King Hussein died of non-Hodgkin's lymphoma. What is non-Hodgkin's lymphoma and is there a Hodgkin's lymphoma? Lymphomas are cancers of the lymphatic system. There's a Hodgkin's disease, named after Thomas Hodgkin of London, who first described it in 1832. And there are a number of other forms, grouped under the umbrella name of non-Hodgkin's lymphoma.
King Hussein's cancer was believed to be the most common type of the latter group, known as B cell non-Hodgkin's lymphoma.