P3.01-011 Clinocopathological Profile and Role of Immunohistochemistry in the Diagnosis of Primary Lung Cancer - A Prospective Study from Eastern India: Topic: Morphology

Abstract

Listen

Translate article

The clinico-pathological profile of lung cancer has changed considerably over the time in India. The histologic type also has changed from a predominant squamous histology to adenocarcinoma. We performed a prospective evaluation of primary lung cancers (PLCs) on the basis of clinical characteristics, histopathology and immunohistochemistry (IHC). The clinicohistopathological features and IHC characteristics of all PLCs(as per 2015 WHO classification) were described prospectively over a period of two years (2014-2016).The antibodies that were used were TTF-1, napsin A, P40, CK7, CK20, vimentin, synaptophysin, chromogranin, BCL-2, CD34, LCA, CD99, AFP & βHCG. We have studied 140 PLCs (78.6% male and 21.4% females) with age ranging from 25 to 85 years. Most common symptoms were cough and chest pain observed in 65% of our cases. In 14.2% cases the patients primarily presented with metastasis. The most common site was brain (40%), cervical nodes (45%) and skin (15%) in our record. There were 84cases of NSCLC and 5 cases of small cell carcinoma. 95.2% of NSCC could be further classified with the help of TTF-1,napsin A, CK7 & P40 into adenocarcinoma (71.4%), 23.8% cases of squamous cell carcinoma, and 4.8% of cases could not be subtyped further. TTF-1 was seen in all the cases of adenocarcinoma, whereas p40 was seen in all the cases of squamous cell carcinoma. Only in 4.8% of cases neither the morphology nor the staining pattern supported adenocarcinoma or squamous and hence was diagnosed as NSCC-NOS. In addition to these usual types, other unusual morphological variants seen were3 cases each of carcinoid, large cell neuroendocrine carcinoma, & synovial sarcoma. There were also few rarer ones such as lymphoepithelioma like carcinoma, choriocarcinoma and yolk sac tumor. In 39 cases the biopsy was inadequate and hence could not be opined. Accurate categorization of primary lung tumors, has both therapeutic and prognostic significance. TTF1 and P40 are very sensitive markers for differentiating adenocarcinoma and squamous cell carcinoma of the lung. Addition of napsin A contributes to a higher sensitivity for adenocarcinomas.