Plasmacytoid Dendritic Cell Dermatosis Associated to Myeloproliferative/Myelodysplastic Neoplasms

• Published in: The American journal of surgical pathology Vol. 46; no. 12; pp. 1623 - 1632
• Main Authors: Machan, Salma, Alonso-Dominguez, Juan M., Sánchez García, F. Javier, Nieves Salgado, Rocío, Soto, Carlos, Castro, Yolanda, Pajares, Raquel, Manso, Rebeca, Santonja, Carlos, Serrano del Castillo, Cristina, Piris, Miguel A., Requena, Luis, Rodríguez Pinilla, Socorro M.
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins 01-12-2022
• Subjects: Dendritic Cells - pathology; Humans; Interleukin-3 Receptor alpha Subunit; Leukemia, Myelomonocytic, Chronic - pathology; Myelodysplastic Syndromes - complications; Myelodysplastic Syndromes - pathology; Myeloproliferative Disorders - complications; Myeloproliferative Disorders - diagnosis; Myeloproliferative Disorders - genetics; Skin Diseases - pathology; Skin Neoplasms - genetics; Skin Neoplasms - pathology
• ISSN: 0147-5185; 1532-0979
• DOI: 10.1097/PAS.0000000000001960

Cutaneous lesions in the setting of myeloproliferative neoplasms and myelodysplastic syndromes are poorly understood. We report 6 patients with pruritic papular eruptions composed of mature T-lymphocytes with large clusters of CD123-positive cells. Double immunohistochemical studies demonstrated a lack of myeloid cell nuclear differentiation antigen in the CD123-positive cells, which expressed SPIB, confirming that they were mature plasmacytoid dendritic cells. Four patients were diagnosed with chronic myelomonocytic leukemia and 2 with myelodysplastic syndromes (AREB-I and myelodysplastic syndromes with 5q deletion, respectively). All patients had a long history of hematological alterations, mainly thrombocytopenia, preceding the cutaneous disorder. Nevertheless, the skin lesions developed in all cases coincidentally with either progression or full-establishment of their hematological disease. Most cutaneous lesions disappeared spontaneously or after corticosteroid treatment. Molecular studies performed in both bone marrow and cutaneous lesions in 2 patients demonstrated the same mutational profile, confirming the specific, neoplastic nature of these mature plasmacytoid dendritic cells-composed cutaneous lesions.