Endoscopic ultrasound-guided fine-needle aspiration diagnosis of Merkel cell carcinoma metastatic to the pancreas.

Merkel cell carcinoma (MCC) is a rare and highly aggressive primary neuroendocrine carcinoma of the skin with a high propensity for local, regional, and distant spread. Distant metastasis of MCC to the pancreas is uncommonly seen and may impose a diagnostic challenge cytologically. Here we report a case of MCC with pancreatic metastasis, which was diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The aspirates revealed both single and clustered epithelial cells with scant cytoplasm and round nuclei with stippled chromatin and inconspicuous nucleoli. Immunocytochemically, the tumor cells were positive for CK20, synaptophysin, CD56, and CD117. The neoplastic cells were also identified by flow cytometry as non-hematopoietic cells which were positive for CD56 and negative for CD45. To our knowledge, this is only the second case report of MCC metastatic to the pancreas diagnosed by EUS-FNA. There have been several reports of MCC metastatic to the pancreas diagnosed only at the time of surgical resection. However, a preoperative diagnosis allows for appropriate management while sparing a patient the morbidity of unnecessary procedures.

Comparing two methods of detection for Chlamydia trachomatis in liquid-based Papanicolaou tests.

This study compared the performance of Chlamydia trachomatis testing using 2 methods: the BD ProbeTec Chlamydia trachomatis Q(x) Amplified DNA Assay (CTQ) on the BD Viper System with XTR technology (CTQ assay) and the Hybrid Capture (HC) 2 assay. A total of 1,054 Surepath and ThinPrep specimens were tested for C trachomatis nucleic acids using the CTQ assay and the HC2 assay. For positive and discrepant C trachomatis test results, confirmatory test for C trachomatis was performed using a reverse transcriptase-polymerase chain reaction. Of 1,054 liquid-based gynecologic cytology samples tested for C trachomatis using both assays, 1,041 tested negative on both. In 6 (0.57%) samples, findings were discordant. The CTQ assay and the HC2 assay had sensitivity rates of 100% and 66.7%, respectively, with comparable specificity (99.9%). The positive predictive values were 92.3% and 88.9% with the CTQ and HC2 assays, respectively. In this study, the CTQ assay was found to be more sensitive than the HC2 assay in detecting chlamydial infection; the CTQ assay also demonstrated a higher positive predictive value.

The value of onsite adequacy assessment of thyroid fine-needle aspirations is a function of operator experience.

BACKGROUND: Cytotechnologists and pathologists often perform onsite evaluations of thyroid fine-needle aspirations (FNAs) to provide immediate feedback regarding whether adequate material has been obtained for cytologic diagnosis. The current study was designed to determine whether onsite adequacy assessment results in a significant decrease in nondiagnostic specimens between ultrasound (US)-guided FNAs of the thyroid and those performed by palpation alone. METHODS: A search was performed to identify in-house thyroid FNAs performed between January 1, 2000 and December 31, 2003 that were obtained under US guidance or by palpation only. It was then recorded whether an onsite adequacy assessment was performed. The submitting physician and final diagnosis also were recorded for each case. Contingency tables were constructed and evaluated using chi-square analysis. RESULTS: Of 1502 in-house thyroid FNAs included in the current study, 981 (65.3%) were performed under US guidance and 521 (34.7%) were performed with palpation alone. Onsite adequacy assessment of the aspirated material was performed in 323 cases (21.5%), whereas 1179 cases (78.5%) were performed without onsite evaluation. Of the 418 palpation-guided FNAs that were performed without adequacy assessment, 70 (16.7%) were reported to be nondiagnostic, whereas of the 103 palpation-guided FNAs with immediate evaluation, only 7 (6.8%) were determined to be inadequate for diagnosis. This difference was statistically significant (P < 0.025). Of 761 US-guided FNAs without immediate adequacy assessment, 54 (7.1%) were nondiagnostic, which was not statistically different from the nondiagnostic rate of 4.5% (10 of 220 cases) for US-guided FNAs with onsite evaluation. However, when these US-guided FNAs were divided further into 2 groups based on the experience of the radiologist performing the FNA, the nondiagnostic rate in the group of experienced radiologists was only 5.4% (or 32 of 592 US-guided FNAs), even though onsite evaluation was not performed. Among radiologists with less experience, adequacy assessment significantly reduced the nondiagnostic rate from 13.0% (22 of 169 FNAs without adequacy assessment) to 4.5% (10 of 220 FNAs with adequacy assessment) (P < 0.01). CONCLUSIONS: The results of the current study demonstrate that onsite adequacy assessment of thyroid FNAs significantly reduces the number of nondiagnostic aspirates. However, the benefit of onsite evaluation, at least for US-guided FNAs, depends on the experience of the radiologist. In the current study, experienced radiologists with a relatively low nondiagnostic rate did not benefit from onsite adequacy assessment. This finding confirms the importance of experience in the performance of FNA, but suggests that onsite adequacy assessment may assist the less experienced operator.