Usefulness of Immunohistochemical and Histochemical Studies in the Classification of Lung Adenocarcinoma and Squamous Cell Carcinoma in Cytologic Specimens

Abstract

Histologic subtyping of non-small cell lung carcinoma (NSCLC) is important because the efficacy of new treatments depends on tumor histologic features. We assessed the diagnostic accuracy of classification of lung adenocarcinoma and squamous cell carcinoma (SCC) on cytologic and biopsy specimens based on cytomorphologic studies alone or in combination with ancillary studies compared with resection specimens. Compared with adenocarcinoma, the diagnosis of SCC was based more often on cytomorphologic studies alone (139/185 [75.1%] vs 107/263 [40.7%]). Significantly increased use of immunohistochemical studies in cytology was noted after introduction of targeted lung carcinoma therapies (22/156 [14.1%] for adenocarcinoma and 5/46 [11%] for SCC from 2000-2004 vs 134/156 [85.9%] for adenocarcinoma and 41/46 [89%] for SCC from 2005-2010). Use of immunohistochemical studies resulted in increased diagnostic accuracy for adenocarcinoma (56% [44/78] from 2000-2004 vs 83.2% [154/185] after 2005) but not for SCC (77% [57/74] before 2004 vs 73.9% [82/111] from 2005-2010). Adenocarcinoma showed high expression of cytokeratin (CK)7 (146/146 [100%]), thyroid transcription factor-1 (131/152 [86.2%]), surfactant A (29/36 [81%]), and periodic acid-Schiff with diastase (69/86 [80%]). All SCCs were positive for CK5/6 and p63. Use of immunohistochemical studies on cytologic cell blocks may improve classification of NSCLC.

Mucin Production Correlates with Dual Expression of Epidermal Growth Factor Receptor and Its Ligand the Epidermal Growth Factor in Non-Small Cell Lung Cancer

“…In the present study, the mucin production was mostly evidenced in adenocarcinomas as compared with the rest of lung tumors, similar to previous reports [22,27,28]. Interestingly, the presence of mucin was signifi cantly higher in NSCLC samples displaying increased degree of cytological atypia.…”

Immunohistochemical Profile of Lung Tumors in Image Guided Biopsies

“…Both HMWK and P63 are useful to differentiate SCC from adenocarcinoma and poorly differentiated SCC from SCLC and large cell neuroendocrine carcinoma. [9] In our study, out of 20 cases reported as SCC and 4 cases as NSCLC in H&E, HMWCK was expressed in 20 cases (sensitivity 83.3%) ( fig.1) and P63 showed immunopositivity in 22 cases (sensitivity 91.7%) ( fig.2). P63 was not expressed in any of the adenocarcinoma cases with 100% specificity.…”

“…[10] In a study by R.Ocque, N.Tochigi et al, 2011, P63 expression was found in all the 30 cases of SCCs with 100% sensitivity. [9] Recent studies have proposed a panel of markers for pulmonary adenocarcinomas-CK-7, CK-20, TTF-1. Primary lung adenocarcinoma shows strong and diffuse positivity with CK-7.…”

Pseudomesotelomatous Adenocarcinoma with Three Cases

“…VATS is often required toget a sample of the size that is suitable for definite diagnosis [7]. Histomorphological, histochemical and immunohistochemical findings should be evaluated together for the definitive diagnosis of pseudomesotelomatic adenocarcinoma.The specificity of TTF-1, CEA and CD15 as the most useful markers in patients with adenocarcinoma is respectively 100%, 97-98.8%, 93% and 67%.…”