Characterization of Mast Cells Residing in Cutaneous Neurofibromas

Mast cell Neurofibroma Histamine release Ryoichi Kamide, MD, Department of Dermatology, The Jikei University School of Medicine, Nishishinbashi 3-19-18, Minatoku, Tokyo 105 (Japan) showed a comparable histamine release to those from normal skin in response to nonimmunologic stimuli. The maximum net histamine release from neurofibroma-derived mast cells stimulated by A23187 and compound 48/80 was 23.4 ± 11.0 and 12.0 ± 1.8%, respectively, while that of normal skin was 38.5 and 11.5 ± 3.0%, respectively. Comments This study confirms that cutaneous neurofíbromas in patients with neurofibromatosis contain a large number of mast cells. Cutaneous mast cell suspension, which efficiently responds to nonimmunologic secretory stimuli, was obtained by enzymatic dispersion of neurofíbromas. These mast cells may provide a new approach to the elucidation of the etiological roles of mast cells in the development of neurofíbromas in neurofibromatosis [4] and an experimental source of human connective tissue mast cells for the investigation of mast cell-mediated cutaneous inflammation. References Benyon RC et al: Human mast cells: Their dispersion, purification, and secretory characterization. J Immunol 1987;138:861–867. Lawrence ID et al: Purification and characterization of human skin mast cells: Evidence for human mast cell heterogeneity. J Immunol 1987:139:3062–3069. Tharp MD et al: Functional heterogeneity of human mast cells from different anatomic sites: In vitro responses to morphine sulfate. J Allergy Clin Immunol 1987;79:646–653. Riccardi VM: Mast-cell stabilization to decrease neurofibroma growth. Arch Dermatol 1987;123:1011–1016. Introduction s rHeterogeneity of mast cells derived from different rspecies and anatomic sites has been demonstrated in ¢recent years [1–3]. Increased numbers of cutaneous mast Acells have been observed not only in mastocytosis but also tin several cutaneous neoplasms, including neurofíbromas, and in various inflammatory conditions. In this study, weexamined the mast cell population density and histaminecontent in cutaneous neurofíbromas. In addition, the invitro