Nuclear Morphological and Morphometric Features of Reactive versus Neoplastic Gastric Mucosa

Introduction: Gastric carcinoma is the second most common tumor in the world. Highest incidence is found in Japan, Chile and Italy. In tumor progression model of intestinal type of gastric carcinoma, the cellular changes progress from initial inflammation and chronic gastritis to metaplasia, dysplasia and adenocarcinoma. Distinguishing regenerative atypia from dysplasia and carcinoma is the most daunting challenge for a pathologist. Focusing on cytological especially nuclear features can provide an opportunity for early diagnosis and may improve patient’s survival. Aim: The aim of this study was to compare the nuclear morphological and morphometric features of regenerative atypia, dysplasia and intestinal type of gastric adenocarcinoma and to identify the features potentially useful in diagnosing infiltrating carcinoma on nuclear changes. Material and Methods: 50 gastric endoscopic biopsies or gastric resection specimens were evaluated at the Pathology Department Pakistan Institute of Medical Sciences between January 2008 and October 2009. The specimens were grouped as normal, reactive atypia, dysplasia and carcinoma. Using oil immersion microscopy, we studied nuclear features like number and location of nuclei (basal, mid or apical part of cell), nuclear size (area, major axis length and minor axis length), anisonucleosis, poikilonucleosis, nuclear/cytoplasmic (N/C) ratio (low, normal, or increased), chromatin (hyperchromaticity, chromatin distribution, chromatin quality), number of nucleoli, presence of bizarre nuclei, nuclear membrane folds and breaks, presence and location of mitoses and atypical mitoses. Morphometric measurement of nuclear area, major axis length and minor axis was done in each case. Results: Marked nuclear enlargement and pleomorphism, frequent prominent nucleoli, irregularly thickened nuclear membranes with frequent folds and breaks, irregularly distributed clumpy chromatin, bizarre nuclei and high mitotic count especially atypical mitoses favour malignancy whereas mild nuclear enlargement and pleomorphism, occasional prominent nucleoli, regular nuclear membranes, uniform chromatin distribution and few mitotic figures are indicative of regenerative atypia. Mean nuclear area, major and minor axis length increase in a step ladder pattern in order of normal control, reactive atypia, dysplasia and carcinoma. Conclusions: Nuclear or cytological classification schemes can be useful in early diagnosis of gastric carcinoma. Further research studies with long term follow up of the patients should be done.