When my reflux escalated to the "next stage" in May of '10, I had such a lump. (The medical term is Cricopharyngeus Spasm.) It was continuous, and lasted until October '10 when I tried my first course of PPI treatment with omeprazole. I could only stand the omeprazole for 14 days because of massive headache, but the spasm finally disappeared.
Now one of my persistent LPR symptoms is general dysphagia, similar, but not quite as uncomfortable.
If you've already been diagnosed with GERD, then the presence of the spasm you noted is an important clue to indicate that you also may have LPR. This has relevance in diagnosis, and possible treatment options and expectations.