<i><scp>MAP2K1</scp>‐</i>driven mixed Langerhans cell histiocytosis, Rosai‐Dorfman‐Destombes disease and Erdheim‐Chester disease, clonally related to acute myeloid leukemia
Arturo Bonometti, Giuseppina Ferrario, Antonina Parafioriti, Demostene Giardino, Federico Simonetti, Alessandro Ginori, Emanuela Passoni, Emilio Berti, for AIRI, Associazione Italiana Ricerca Istiocitosi ONLUS
Abstract
Mixed histiocytoses are a rare and recently recognized subset of histiocytic disorders that may involve the skin, characterized by the synchronous or metachronous development of lesions with Langerhans and/or non-Langerhans cell histiocytosis histopathological features. Around 10% of patients diagnosed with histiocytosis may develop a hematological malignancy, often with dramatic prognostic consequences. We hereby describe the exceptional case of a patient developing a MAP2K1-driven mixed histiocytosis with Langerhans cell histiocytosis, Rosai-Dorfman-Destombes disease, and Erdheim-Chester disease features and cutaneous involvement, progressing to a fatal and clonally-related acute myeloid leukemia. We reviewed the literature on similar cases and discussed the histopathological difficulties in their diagnosis and their clinical-pathological features.