Differential Diagnosis of Periportal Adenopathy Based on Endoscopic Ultrasound Guided Fine Needle Aspiration (EUS-FNA)

Introduction/Objective

Endoscopic ultrasound guided fine-needle aspiration is a safe and accurate diagnostic procedure for abdominal lymphadenopathy. Goal of this study is to evaluate the utility of EUS-FNA in two groups of patients with periportal lymphadenopathy: group 1 with diagnosis of malignancy and group 2 with no known malignant diagnosis.

Methods/Case Report

This is a retrospective study of 74 patients in our database with enlarged periportal lymph nodes detected on cross sectional imaging of the abdomen. All patients underwent EUS-FNA with 22-gauge needle. Three passes were performed for each lymph node detected. Median size of periportal lymph nodes was 19.8 mm (ranging from 5 to 59 mm). 2 groups were compared: group 1 with known malignancy and group 2 with no known malignancy. All patients were clinically followed 6-12month from the procedure.

Results (if a Case Study enter NA)

25 of the 74 (34%) patients had malignant diagnosis. The types of neoplasia detected were lymphoma (3), metastatic adenocarcinoma (16), metastatic acinar cell carcinoma (1) and metastatic neuroendocrine tumor (5). 42 of 74 patients (57%) had negative fine-needle aspiration diagnosis: 40 patients had reactive lymph node diagnosis, 2 patients had granulomatous inflammation diagnosis. 2(1%) of 74 cases had atypical diagnosis, 5(7%) cases were unsatisfactory due to inadequate material obtained during procedure. Sensitivity of the procedure is 45.8% and, specificity is 100%. Positive predictive value (PPV) is 100% and negative predictive value (NPV) is 78.7%. EUS-FNA can detect positive lymph nodes as small as 1 cm, however, this method can also miss positive lymph nodes up to size of 3.5 cm which probably due to the uneven involving of the nodes by tumor cells. Lymph nodes 3.5cm and larger are more likely to be malignant, however in differential diagnosis of small lymph nodes (1 cm in length) they were noT statistically significant difference between the pathologic and benign lymph nodes.

Conclusion

EUS-FNA is effective method for investigating periportal lymphadenopathy with known or unknown malignancy.

PD-L1 Expression in Sarcomas: An Immunohistochemical Study

Introduction/Objective

Immunotherapy is increasingly used for the treatment of metastatic melanoma and carcinomas. PD-I (programmed death 1) and its associated ligand (PD-L1) inhibits the activation of T lymphocytes. This inhibition can be impacted by a number of drugs. Response to these drugs is predicted by assessment of PD-L1 expression. PD-L1 expression varies between 19% and 92% in melanomas and carcinomas. PD-L1 expression is less well documented for sarcomas.

Methods

Fifty-one sarcomas of various histopathologic types were immunohistochemically stained (IHC) for PD-L1 using the antibody clone SP263 (Ventana, Tuscan, AZ). Membrane staining of tumor cells was quantitated as a percentage of total tumor cells. Sarcomas were judged as non-expressors (less than 1%) low-expressors (1 to 50%) and high expressors (greater than 50%). The percentage of each type of sarcoma judged as an expressor was determined.

Results

The percentage of each type of sarcoma expressing PD-L1 is reported and 20% of sarcomas expressed PD- L1. The percentage of sarcomas expressing PD-L1 varied significantly between types but the majority of sarcomas were non-expressors.

Conclusion

PD-L1 IHC expression is valuable in predicting response to immune-modulating drugs. Such therapies may be useful for treatment of metastatic sarcomas. Expression of PD-L1 in carcinomas and melanomas is variable ranging from 19% to 92%. In our study, a minority (20%) of sarcomas expressed PD-L1. Other studies have shown similar results with between 1.4 and 59% (average 24%) of sarcomas expressing PD-L1. Expression appears to be type specific. These finding suggest that PD-L1 based therapy may be less useful in sarcomas than in other malignancies.

Afirma Testing in Thyroid Nodules with Indeterminate Cytology: A single Medical Institute Experience

Introduction/Objective

About 10 to 30% of thyroid fine needle aspiration (FNA) nodules have indeterminate cytology, including Bethesda III, IV, and V. Afirma Gene Expression Classifier (GEC) measuring the expression of 167 mRNA was designed to classify the indeterminate thyroid nodules into benign and suspicious categories. This study aimed to evaluate the clinical performance of the Afirma GEC testing in these indeterminate thyroid lesions.

Methods

Medical records of patients with indeterminate thyroid FNA results and corresponding Afirma GEC results from November 2012 to December 2019 were retrieved. Subsequent surgical follow-up results were obtained. GEC results were compared to the histologic diagnoses.

Results

1. There were 77 cases with indeterminate thyroid FNA results. Cytology diagnosis included 67 Bethesda III and 10 Bethesda IV. Afirma GEC results were benign for 41 cases (53%), suspicious for 32 cases (42%), and non- diagnostic for 4 cases (5%). Twenty seven of 32 cases (84%) with suspicious GEC results had surgical follow-up which revealed 12 malignant and 15 benign histologic diagnoses. Only 11 of 41 cases (27%) with benign GEC results had surgery which showed 8 benign and 3 malignant diagnoses. Based on the data, the sensitivity of this test is 80% and specificity is 65%. Positive predictive value (PPV) is 44% and negative predictive value (NPV) is 73%.

The false positive cases include 5 Hurthle cell adenoma, 4 nodular hyperplasia, 3 follicular adenoma, 2 Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFPT), and 1 lymphocytic thyroiditis. The false negative cases include 2 minimally invasive follicular carcinoma (from same patient) and 1 papillary thyroid carcinoma.

Conclusion

1. We demonstrated in this study that a little more than half of the cases with indeterminate thyroid cytology had negative Afirma GEC results.

2.Afirma test has relatively low specificity (65%) and PPV (44%). The sensitivity (80%) and NPV (73%) is relatively higher but is lower than the values in most literature. This could be due to the fact that majority of the Afirma GEC negative cases in this study did not have surgical follow-up and the sample size is small.

3.Afirma GEC test is a relatively good “rule-out” molecular test for indeterminate thyroid nodules but is not a reliable “rule-in” test due to the low specificity and PPV.

Assessment of the biocompatibility of two novel, bionanocomposite scaffolds in a rodent model

Two novel, bionanocomposite scaffolds were evaluated in a rodent model over the course of three months to determine whether these scaffolds possessed adequate biocompatibility characteristics to warrant further evaluation as possible tissue reconstruction scaffolds. These bionanocomposite scaffolds were comprised of amine-functionalized gold nanoparticles (AuNP) or silicon carbide nanowires (SiCNW) crosslinked to an acellular porcine diaphragm tendon. It was hypothesized that the addition of nanomaterials to the porcine tendon would also improve its biocompatibility by imparting a nanostructured surface. As early as seven days after implantation, both types of bionanocomposite scaffolds displayed evidence of granulation tissue and the beginning of scaffold remodeling with new collagen deposited by the host, and by ninety-seven days the bionanocomposite scaffolds were completely remodeled with no evidence of any adverse host tissue reaction or scar tissue formation. The AuNP bionanocomposite scaffolds exhibited accelerated scaffold remodeling compared to the SiCNW scaffolds.