Histologically, how are the cells in carcinoid tumors described?

In carcinoid tumors, the cells are characterized histologically as uniform and round. This description reflects the typical appearance of these neuroendocrine neoplasms, which are often derived from enterochromaffin cells in the gastrointestinal tract. The cells tend to be polygonal to round and demonstrate well-defined cytoplasmic borders, often arranged in sheets or trabecular patterns.

The uniformity of the cells is a key feature, contrasting with some other tumor types where cellular atypia might be prominent. Additionally, carcinoid tumors commonly exhibit bright cytoplasmic granules, which may be visualized with special staining techniques such as chromogranin A or synaptophysin. This granularity can sometimes lead to misconceptions in cellular description, but it's the uniform and rounded nature of the cells that is most notable histologically.

In summary, the characteristic uniform and round cell morphology is distinctive to carcinoid tumors and plays a crucial role in their identification through histopathological evaluation.