Ward Reeves

Follicular lesions of the thyroid: A retrospective study of 1,348 fine needle aspiration biopsies

Fine needle aspiration (FNA) has proven to be an effective tool in management of patients with thyroid nodules. However, the diagnosis of follicular patterned lesions can be challenging. The surgical and cytopathology computer database at a large referral medical center was searched for cases that had both cytologic and histologic thyroid accessions from January 2004 to November 2008. A total of 1,255 histologic thyroid specimens and 2,776 thyroid FNA biopsies were retrieved for review. Histologically, 272 overt malignancies were identified; 20 (7.4%) were follicular carcinomas. Cytologically, 1,348 cases were follicular‐patterned lesions, comprising 1,044 cases of “benign follicular nodules” (BFN), 137 cases of “follicular lesions of undetermined significance” (FLUS), and 167 cases of “suspicious for follicular neoplasm” (SFN). Seventy‐nine (7.5%) of BFN, 23 (16.8%) of FLUS, and 65 (38.9%) of SFN cases had histologic follow‐up. Overt malignancy, a cystic papillary carcinoma, was identified histologically in only one case of BFN, for a negative predictive value of 98.7%. Overt malignancy was identified histologically in two cases of FLUS, both follicular variant of papillary carcinoma, for a positive predictive value of 8.7%. Overt malignancy was identified histologically in 14 cases of SFN, for a positive predictive value of 21.5%. Five follicular carcinomas were identified histologically in the SFN category, all minimally invasive. Incidental (“occult”) papillary microcarcinoma were identified histologically in all three categories. In this study, the risk of overt malignancy increases from 1.3%, to 8.7%, to 21.5% for BFN, FLUS, and SFN, respectively. All follicular carcinomas identified histologically occurred in the SFN category and all were minimally invasive. Papillary microcarcinomas can occur in any of the three diagnostic categories. Diagn. Cytopathol. 2012;40:E8–E12.

Immunohistochemical analysis of E‐cadherin and zeste homolog 2 expression in endoscopic ultrasound‐guided fine‐needle aspiration of pancreatic adenocarcinoma

Recent studies have demonstrated that partial or complete loss of E‐cadherin (EC) and nuclear accumulation of zeste homolog 2 (EZH2) are hallmarks of poorly differentiated pancreatic adenocarcinoma (PAC). Depletion of EZH2 sensitizes cancer cells to chemotherapy in vitro. The objective of this study was to determine EC and EZH2 expression by immunohistochemistry (IHC) in samples obtained by endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) as potential biomarkers for treatment and disease prognosis.

Parakeratotic-like cells in effusions — A clue to diagnosis of malignant mesothelioma

Background: Malignant mesothelioma (MM) is an aggressive neoplasm with a poor prognosis. Its incidence has been increasing worldwide. Cytological examination of an effusion is often the first opportunity to diagnose MM. However, the cytological diagnosis of MM can be difficult. We have noticed that parakeratotic-like cells, with orange cytoplasm and pyknotic nuclei, are present in many cases of mesothelioma on Papanicolaou-stained cytology slides. Although this cytological finding has been described previously, to our knowledge, there has been no systematic study of this finding. Our study is to determine whether the presence of small parakeratotic / orangeophilic cells (PK-like cells) is specific for the cytodiagnosis of mesothelioma. Materials and Methods: A total of 90 body fluid cases were selected from our archived specimens in the Cytology Section at the University of Chicago Hospital accessioned between January 2000 to November 2011. They included 30 cases of mesothelioma, 30 cases of adenocarcinoma, and 30 cases of reactive mesothelial cells. Results: PK-like cells were present in 83% of the mesothelioma cases, 13% of the adenocarcinoma cases, and 7% of the reactive cases. Our data showed that the presence of PK-like cells has a specificity of 90%, sensitivity of 83%, positive predictive value of 81%, and negative predictive value of 84% for the diagnosis of malignant mesothelioma in body cavity fluids. Conclusion: The presence of PK-like cells in the effusion specimen, especially in pleural effusions, is a highly specific and moderately sensitive cytological feature for diagnosis of mesothelioma.