Rheumatologists are often consulted regarding both typical and atypical vasculitides, vasculopathies, and hypercoagulability. It is important to keep in mind that all of these can come from neoplastic or paraneoplastic causes. In these cases, the treatment must focus on treating the underlying malignancy rather than aggressive immunosuppression. This article focuses on reported cases, pathophysiologic mechanisms, and lessons that can be learned from the literature regarding neoplastic and paraneoplastic vasculitides, vasculopathies, and hypercoagulability.