label: Smouldering systemic mastocytosis
label_lc: smouldering systemic mastocytosis
description: "Smouldering systemic mastocytosis is a type of systemic mastocytosis (SM). This clonal hematologic disease, with a slow progression, results in an accumulation of neoplastic mast cells in the visceral organs over time and patients present with splenomegaly, hypercellular marrow and, in some cases, urticaria pigmentosa-like skin lesions."