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Villous adenoma and urothelial carcinoma with villoglandular differentiation (UCVGD) are rare urothelial tumours showing villous morphology, the former being a preneoplastic entity and the latter being a malignant one. The detailed immunohistochemistry of these entities is previously not described in the literature. Moreover, a limited biopsy sample of UCVGD or a villous adenoma with or without adenocarcinoma may be difficult to distinguish on the basis of the histomorphology alone. An immunohistochemical panel comprising of GATA3, p63, β‐catenin, CK7 and CK20 was performed on five cases of UCVGD and three cases of villous adenoma with the aim of studying the expression of the proteins thereby aiding in the diagnosis of these entities in a limited surgical pathology specimen. The mean age of UCVGD was 66.8 years and all the patients were male. All the cases of UCVGD were associated with high grade papillary urothelial carcinoma with lamina propria invasion. The immunohistochemical panel showed strong nuclear GATA3 expression in the urothelial component of UCVGD. Interestingly, the high grade and the low grade villoglandular components of UCVGD also expressed GATA3 (nuclear) with a progressive loss of expression from the high grade to the low grade component. The villous adenomas showed negativity or aberrant cytoplasmic positivity for GATA3. The β‐catenin showed a gradual loss of membranous expression from villous adenoma to low grade and high grade villoglandular components of UCVGD with a patchy membranous expression in the urothelial component of the UCVGD. p63 showed strong nuclear positivity in the urothelial component and uniform negativity in the villous adenoma and villoglandular component of UCVGD irrespective of its grade, thereby distinguishing the villoglandular component from the urothelial component. The urothelial component of UCVGD showed strong membranous CK7 expression and was higher than the CK20 expression in the urothelial component. In contrast, CK20 expression was higher in villous adenoma as compared to CK7. There was no difference in the expression of CK7 and CK20 in the villoglandular components and low grade and high grade villoglandular areas. The above‐mentioned immunohistochemical pattern may help to distinguish the UCVGD from the villous adenoma. [ABSTRACT FROM AUTHOR]

ALK gene rearrangement in the lung adenocarcinomas is the second most common (1.6-11.7% of NSCLC) targetable genomic change after EGFR mutations. However, the prevalence and clinicopathological features of ALK-rearranged lung adenocarcinomas from North India are lacking. A total of 240 cases of lung adenocarcinoma were screened for EGFR mutations and for ALK expression. Smoking status, TNM stage, and treatment response were recorded in all cases. Out of 240 cases screened, 37 cases were positive for EGFR mutations and 17 cases (7.08%) showed ALK positivity with immunohistochemistry and break-apart FISH. On excluding 37 EGFR mutation-positive cases, the incidence of ALK-positive adenocarcinoma appears to be higher (17/203 cases, 8.03%). Eight were men and nine were women with mean age of 51.7 years. Majority (62.5%) were non-smokers and had unresectable disease (70.6% stage IV, 17.6% IIIB). The morphological patterns noted were solid (12 cases), papillary (four cases), and micropapillary (one case). Signet ring (two cases) and clear cell change (one cases) were noted. Out of five patients who received crizotinib, three had partial response and two had stable disease. ALK-rearranged lung adenocarcinomas account for a minor proportion of NSCLC with prevalence similar to that reported in literature. However, as contrast to published data in our series, patients were in older age group and had solid and papillary pattern on morphology with an aggressive course. [ABSTRACT FROM AUTHOR]