Pancreatic fine-needle aspiration cytology in patients < 35-years of age: a retrospective review of 174 cases spanning a 17-year period

Cytopathology of solid pancreatic neoplasms: An algorithmic approach to diagnosis

The classification and management of solid pancreatic neoplasms has expanded significantly in recent years because of advances in immunohistochemical markers, molecular diagnostics, and therapeutics. Solid pancreatic masses are subdivided into 1) ill-defined, scirrhous, and stroma-rich (ductal adenocarcinoma) and 2) well circumscribed, cellular, and stroma-poor (including neuroendocrine neoplasms, acinar cell carcinoma, pancreatoblastoma, and solid-pseudopapillary neoplasm). Definitive diagnosis, particularly of stroma-poor, circumscribed tumors, requires the incorporation of radiologic and cytologic findings, along with the judicious use of (broad, but limited) immunohistochemical panels (pancytokeratin and neuroendocrine [synaptophysin], acinar [trypsin], and solid-pseudopapillary neoplasm [β-catenin] markers), along with unstained slides. Depending on the initial results, immunohistochemical panels should be expanded to include more confirmatory (acinar and neuroendocrine) markers. This ensures that adequate material is available for definitive diagnosis/subclassification and, in some cases, grading, and/or molecular studies, particularly of grade 3 neuroendocrine neoplasms and mixed-lineage tumors. The objective of this review is to expand the understanding of the cytomorphology of solid pancreatic neoplasms using an integrated, multidisciplinary approach in their diagnosis. Knowledge and understanding of recent updates in the classification of solid pancreatic neoplasms ensures that cytopathologists appropriately triage specimens, judiciously use and interpret ancillary studies, and incorporate these results in reporting.

Adult pancreatoblastoma: Current concepts in pathology

Adult pancreatoblastoma is an exceptionally rare malignant tumour of the pancreas that mimics other solid cellular neoplasms of the pancreas, which may pose diagnostic difficulties. Because of its rarity, little is known about its clinical and pathologic features. This article reviews the clinical and pathologic features of pancreatoblastoma in adults including differential diagnosis, treatment, and follow-up. Although pancreatoblastoma commonly occurs in childhood, there have now been more than 70 adult pancreatoblastomas described in the literature. There is a slight male predominance. There are no symptoms unique to pancreatoblastomas and adult patients are frequently symptomatic. The most common presenting symptom is abdominal pain. Grossly, the tumours are often large and well-circumscribed. Microscopically, pancreatoblastomas are composed of neoplastic cells with predominantly acinar differentiation and characteristic squamoid nests. These tumours are positive for trypsin, chymotrypsin, lipase, and BCL10. Loss of heterozygosity on chromosome 11p is the most common molecular alteration in pancreatoblastomas. Adult pancreatoblastomas are aggressive tumours with frequent local invasion, recurrence, and distant metastasis. Treatment consists of surgical resection. Chemotherapy and radiotherapy may have a role in the treatment of recurrent, residual, unresectable, and metastatic disease. It is important to distinguish pancreatoblastomas from morphological mimics such as acinar cell carcinomas, solid pseudopapillary neoplasms, and pancreatic neuroendocrine neoplasms.

Pancreatoblastoma: Cytologic and histologic analysis of 12 adult cases reveals helpful criteria in their diagnosis and distinction from common mimics

BACKGROUND

Pancreatoblastoma (PBL) is a rare malignant pancreatic tumor seen predominantly in childhood, and its cytologic diagnosis remains challenging.

METHODS

Twelve fine-needle-aspirations from 11 adults were analyzed.

RESULTS

In total, 6 men and 5 women (median age, 45 years; age range, 32-60 years) had tumors measuring a median 5.6 cm (range, 2.5-12 cm) located in the pancreatic head (n = 7) or tail (n = 4), including 3 with familial adenomatous polyposis (FAP)/FAP-related syndromes and 4 with metastasis at diagnosis. The median follow-up was 39.8 months (range, 0.8-348 months), and 5 patients died of disease. The original cytology diagnoses were: PBL (n = 2), neuroendocrine neoplasm (n = 2), poorly differentiated neuroendocrine carcinoma (n = 2), well differentiated neuroendocrine tumor (n = 1), poorly differentiated carcinoma (n = 2), "positive for malignancy" (n = 1), acinar cell carcinoma (n = 1), and epithelioid neoplasm with endocrine and acinar differentiation versus PBL (n = 1). Universal cytopathologic findings included hypercellularity; 3-dimensional clusters; and single, monotonous, blast-like cells that were from 1.5 to 2.0 times the size of red blood cells with high nuclear-to-cytoplasmic ratio, fine chromatin, small, distinct nucleoli, and a resemblance to well differentiated neuroendocrine tumor and poorly differentiated neuroendocrine carcinoma. Branching pseudopapillae (n = 7) and grooved nuclei (n = 3) raised the differential diagnosis of solid-pseudopapillary neoplasm, but with more atypia. Uncommon features included pleomorphism (n = 4) and numerous mitoses (n = 1). Squamoid morules were seen on smears (n = 5) or cell blocks (n = 6) in 70% of patients and were characterized by epithelioid cells with elongated, streaming nuclei, fine chromatin, absent nucleoli, and positive nuclear β-catenin (n = 6 of 8). The median Ki-67 index was 21% (range, 2%-70%), and neuroendocrine marker expression was common (100%), but acinar markers were variable (63%).

CONCLUSIONS

A combination of cytologic findings in PBL, including a predominant population of primitive blast-like cells, subtle squamoid morules, frequent neuroendocrine and variable acinar phenotype, should facilitate accurate cytologic diagnosis and distinction from common mimics.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

Biliary Brush Cytology Revisited

PURPOSE

To evaluate the diagnostic yield of biliary brush cytology and the factors affecting positive results in patients with biliary strictures.

PATIENTS AND METHODS

The medical records of all patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with biliary brush cytology at our institution from November 2004 to December 2013 were reviewed in this retrospective study. The yield of positive brush cytology and the factors affecting positive yield, such as stricture location, age, gender and preprocedure CA 19.9 level were assessed. The final histopathology, diagnosis obtained by other methods, such as endoscopic ultrasound-guided fine-needle aspiration cytology, CT scan, Tru-Cut biopsy and/or clinical/radiological follow-up were used to identify true- and false-positive/negative results. The brush cytology results were divided into 4 main categories: malignant, benign, atypical cells and inadequate.

RESULTS

A total of 1,168 patients underwent ERCP during this 9-year period. Out of these, 142 patients had ERCP and biliary brushings for diagnosis. The mean age of the patients at presentation was 58.7 years (range 23-84 years; 64.8% males). The indication for referral was obstructive jaundice in all patients. Of the 142 patients, 77 (54.2%) had a distal common bile duct (CBD) stricture and 65 (45.8%) had a proximal /complex hilar stricture. The strictures were classified as proximal or distal, based on their relationship with the cystic duct; those below the cystic duct insertion were classified as distal and those above it were considered proximal. The diagnostic yield of brush cytology was 58.5%. The diagnostic yield was higher for proximal than for distal CBD strictures (67 vs. 50%; p = 0.047). It was also higher for females (58 vs. 57.6%; p = 0.94), patients >50 years (60 vs. 50%; p = 0.29) and those with a CA 19.9 level >300 IU/ml (59.4 vs. 55.5%; p = 0.65) but did not reach statistical significance for any of these parameters. Complete follow-up data were available for 96 patients and 46 patients were lost to follow-up. The sensitivity, specificity, positive predictive value and negative predictive value were 65.3, 100, 100 and 27%, respectively. When patients with atypia were included in the group with positive results, the diagnostic yield increased to 65.5% with a diagnostic sensitivity of 68.6%. There were 27 false-negative diagnoses, 10 patients were true-negative and no patients had a false-positive diagnosis.

CONCLUSION

Biliary brush cytology is a safe and simple initial diagnostic procedure in patients with biliary strictures and can be performed at the time of therapeutic ERCP. If performed correctly and then interpreted by a dedicated cytopathologist, it has a good diagnostic yield and sensitivity. We feel that the low rates of success with this technique reported in some earlier studies have led to a feeling that this is not a particularly useful technique. We recommend that this topic should be revisited, and that the technique should be used more often.

Diagnostic Differentiation of Pancreatic Neuroendocrine Tumor From Other Neoplastic Solid Pancreatic Lesions During Endoscopic Ultrasound-Guided Fine-Needle Aspiration

OBJECTIVES

To identify factors differentiating pancreatic neuroendocrine tumors (PNETs) from non-PNET neoplastic solid pancreatic lesions (SPLs) and assess the accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).

METHODS

This is a retrospective study at a tertiary center of consecutive patients referred for EUS from 2004 to 2011. The main outcomes were pretest predictors and accuracy of EUS-FNA for diagnosis of PNET.

RESULTS

Among a total of 1108 EUS-FNAs for pancreatic lesions, 672 patients (PNET = 91, non-PNET neoplastic-SPLs = 581) had neoplastic-SPLs. The sensitivity, specificity, and accuracy of EUS-FNA for diagnosis of PNETs were 98.9%, 100%, and 99.9%, respectively. The mean needle-passes were 3.0/patient. The EUS volume (mean/year per endosonographer) in preceding 3 years significantly correlated with fewer needle passes (rs: [-0.26]; P = 0.02).Multivariate analysis demonstrated that patients with PNET when compared to non-PNET neoplastic-SPLs were younger (odds ratio [OR], 3.23; 95% confidence interval [95% CI], 1.19-9.09; P = 0.001), have 2 or more pancreatic lesions (OR, 5.63; 95% CI, 1.74-18.2; P = 0.005), and lower CA 19-9 values (OR, 10.0; 95% CI, 3.13-33.3; P = 0.001). Further, PNETs were less likely to have weight loss (OR, 0.40; 95% CI, 0.17-0.90; P = 0.03), current smoking (OR, 0.47; 95% CI, 0.22-0.98; P < 0.05), pancreatic ductal dilation (OR, 0.28; 95% CI, 0.13-0.60; P = 0.002), or imaging evidence of arterial invasion (OR, 0.22; 95% CI, 0.07-0.71; P = 0.01).

CONCLUSIONS

Although pre-FNA findings can reliably characterize, EUS-FNA is highly accurate for the diagnosis of PNETs.

Pretest prediction and diagnosis of metastatic lesions to the pancreas by endoscopic ultrasound-guided fine needle aspiration

BACKGROUND AND AIM

Early diagnosis of solid pancreatic lesions (SPLs) enables prompt treatment. The study aims to identify factors differentiating metastatic lesion to the pancreas (PMET) from pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (PNETs).

METHODS

This is a retrospective study at a tertiary cancer center. Consecutive patients referred for endoscopic ultrasound (EUS) of SPLs from 2004 to 2011 were reviewed. The main outcomes were pre-EUS-FNA (endoscopic ultrasound-guided fine needle aspiration) predictors and diagnostic accuracy of EUS-FNA for PMETs.

RESULTS

Among a total of 1108 EUS-FNAs for pancreatic lesions, 672 patients had neoplastic SPLs (PMETs = 53; PDACs = 528, PNETs = 91). The sensitivity, specificity, positive predictive value, and accuracy of EUS-FNA for diagnosis of PMETs were 84.9%, 100%, 100%, and 98.8%, respectively. The mean number of EUS-FNA passes for diagnosis of PMET was 3.1 per patient. For each endosonographer, preceding 3-year EUS volume (mean/year) significantly correlated with fewer needle passes (rs [-0.30], P = 0.03). The most common PMET was renal cell carcinoma. Stratified multivariate analyses were performed. Compared with patients with PDACs, PMETs were more common in men (odds ratio [OR] = 2.0; 95% confidence interval [CI] = 1.0-4.0); located in the pancreatic tail (OR = 2.4; 95%CI = 1.1-5.2); and were less likely with increasing age (OR = 0.95; 95%CI = 0.92-0.99), presence of major symptoms (abdomen pain/diarrhea/weight loss; OR = 0.2; 95%CI = 0.1-0.4), elevated bilirubin (OR = 0.3; 95%CI = 0.13-0.69), and imaging evidence of arterial invasion (OR = 0.15; 95%CI = 0.03-0.67). Compared with PNETs, PMETs were more common with increase age (OR = 1.05; 95%CI = 1.02-1.08) and increasing lesion size (OR = 1.03; 95%CI = 1.0-1.1), and were less likely in patients with diabetes (OR = 0.34; 95%CI = 0.11-0.99).

CONCLUSION

Among the largest numbers of neoplastic SPLs evaluated at a single center, pre-test features reliably characterize, and EUS-FNA provides a highly specific diagnosis of PMETs.

Adult pancreatoblastoma: A case report and review of the literature

The present study describes the case of a 24-year-old patient who presented with obstructive jaundice and weight loss, and was diagnosed with pancreatoblastoma (PB). Abdominal imaging studies revealed a heterogenous lesion of the pancreatic head with dilatation of the common bile duct. The patient underwent pancreaticoduodenectomy, however, three months after surgery multiple liver and bone metastases were identified on follow-up computed tomography scans. Despite treatment with four cycles of systemic chemotherapy and five courses of radiofrequency ablation, the patient succumbed due to tumour dissemination 13 months after initial diagnosis. PB is a malignant tumour of the pancreas that typically occurs in the pediatric population. The aim of the present study was to highlight the aggressive behavior of this rare clinical entity, focusing on the pitfalls of pre-operative diagnosis and the lack of management strategy guidelines in adults. Preoperative diagnosis of PB based on radiographic features may be difficult, as the imaging characteristics are non-specific. Furthermore, cytology may also be misleading, as the neoplasm consists of multiple cell lines (acinar, ductal and neuroendocrine cells) and diagnosis depends largely on the identification of the distinctive histological characteristic of squamoid corpuscles, which present as nests of flattened cells with a squamous appearance. Despite the use of surgical resection and adjuvant chemoradiotherapy for the treatment of this malignancy, its aggressive nature means that PB is associated with a poor prognosis in adult patients.

Sensitivity of alternative testing for pancreaticobiliary cancer: a 10-y review of the literature

BACKGROUND

Biliary strictures present a diagnostic challenge to differentiate benign disease from hepatopancreaticobiliary (HPB) malignancies. Endoscopic retrograde cholangiopancreatography cytology is commonly performed in these patients; however, its sensitivity for diagnosis of HPB malignancy is poor (41.6%). Many adjunctive tests have been investigated to improve the sensitivity of HPB biopsies. To determine the best tests available, however, we reviewed the literature and performed a comparative analysis of all recently investigated tests and their sensitivities.

METHODS

A PubMed search identified articles published between 2003 and 2014, describing alternate methods for diagnosing HPB malignancies, reported sensitivity, final pathology, and had data available online. Meta-analysis was conducted for tests with multiple articles. Tests with the highest sensitivity and specificities were reported.

RESULTS

A total of 77 studies were identified. Meta-analysis was performed on the sensitivity of EUS-FNA (74.2%), fluorescence in situ hybridization (54.2%), immunostain of insulin-like growth factor 2 mRNA-binding Protein 3 (IMP3; 80.4%), IMP3 + cytology (86.4%), K homology domain containing protein overexpressed in cancer (KOC; 85.9%), S100P (77.8%), serum CA19-9 (69.3%), and K-ras mutations (47.0%) to detect malignancy. Ultimately, 12 tests were identified with superior sensitivity (85.3%-100%) and specificities (81.6%-100%) including stricture scrapping, brush sectioning, IMP3 stain + cytology, IMP3+S100A4, bile carcinoembryonic cell adhesion molecule 6 protein (±CA19-9), bile micro RNA (miRNA)-135b, serum miRNA-RNU2-1f, serum miRNA-21 (+CA19-9), peripheral blood mononuclear cells miRNA-27a-3p (+CA19-9), serum miRNA-16 + miRNA-196a (+CA19-9), peripheral blood mononuclear cells mRNAs h-TERT + CK20 + CEA + C-MET.

CONCLUSIONS

We recommend immunostaining with a panel of IMP3+KOC + S100A4 + cytology to achieve maximum sensitivity and specificity from HPB biopsies. One biliary protein (carcinoembryonic cell adhesion molecule 6) and several RNAs (bile and blood) offer exceptional sensitivity and specificity and should be tested prospectively in larger populations. Overall, this review identifies several tests to improve the sensitivity of diagnostic algorithms to identify HPB malignancies.