Electron acoustic waves are found to be susceptible to various structure formation. Distinct appearance of structures depend on parameter space. We have shown that weakly nonlinear electron acoustic wave in presence of an external uniform weak magnetic field is governed by a generalized three-dimensional Korteweg-de Vries equation. The Painlevé analysis shows that this equation is conditionally integrable. Exact solutions with the help of Bäcklund transformation reveal that the nonlinear electron acoustic wave does support breather, bursts, soliton and periodic structures. The results are discussed in the context of experiments and observations. © 2020 IOP Publishing Ltd.