Excuse Me...There Aren't Supposed to be That Many Mast Cells in a Lymph Node

Check out this scary lymph node cytology!

This is an FNA from a regional lymph node in a dog that had a nearby mast cell tumor. The vet aspirated the node to check for metastases....and metastases they found...

This thing is being completely overtaken by variably granulated, neoplastic mast cells (red arrows). The poor little lymphocytes (green arrows), which are of course the normal inhabitants of a lymph node, are being crowded out with nowhere to go.

I can't really think of a peppy way to end this post, it's kind of a beautiful bummer of a case, huh? If Pathology were a band I think that'd be a good band name. "Beautiful Bummer".