Olmos Alpiste, FerranSegura Tigell, SoniaTomás-Velázquez, AlejandraAguado, LeyreEspaña, AgustínArriola Aperribay, EdurneMartín-Algarra, SalvadorBarranco Sanz, Luis CarlosLloreta, Josep, 1958-Pujol Vallverdú, Ramon Maria2021-10-222021Olmos-Alpiste F, Segura S, Tomás-Velázquez A, Aguado L, España A, Arriola E, Martín-Algarra S, Barranco C, Lloreta J, Pujol RM. Diffuse dermal mucinosis secondary to colony-stimulating factor 1 receptor monoclonal antibody treatment: A novel and peculiar drug-induced diffuse cutaneous mucinosis. J Dermatol. 2021; 48(3):380-4. DOI: 10.1111/1346-8138.156620385-2407http://hdl.handle.net/10230/48759Colony-stimulating factor 1 receptor (CSF1R) inhibitors represent a new class of immune-modulatory drugs, mostly investigated in clinical trials in different malignant neoplasms. Four patients, diagnosed with recurrent or advanced malignant neoplasm and treated with a combination of anti-programmed death ligand 1 and anti-CSF1R monoclonal antibodies, developed an asymptomatic cutaneous eruption characterized by an ill-defined pseudoedematous to waxy diffuse infiltration with a reticular cobblestone-like pattern. Histopathological examination revealed diffuse mucin deposition involving the superficial and mid-dermis with fragmented and scattered elastic fibers. The exact pathogenic mechanisms implicated in the development of mucin deposits in patients treated with CSF1R inhibitors remain to be elucidated. A reduced degradation and clearance of components of the extracellular matrix by macrophages secondary to CSF1 pathway inhibition may be hypothesized. Shredding and fragmentation of elastic fibers may be a result of the increased accumulation of mucopolysaccharides. This observation illustrates the new spectrum of skin-related toxicities secondary to new targeting therapies. This may contribute to a better understanding of the underlying pathogenic mechanisms in skin diseases characterized by a persistent dermal glycosaminoglycan deposition.application/pdfengThis is the peer reviewed version of the following article: Olmos-Alpiste F, Segura S, Tomás-Velázquez A, Aguado L, España A, Arriola E, Martín-Algarra S, Barranco C, Lloreta J, Pujol RM. Diffuse dermal mucinosis secondary to colony-stimulating factor 1 receptor monoclonal antibody treatment: A novel and peculiar drug-induced diffuse cutaneous mucinosis. J Dermatol. 2021; 48(3):380-4. DOI: 10.1111/1346-8138.15662, which has been published in final form at http://dx.doi.org/10.1111/1346-8138.15662. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1111/1346-8138.15662Anti-programmed death ligand 1Colony-stimulating factor 1 receptor inhibitorDermal mucinosisDrug reactionSkin toxicityinfo:eu-repo/semantics/openAccess