NSE , CEA ,Calcitonin immunohistochemical stains are typically positive, and synaptophysin and chromogranin should be added
to that list as well. Interestingly, chromogranin is both more specific and more sensitive than calcitonin (the small
cell variant, in particular, can be negative for calcitonin, but amyloid is typically positive). Virtually all tumors are
positive for CEA and serum levels can also be elevated and used as a marker to follow for disease recurrence. 80%
of tumors are also positive for bcl-2.