How does Dostoevsky's "Notes from the Underground read as 'Realism' and 'Existentialism'

Choose a specific aspect or passage of Dostoevsky's Notes from the Underground and read it as both a novel of realism and a novel of Existentialism.

This is NOT a research paper. It should be based primarily on close textual readings. Specific Examples and extended discussion/analysis. MLA Format expected. 4-5 pages and will be considered 15% of my final grade.