Increased CD25+ mast cell proportion

What it means

An increased proportion of mast cells are positive for the cell surface marker CD25 (also called interleukin-2 receptor alpha chain).

Mast cells do not normally express CD25, but neoplastic mast cells may be CD25-positive. Aberrant expression of CD2 and/or CD25 by bone marrow, peripheral blood or other extracutaneous tissue mast cells is currently used as a minor World Health Organization diagnostic criterion for systemic mastocytosis. CD25 expression alone presented a similar sensitivity (100%) with a slightly higher specificity (99.2%).

Rare diseases that can present with this3

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category