A Case of Systemic Mastocytosis: An Ultrastructural and Immunohistochemical Study of Dermal Mast Cells in Relation to Activation of the Epidermal Melanin Unit

The document details a case study of a 1-month-old boy with systemic mastocytosis, presenting with symptoms like skin lesions and systemic issues, including fever and hepatosplenomegaly. Despite hematologic abnormalities and a high mast cell count in bone marrow, a year of prednisone treatment improved organ size and reduced bone marrow mast cell percentage but did not alleviate skin symptoms. Histological and immunohistochemical analysis of skin and lymph node biopsies revealed dense infiltrates of atypical mast cells and increased melanogenesis. The study concludes that while prednisone can decrease organ mast cell infiltration, it does not change the atypical mast cells' morphology, highlighting the necessity for ongoing monitoring of mastocytosis patients.