There are still those, who take themselves to be "Marxians", but who deny that dialectic played any central part in the mature theory-making work of Karl Marx.
The following quotation, which, according to Peter Hudis, Marx penned in 1875, as part of a passage for volume II of <<Das Kapital>> -- one that Engels left out of the published version -- is but one of many that should have decided us, long since, on the validity -- or on the lack thereof -- of such denials --
"In my zealous devotion to the schema of Hegelian logic, I even discovered the Hegelian forms of the syllogism in the process of circulation. My relationship with Hegel is very simple. I am a disciple of Hegel, and the presumptuous chattering of the epigones who think they have buried this great thinker appear frankly ridiculous to me."
[Quoted in Peter Hubis, Marx's Concept of the Alternative to Capitalism, Haymarket Books, Chicago, IL, 2013, p. 5, footnote 7, from Karl Marx, "Manuscripte zum zweiten Buch des "Kapitals" 1868 bis 1881", edited by Teinosuko Otani, Ljudmila Vasina and Carl-Ewrich Mori in Marx-Engels Gesamtausgabe II/11, Berlin: Akademie Verlag.].