Table 2 Mastocytosis types and subtypes.

From: The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms

Cutaneous mastocytosis

  Urticaria pigmentosa/Maculopapular cutaneous mastocytosis

   Monomorphic

   Polymorphic

  Diffuse cutaneous mastocytosis

  Cutaneous mastocytoma

   Isolated mastocytoma

   Multilocalized mastocytoma

Systemic mastocytosis

  Bone marrow mastocytosis

  Indolent systemic mastocytosis

  Smoldering systemic mastocytosis

  Aggressive systemic mastocytosis

  Systemic mastocytosis with an associated haematologic neoplasm

  Mast cell leukemia

Mast cell sarcoma

  1. Note: Well-differentiated systemic mastocytosis (WDSM) represents a morphologic variant that may occur in any SM type/subtype, including mast cell leukaemia.