a series of EUS-guided fine-needle aspirate (EUS-FNA) biopsies of pancreatic mass lesions.

DESIGN

Prospective, consecutive, non-randomized cohort.

SETTING

Academic hospital, tertiary referral center.

PATIENTS

Seventy-one patients with a pancreatic mass diagnosed by cross-sectional imaging.

INTERVENTIONS

EUS-FNA of 52 solid and 18 cystic pancreatic lesions.

MAIN OUTCOME MEASUREMENTS

(1) Cytologic diagnosis; (2) tissue telomerase activity by semi-quantitative polymerase chain reaction; (3) patient demographics; (4) clinical outcomes.

RESULTS

Cytology results were positive for adenocarcinoma in 40 patients with a solid pancreatic mass; of these, telomerase activity was detected in 31. There were no telomerase false-positive results. Telomerase results were positive in 6 of the 7 patients (86%) who had negative cytology results and who eventually were found to have biopsy-proven adenocarcinoma. The sensitivity and specificity of telomerase activity for detecting pancreatic adenocarcinoma in solid masses was 79% (95% CI, 64%-89%) and 100% (95% CI, 55%-100%).

LIMITATIONS

Extremely high sensitivity and specificity of EUS-FNA cytology in solid lesions minimized the incremental benefit of telomerase.

CONCLUSIONS

Telomerase activity can be measured readily in specimens obtained at EUS-FNA and accurately predicts malignancy. Used in combination with cytology, telomerase increased the sensitivity from 85% to 98% while maintaining the specificity at 100%. Lesions with negative cytology result and positive telomerase activity should be evaluated aggressively to exclude malignancy.

Cytologic features and diagnostic pitfalls of primary ampullary tumors by endoscopic ultrasound-guided fine-needle aspiration biopsy

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-guided FNAB) is highly sensitive and specific in cytologic diagnosis and clinical staging of malignant neoplasms of the gastrointestinal tract, pancreas, liver, and lymph nodes. However, no study has been performed to evaluate its accuracy, sensitivity, specificity, and the cytomorphologic features of suspected primary ampullary tumors.

METHODS

All EUS-guided FNABs of suspected primary ampullary lesions at the University of California Irvine Medical Center (Orange, CA) from January 1998 to September 2004 were retrospectively retrieved. The number of passes necessary to arrive at a preliminary diagnosis during adequacy assessment was documented. The cytologic features were analyzed with endosonographic correlation. Follow-up information was also collected.

RESULTS

Thirty-five patients were found, 17 men and 18 women. The mean age of the patients was 68.9 years (range, 34-87 yrs). Adenocarcinoma was diagnosed in 13 patients. Atypical cells were found in six patients, four of which were suspicious for adenocarcinoma and two of which were consistent with reactive atypia. Adenoma was diagnosed in two patients and carcinoid tumor in one. Thirteen patients had a diagnosis that was negative for malignant cells. The average number of aspiration passes was 2.4 (range, 1-6 passes). Follow-up information was available in 27 patients. There were three false-negative results and no false-positive results. The sensitivity, specificity, and the positive and the negative predictive values were 82.4%, 100%, 100%, and 76.9%, respectively. The diagnostic accuracy was 88.8%. The consistent cytologic features in specimens that were positive or suspicious for adenocarcinoma included high cellularity, single cells, 3-dimensional cell balls, high nuclear-to-cytoplasmic ratio, prominent nucleoli, coarse/uneven distribution of chromatin, and necrosis.

CONCLUSIONS

EUS-guided FNAB was accurate, sensitive, and specific in the assessment of suspected primary ampullary masses. Adenoma presented a diagnostic challenge and endosonographic correlation was instrumental to increase the diagnostic accuracy.

Cytology of pancreatic acinar cell carcinoma

Acinar cell carcinoma (ACC) of the pancreas is extremely uncommon and its cytologic features have rarely been described. We describe the cytologic features of cases we have seen, review the literature regarding its cytologic features and discuss the pitfalls that may be encountered and the use of immunohistochemistry for its diagnosis. We searched our databases for all cases of histologically confirmed pancreatic ACC which had undergone prior fine needle aspiration (FNA) of the primary pancreatic lesion. The clinical histories, radiographic and sonographic findings, cytologic features, original cytologic diagnoses, and final histologic diagnoses were reviewed. Four cases of pancreatic ACC were found that had undergone FNA prior to histologic confirmation of the diagnoses. They were from 2 men and 2 women aged 50-75 yr. All masses were in the head of the pancreas, 2 had apparent peri-pancreatic adenopathy and 1 had an apparent liver metastasis. On review, all 4 had had diagnostic material on cytology samples. Original cytologic diagnoses included "acinar cell carcinoma," "pancreatic endocrine tumor," "favor neuroendocrine tumor, low-grade" and "non-diagnostic specimen." The cytologic features included small to moderate-sized loose groups with numerous single cells, prominent acinar formation, little anisonucleosis and prominent nucleoli. The cytologic features showed significant overlap with those of pancreatic endocrine tumors.

Cytologic diagnosis of pancreatic endocrine tumors by endoscopic ultrasound-guided fine-needle aspiration: A review

Precise localization and diagnosis of pancreatic endocrine tumors (PETs) is important, because pancreatic PETs have different clinical and biological behavior and treatment modalities than do exocrine pancreatic tumors. In contrast to the much more common exocrine adenocarcinomas, cytologic studies of PET are relatively rare and many cytopathologists lack experience with the cytomorphologic features of these tumors.During the last 10 yr, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has matured into an accurate, highly sensitive, and cost-effective modality for the preoperative localization of pancreatic PETs. This has resulted in an increased number of PETs first sampled as cytology specimens. This manuscript focuses on the cytomorphologic features most suggestive of pancreatic PETs, differential diagnosis, and diagnostic pitfalls of PETs. The technical development of EUS-guided FNA and the ancillary studies for pancreatic PETs are also reviewed. The data summarized in this review indicate that EUS-FNA is a valuable method in the recognition of pancreatic PETs and in most cases cytopathologists could reach a correct diagnosis of these tumors, including their hormone producing capability on aspirated cytologic material.

EUS-guided fine needle tissue acquisition by using high negative pressure suction for the evaluation of solid masses: a pilot study

BACKGROUND

The capability of obtaining tissue samples for histologic examination during EUS has theoretical advantages over cytology alone. The objective was to evaluate the feasibility and the yield of EUS-guided FNA tissue acquisition (EUS-FNTA) by using high negative pressure suction.

METHODS

The study design is a prospective, observational pilot study set at a tertiary referral center. Twenty-seven patients with a solid mass amenable to sampling with EUS were included in the study. FNA with a 22-gauge needle was used for a total of 5 passes. An additional pass with the same needle was performed by applying continuous high negative pressure suction using the Alliance II inflation system. The main outcome measurements were the rate of tissue acquisition and the diagnostic accuracy of EUS-FNTA.

OBSERVATIONS

Tissue samples were obtained in 26 of the 27 patients (96%). Malignancy was detected in 20 of the 26 biopsy specimens obtained by FNTA and in 20 of the 27 FNA specimens. In 3 patients, EUS-FNTA failed to disclose malignancy, which in two of the patients was diagnosed by FNA. Conversely, EUS-FNTA diagnosed a recurrent malignant thymoma and a schwannoma in two FNA-negative patients. In 3 patients with both FNTA and FNA negative for malignancy, a definitive diagnosis could not be established. Overall, diagnostic accuracy was 76.9% for both EUS-FNTA and EUS-FNA. When combined, a correct diagnosis was achieved in 84.6% of the patients. Immunostaining of the retrieved tissue allowed characterization of the primary tumor in 5 cases and the diagnosis of a schwannoma and two neuroendocrine tumors. Limitations of the study were small sample size and a pilot study.

CONCLUSIONS

EUS-FNTA has a high yield for the retrieval of core tissue samples. Further studies in which EUS-FNTA is performed before FNA and with variable number of passes are needed to better define its diagnostic role and performance characteristics.

Cytologic grade independently predicts survival of patients with pancreatic adenocarcinoma

Our objectives were to devise a cytologic grading system and determine whether it would predict survival of patients with solid-type pancreatic adenocarcinoma. We evaluated 116 consecutive patients from July 2000 to November 2002; they were followed up until September 2003. We scored the following features on rapid Romanowsky-stained endoscopic ultrasound-guided fine-needle aspiration smears: cell group architecture, single cells, nuclear grade, mucus, bizarre cells, and necrosis. A cytologic grade (low vs high) was assigned. The Kaplan-Meier estimate of 6-month survival was 76% (SE, 7%) for patients with low-grade tumors vs 50% (SE, 6%) for patients with high-grade carcinoma. The median survival for patients with low-grade vs high-grade tumors was 1 year vs 6 months, respectively (chi2 = 4.45; P = .035). Cox proportional hazards regression showed tumor stage, cancer-specific treatment, and cytologic grade to be independent predictors of survival (P = .001). No other factors (age, mass location, placement of stent, presence of concomitant chronic pancreatitis, race, sex) predicted survival. We devised a grading system that independently predicted survival in patients with pancreatic adenocarcinoma.

Fine-needle aspiration cytology of pancreatic somatostatinoma: the importance of immunohistochemistry for the cytologic diagnosis of pancreatic endocrine neoplasms

Pancreatic somatostatinoma is a rare pancreatic endocrine neoplasm representing as little as 1% of pancreatic endocrine neoplasms (PENs). The histologic features of this tumor are like those of other PENs, except that it commonly forms acinar structures and often has cells with abundant, granular cytoplasm. We have recently encountered two of these neoplasms sampled by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). We discuss the cytologic and immunohistochemical findings of these two cases and the cytologic similarities these neoplasms share with pancreatic acinar-cell carcinoma (PACC). We review the cytologic features of PEN and PACC and discuss the importance of cell block immunohistochemistry in the diagnosis of pancreatic neoplasia sampled by EUS-guided FNA.

EUS-guided FNA combined with flow cytometry in the diagnoses of suspected or recurrent intrathoracic or retroperitoneal lymphoma

BACKGROUND

Limited data exist on the combined use of EUS-guided FNA (EUS-FNA) and flow cytometry (FC) in the diagnosis of lymphoma. The aim of this study was to evaluate the accuracy of EUS-FNA combined with FC in the diagnosis of primary or recurrent lymphoma.

METHODS

This study was a retrospective analysis of a prospective collection of data over a 3-year period. Over 3 years, 29 patients with lesions (n=31) suspicious for lymphoma underwent EUS-FNA and FC.

RESULTS

Of the 29 patients, 10 patients had lymphoma and 17 patients had nonlymphoma lesions; for two patients, final diagnosis was indeterminate because of insufficient material for FC. The lymphoma cases included non-Hodgkin's lymphoma (n=6, including 3 recurrences), mucosa-associated lymphoid tissue (MALT) lymphoma (n=2), a non-GI lymphoma with mediastinal lymphadenopathy (n=1), and an uncharacterized lymphoma (n=1). Of the 31 lesions, 8 were true positive, 18 were true negative, and 3 were false negative; for two lesions, we could not determine the final diagnosis. No false-positive results were encountered. The sensitivity, the specificity, and the accuracy of EUS-FNA combined with FC for diagnosing lymphoma were 72.7%: 95% CI [43.3%, 90.3%], 100%: 95% CI [82.4%, 100.0%], and 89.7%: 95% CI [73.6%, 96.4%], respectively. Limitations to this study include a short duration of follow-up and a lack of a surgical criterion standard.

CONCLUSIONS

EUS-FNA in combination with FC allows the diagnosis of primary suspected or recurrent lymphoma. It also is an adjunct in staging MALT lymphoma and could direct clinicians toward further investigative procedures.

The emerging role of endoscopic ultrasonography in cancer staging

The management of solid organ cancers relies on accurate staging. Once distal metastasis has been excluded by conventional radiographic methods, local staging of the tumor and its nodal involvement is essential to determine the most optimal therapeutic approach. Many radiographic imaging modalities are unable to determine subtle tumor involvement. However, the emergence of endoscopic ultrasonography (EUS) has given promise to improved staging with its unique ability to examine tumors from within the gastrointestinal lumen with extremely close proximity. An additional advantage is the ability to perform fine-needle aspiration (FNA) biopsy to confirm or exclude tumor involvement. Many studies have shown superior accuracy in staging with EUS and EUS-FNA for tumors of the esophagus, stomach, pancreas, rectum, and mediastinum, including lung cancer. This review illustrates the principles of EUS and its role in staging of a variety of cancers and particularly its role alongside other imaging modalities.

Pancreatic FNA in 1000 cases: a comparison of imaging modalities

BACKGROUND

Image-guided FNA is a popular method for evaluating pancreatic lesions, but few large studies on pancreatic FNA exist.

METHODS

Cytologic material, imaging reports, and clinical follow-up information were reviewed from pancreatic FNA cases performed over a 5-year period.

RESULTS

A total of 1050 pancreatic FNAs were obtained by EUS (n = 843), US (n = 140), and CT (n = 67). On-site assessment was performed in 89.2% (n = 937) of cases. Findings were as follows: positive for neoplasm 48.9% (n = 503), negative 29.1% (n = 306), descriptive 10% (n = 105), suspicious 5.9% (n = 62), atypical/inconclusive 4.6% (n = 48), and nondiagnostic/inadequate 1.5% (n = 26). Follow-up in the form of histology or at least 6 months of clinical observation was available for 61.2% (n = 643). There was an overall false-positive rate of 0.3% and a false-negative rate of 14.3%. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were as follows: 79.4, 99.0, 99.4, 67.9, 84.5 for the total series, respectively; 79.9, 98.8, 99.2, 72.5, 86.5 for EUS, respectively; 77.9, 100, 100, 48.6, 81.7 for US, respectively; and 78.6, 100, 100, 47.1, 82.0 for CT, respectively. In general, accuracy was not influenced by lesion size or site, number of FNA passes, or number of procedures per patient. After controlling for lesion size, EUS resulted in greater accuracy than US or CT when evaluating lesions <3 cm ( p = 0.015).

CONCLUSIONS

All imaging modalities showed moderate to high sensitivity, specificity, and accuracy. Logistic regression analysis showed that for lesions <3 cm, the EUS method had higher accuracy than US or CT. No statistically significant difference was seen for larger lesions or for the number of FNA passes.

Pitfalls in endoscopic ultrasound-guided fine-needle aspiration and how to avoid them

Although a broad range of pancreatic, gastrointestinal, thoracic, and abdominal pathology may be sampled by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA), certain difficulties tend to recur because of the frequency of certain sample types and because of the nature of their individual cytomorphologic profiles. With this in mind, we review certain pitfalls that may befall cytopathologists with EUS-guided FNA. We discuss the diagnosis of pancreatic ductal adenocarcinoma and of other pancreatic epithelioid tumors including pancreatic endocrine neoplasms, solid pseudopapillary tumors, and acinar cell carcinomas. We also discuss the diagnosis of pancreatic cystic neoplasia including intraductal papillary mucinous neoplasms and mucinous cystic neoplasms and the diagnosis of gastrointestinal mesenchymal neoplasia with particular attention to gastrointestinal stromal tumors. Finally, we discuss the interpretation of lymph node aspirates.

Cytomorphology of gastric and duodenal epithelium and reactivity to B72.3: A baseline for comparison to pancreatic lesions aspirated by EUS-FNAB

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has become a widely used method of pre-operatively evaluating pancreatic masses. This technique introduces gastrointestinal contamination into the specimen, which poses a diagnostic pitfall. The cytomorphologic features of these contaminants have not been fully characterized. The current study was designed to systematically document the cytomorphology of gastric and duodenal epithelium on fixed and air-dried smears, as well as ThinPrep (TP) preparations, and to assess the reactivity of the epithelial cells to the tumor marker B72.3 so as to establish a baseline for future comparative studies with EUS-FNAB of the pancreas. Air-dried and fixed smears and TP specimens were obtained using a cytobrush from gastric (GM) and duodenal (DM) mucosa from 14 Whipple specimens. Cytologic features of cell architecture, cellular features and smear background were analysed. Immunocytochemical staining with B72.3 was performed in 10/14 cases. Mucin was present in all preparations except one case from the duodenum. It was consistently present as isolated thick to thin clumps but never as diffuse 'colloid-type' mucin; it was most prominent on air-dried smears, and most abundant from the GM. Epithelial cells were admixed with mucin, but degenerated cells and inflammation were not present within the mucin. Mucin on TP appeared as fragmented wisps of pale blue staining material. Background inflammation and debris were not significant findings. The epithelial cells were arranged in large and small monolayered sheets. Smaller groups were more common from GM on smears and more abundant on TP than smears. Luminal edges (DM>GM) were a prominent feature, with a brush border noted in DM. The nuclei of GM and DM were round, evenly spaced and without atypia, and dense, non-vacuolated cytoplasm was the rule, with the exception of goblet cells and occasional gastric foveolar cells noted in one case. In both GM and DM, B72.3 stained goblet cells with a strong, coarsely granular pattern and stained epithelial cells focally in a finely granular, punctate, perinuclear distribution; mucin also stained strongly in all cases. These baseline characteristics provide a template for assessing mucin and epithelial GM and DM contamination on pancreatic EUS-FNAB specimens.

Sampling of the adrenal glands by endoscopic ultrasound-guided fine-needle aspiration

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has proven to be a valuable modality for the primary diagnosis and staging of gastrointestinal, and perigastrointestinal malignancy. Aside from assessing thoracic and abdominal lymph nodes and the liver for metastases, EUS can assess and sample the adrenal glands, which are frequently involved by metastatic disease, but can also harbor benign primary neoplasms. The cytology files at our institution were reviewed for all cases of EUS-guided FNA of the adrenal glands. Clinical histories, sonographic findings, and cytologic findings of all cases were reviewed. Results were compared with overall EUS-guided FNA performance and the performance of non-EUS-guided FNA of the adrenal. The utility of cell block immunohistochemistry (IHC) in these cases was reviewed. Between 1/1/00 and 5/15/04 there were 24 cases of EUS-guided FNA of the adrenal gland from 22 different patients (13 men; 9 women) at our institution. This represented 1.4% of overall EUS-guided FNA and 77% of adrenal gland FNA. Patient ages ranged from 37 to 86 yr (mean 69 +/- 11 yr). Most patients had other cancers or mass lesions and were being staged at the time of the procedure (19 of 22). Almost all FNAs were of the left adrenal gland (23 of 24). Lesion size ranged from 0.9 to 7.9 cm (mean 2.5 +/- 1.6 cm). Diagnostic material was present in all cases when compared with an overall EUS-guided FNA diagnostic rate of 88%. Material for cell block was present in 21 cases, and IHC was used in 3 cases. Final diagnoses were as follows: cortical tissue consistent with cortical adenoma (19), metastatic adenocarcinoma (3), pheochromocytoma (1), and adrenal cortical carcinoma (1). EUS-guided FNA of the adrenal gland is primarily used in the staging of other malignancies when lesions of the left adrenal are recognized sonographically. Diagnostic tissue is easily obtained, including material for cell block IHC, which allows definitive diagnosis in cases that present difficult differential diagnoses.

Endoscopic ultrasound-guided fine-needle aspiration biopsy of the adrenal glands: analysis of 24 patients

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy allows the detailed imaging and FNA not only of both intramural and extramural structures and lesions of the gastrointestinal (GI) tract but also of various intraabdominal organs. Thus, EUS-FNA biopsy offers a novel opportunity to evaluate and obtain cytology samples from adrenal gland lesions. The objective of the current study was to determine the utility of EUS-FNA in the diagnosis of adrenal lesions.

METHODS

The authors conducted a prospective evaluation of 24 consecutive EUS-FNA biopsy specimens obtained from patients with adrenal lesions. An attending cytopathologist was present on site to assess specimen adequacy and to provide rapid interpretation of air-dried material that had been stained with Diff-Quik (Baxter Scientific Products, McGraw Park, IL). Additional samples were obtained for ThinPrep (Cytyc Corporation, Boxborough, MA) preparation, and cell blocks subsequently were prepared. Appropriate immunohistochemical staining was performed as indicated. The cytologic diagnosis was then analyzed for correlations with the final diagnosis, which was based on relevant correlative cytologic or histologic examination of biopsied/resected pathology materials and/or final clinical follow-up.

RESULTS

In total, 24 EUS-FNA biopsy specimens (from 18 males and 6 females) were obtained from adrenal glands. The mean patient age was 62.2 years (range, 48-81 years). Adequate cellularity was noted in all 24 samples. Seven of 24 samples (29%) were reported to be positive for carcinoma. All samples that were diagnosed as metastatic carcinoma were confirmed on subsequent follow-up. EUS-FNA performed simultaneously with adrenal gland aspiration either from the primary site (n = 1) or from metastases to lymph nodes (n = 3) supported diagnoses of metastatic carcinoma. Six of seven samples were metastatic from the lung, and one specimen was a direct extension of a transitional renal cell carcinoma. EUS-FNA biopsy of the right adrenal gland in one patient revealed myelolipoma. In 16 patients, benign adrenal gland cells were noted on EUS-FNA biopsy specimens from enlarged adrenal glands. In 5 samples (31%), signs of adenoma were evident. Morphology alone could not distinguish between adrenal adenoma and adrenal hyperplasia. No significant complications were reported after EUS-FNA biopsy of adrenal glands.

CONCLUSIONS

EUS-FNA biopsy is a highly specific and safe technique for confirming the diagnosis of carcinoma metastatic to the adrenal glands. Along with cytologic evaluation, EUS imaging is needed to support the diagnosis of adrenal adenoma.

Endoscopic ultrasound-guided fine-needle aspiration biopsy: a powerful tool to obtain samples from small lesions

BACKGROUND

Endoscopic ultrasound (EUS) is a powerful imaging modality to identify and determine the extent of a lesion. In addition, EUS is superior to a computed tomography scan in detecting lesions < 3 cm. The objective of the current study was to determine whether small lesions (< or = 25 mm) affected the specimen adequacy and the diagnostic accuracy for lesions aspirated under EUS guidance.

METHODS

In the current study, 209 consecutive EUS-guided fine-needle aspiration biopsy (EUS-FNAB) samples < or = 25 mm (100 samples) or > 25 mm (109 samples) as determined by EUS were obtained from 151 patients with a mean age of 62 years (range, 39-94 years). A cytopathologist present in the endoscopy suite determined specimen adequacy. Yield of adequate samples for diagnosis, number of passes, and operating characteristics of EUS-FNAB for small (< or = 25 mm) and large lesions (>25 mm) were compared.

RESULTS

The overall yield of obtaining adequate samples for diagnosis was 96% (201 of 209). There was no difference noted with regard to the yield of obtaining samples (96% vs. 96%) from small or large lesions. A mean of 2.5 passes (range, 1-9 passes) was needed to obtain adequate samples from lesions < or = 25 mm, whereas a mean of 4.5 passes (range, 1-11 passes) was needed to obtain adequate samples from lesions > 25 mm. The sensitivity (96% vs. 96%), specificity (100% vs. 100%), and diagnostic accuracy (98% vs. 97%) for EUS-FNAB were comparable whether the lesion was < or = 25 mm or > 25 mm.

CONCLUSIONS

EUS-FNAB was a highly effective technique to obtain samples from small (< or = 25 mm) and large (> 25 mm) lesions without affecting the sensitivity, specificity, or diagnostic accuracy.