What is the next stain to use if granules do not stain with aqueous quick stain in a suspected mast cell tumor?

When dealing with suspected mast cell tumors and using the aqueous quick stain, the staining properties of mast cell granules can sometimes lead to inconclusive results. If the granules do not stain well with this initial method, the Giemsa stain is the next appropriate choice because it is specifically designed to highlight cellular components and granules more effectively.

Giemsa stain is known for its ability to stain basophilic cells and their granules, making it particularly useful for identifying mast cells, which are characterized by numerous granules containing heparin and histamine. With Giemsa, the granules can take on a different color, allowing for better visualization and assisting in confirming a diagnosis of mast cell tumors.

Other stains may not provide the same level of detail regarding granules as Giemsa, leading to difficulties in proper identification. Hence, utilizing Giemsa helps ensure a more accurate analysis in the context of this type of tumor.