The word, "disease", includes any pathological condition regardless of cause.
I assume that the using both names with Hodgkins Disease and Hodgkins Lymphoma would be a similar thing to using both "Lou Gherig's Disease" and "Amyotrophic lateral sclerosis (ALS)". One name is more of a popular-use name. The other is the medically correct term.
Just to note, there is also "Non-Hodgkins Lymphoma", which is a completely different condition.