What histological feature is commonly found in a granuloma of a patient with sarcoidosis?

The histological feature that is commonly found in a granuloma of a patient with sarcoidosis is epithelioid cells. These cells are modified macrophages that take on an epithelial appearance and play a central role in the formation of granulomas. In sarcoidosis, these epithelioid cells cluster together within the granuloma and form a distinctive structure that is a hallmark of this condition.

Asteroid bodies, although they can be associated with sarcoidosis, are not universally present in all cases. These are star-shaped inclusions that can be seen in multinucleated giant cells, but their presence is not definitive in diagnosing sarcoidosis. Similarly, while multinucleated giant cells may be present in sarcoid granulomas, they are not a defining feature unique to the disease, as such cells can appear in granulomas from various causes. Granulation tissue, on the other hand, is a part of the healing process following injury or inflammation but is not characteristic of the non-caseating granulomas seen in sarcoidosis.

Thus, epithelioid cells serve as the primary histological marker distinguishing sarcoidosis from other granulomatous diseases, helping pathologists make an accurate diagnosis.