Cytohistopathological Association and the Use of a Dual Immunohistochemical Regimen in the Diagnosis of Lung Malignancies: A Cross-sectional Study
Introduction: Lung cancer is a highly aggressive malignancy that causes significant morbidity and mortality. The incidence of lung cancer has been increasing in the past few decades. Cytology aids in the initial evaluation and diagnosis of patients with lung cancer. Currently, the classification...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
JCDR Research and Publications Private Limited
2023-10-01
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Series: | Journal of Clinical and Diagnostic Research |
Subjects: | |
Online Access: | https://www.jcdr.net/articles/PDF/18596/63762_CE[Ra1]_F(SS)_QC(KK_IS)_PF1(AP_SS)_PFA_NC(AP_KM)_PN(KM).pdf |
Summary: | Introduction: Lung cancer is a highly aggressive malignancy
that causes significant morbidity and mortality. The incidence
of lung cancer has been increasing in the past few decades.
Cytology aids in the initial evaluation and diagnosis of patients
with lung cancer. Currently, the classification of lung carcinoma
has expanded beyond small cell lung carcinoma and Non-Small
Cell Lung Carcinoma (NSCLC). Precise subtyping of poorly
differentiated NSCLC into adenocarcinoma and Squamous Cell
Carcinoma (SCC) has a direct impact on patient management
and prognosis. The morphologic diagnosis forms the basis and
is further supplemented by a panel of immunohistochemical
markers. Immunohistochemistry (IHC) is important in cases
with poorly differentiated morphology or partial sampling. The
IHC panel used includes Tumour Protein p63 (p63) and Thyroid
Transcription Factor (TTF1) for subtyping lung cancer.
Aim: The present study was conducted with the aim of
studying the age and gender distribution, risk factors,
cytohistopathological association, and formulating an effective
IHC panel for the precise yet effective subtyping of poorly
differentiated lung malignancies.
Materials and Methods: This cross-sectional study included
cases retrieved from the Archives of Pathology Department,
SRM Medical College and Research Centre, Chennai, Tamil
Nadu, India, between July 2012 and July 2016. The cases
included had a diagnosis of lung malignancy (confirmed by
cytology/biopsy) or were suspected of having malignancy
based on clinical/radiological findings. The study period was
from July 2015 to August 2016. The cytology and biopsy slides
were reviewed, and the malignancy was classified according
to the World Health Organisation (WHO) classification of lung
malignancies (2021). IHC was performed on the cases using
the markers p63 and TTF1 as a dual regimen. Diagnosis and
subtyping of tumours were done based on histomorphology,
and the tumours were reclassified based on IHC findings. The
data were statistically analysed using SPSS software version 25
and the ROC curve.
Results: The mean age of the patients was 60.9 years. The
study included a total of 50 cases of lung carcinoma, with
an average age of 60.9 years (ranging from 30 to 88 years).
Among the cases, 35 (70%) had a positive smoking history. A
concordant cytohistopathological association was observed
in 26 (52%) of cases. Adenocarcinoma was the predominant
subtype, accounting for 21 (42%) of cases. Tumour cells in
adenocarcinoma showed positive staining for TTF-1, with
the marker exhibiting 100% sensitivity and 83% specificity.
In SCC, tumour cells were positive for p63, with the marker
demonstrating 92% sensitivity and 82% specificity. Both
markers showed effective sensitivity and specificity when used
as a dual regimen.
Conclusion: Although lung cancer is typically diagnosed in the
elderly population, there has been an increase in cases among
younger individuals due to urbanisation. Smoking remains an
important risk factor for lung malignancy. Exfoliative cytology
alone is not sufficient for the diagnosis of lung malignancies
and should be supplemented with biopsy for more accurate
results. Adenocarcinoma was found to be the most common
subtype in our study. The IHC panel of p63 and TTF-1 proved
to be an effective regimen for classifying poorly differentiated
lung carcinomas.
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ISSN: | 2249-782X 0973-709X |