p40 Immunohistochemistry Is an Excellent Marker in Primary Lung Squamous Cell Carcinoma

BACKGROUND: Lung cancer is the third most common cancer worldwide. With major advances in the molecular testing of lung cancers and the introduction of targeted therapies, the distinction between adenocarcinoma and squamous cell carcinoma as well as pathologic subtyping has become important. Recent studies showed that p40 is highly specific for squamous and basal cells and is superior to p63 for diagnosing lung squamous cell carcinoma. The aim of this study was to evaluate the use of p40 immunohistochemical stain in the diagnosis of non-small cell lung carcinoma and its potential to replace current p63 antibody as the best immunohistochemical squamous marker. METHODS: Seventy formalin-fixed paraffin-embedded cases previously diagnosed as primary lung squamous cell carcinoma (n = 35) and lung adenocarcinoma (n = 35) from January 2008 to December 2016 were retrieved. The results of tumour cell immunoreactivity for p40 and p63 antibodies in lung squamous cell carcinoma and lung adenocarcinoma were compared. RESULTS: p40 was expressed in 27 cases of lung squamous cell carcinoma (77.1%). All cases of lung adenocarcinoma (35/35, 100%) were negative for p40. p63 expression was positive in 30 cases of lung squamous cell carcinoma (85.7%) and 13 cases of lung adenocarcinoma (37.1%). Reactivity for both p40 and p63 in lung squamous cell carcinoma was strong and diffuse, whereas variable reactivity was observed in lung adenocarcinoma. CONCLUSIONS: p40 is an excellent marker for distinguishing lung squamous cell carcinoma from adenocarcinoma, and p40 expression is equivalent to p63 expression in lung squamous cell carcinoma.

Hurthle cells in fine needle aspiration cytology of the thyroid: a potential diagnostic dilemma?

Hurthle cells are not uncommonly encountered in thyroid fine needle aspiration cytology (FNAC) smears. They are easily recognized by their distinct cytomorphology in cytological preparations, i.e. large, polygonal cells displaying uniform, rounded nuclei, often prominent nucleoli and abundant granular cytoplasm. Hurthle cells can be seen in both non-neoplastic and neoplastic thyroid lesions which can pose diagnostic dilemma to cytopathologists, especially when the lesions are focally sampled. We describe a case of solitary thyroid nodule in a 46-year-old male, whose aspirates comprised predominantly of Hurthle cells exhibiting nuclear features suspicious of papillary carcinoma, which turned out to be Hurthle cell carcinoma on subsequent histological sections. The potential diagnostic pitfalls of Hurthle cell lesions and associated conditions in thyroid FNA are discussed. The presence of Hurthle cell change in a wide variety of thyroid lesions can be diagnostically challenging. However, accurate diagnosis can still be made with careful observation of the predominant cell population, nuclear features and whether there is abundant colloid or lymphocytes in the background.

Identification of Y Chromosomal Material in Turner Syndrome by Fluorescence In Situ Hybridisation (FISH)

Turner syndrome is one of the most common chromosomal abnormalities affecting newborn females. More than half of patients with Turner syndrome have a 45X karyotype. The rest of the patients may have structurally abnormal sex chromosomes or are mosaics with normal or abnormal sex chromosomes. Mosaicism with a second X sex chromosome is not usually of clinical significance. However, Turner syndrome patients having a second Y chromosome or Y chromosomal material are at risk of developing gonadoblastoma later in life. The aim of this study is to compare the results of conventional (karyotyping) and molecular cytogenetics (FISH), and discuss the advantages and limitations in the diagnosis of Turner syndrome. We also aim to compare the degree of mosaicism identified using conventional cytogenetics and FISH techniques. Conventional cytogenetics and FISH analyses were performed on eight peripheral blood samples of patients with Turner syndrome collected between 2004 and 2006. From this study, two out of eight patients with Turner syndrome were found to have the sex determining region on the Y chromosome (SRY) gene by FISH analysis. Our results showed that the rate of detection of mosaic cases in Turner syndrome was also increased to 88% after using the FISH technique. We concluded that FISH is more superior to conventional cytogenetics in the detection of the Y chromosomal material. FISH is also a quick and cost effective method in diagnosing Turner syndrome and assessing the degree of mosaicism.