This evening I discovered that the newest leaves on one of the main stems of a Brandywine tomato plant had dark brow speckles and blotches. Some had turned almost fully brown and crunchy. The rest of the plant looks healthy, save for some curling of the oldest leaves. The foliage is dark green and perky. The fruit are small and don't appear to have any problems, and only the stem of the worst leaf had some brown legions on it. Identification is proving difficult because there hasn't been any yellowing of the leaves or a halo around the spots.
Any ideas what this might be? Do I need to pull out the whole plant? I removed all foliage that had even a hint of freckles forming.