I think this is what you are asking for (i.e., delete all rows that have equal neighbors in column 10):
X = your matrix
n = 10; % the column to use for the comparison
d = diff(X(:,n)); % the 0's in d indicate where neighbors are equal to each other
d = [d;1] .* [1;d]; % vector that has 0's for all rows that are equal to neighbors
X(~d,:) = []; % delete the rows that have equal neighbors using logical indexing
