title: [Metameric macular and papular skin mastocytosis].
abstract: BACKGROUND
  Mastocytosis is characterised by the presence of abnormal quantities of mastocytes in one or more organs. Although it occurs in systemic forms of mastocytosis, isolated skin involvement is the predominant presentation, particularly in children, in the form of more or less extensive though non-systematic lesions. Herein, we report a case of maculopapular cutaneous mastocytosis that is unusual in terms of its metameric topography.
  
  
  METHODS
  A 16-year-old youth presented with an erythematous maculopapular rash of 18 months' duration and involving pruritic inflammatory episodes strictly localised in segment T8 to the left. The skin biopsy showed a significant increase in the number of dermal mastocytes (CD117+). No KIT mutations were found in the skin lesions nor in the unimpaired skin of the opposite side. Further investigations ruled out systemic mastocytis.
  
  
  CONCLUSIONS
  Herein, we report a case of cutaneous mastocytosis that is unusual in terms of its metameric disposition. There have been only two previous reports of segmental cutaneous mastocytis. The two pathological hypotheses involved precessional dermatitis that renders the skin surface susceptible to homing, and somatic mosaicism (type 1) with local mastocyte proliferation.
authors: Service de dermatologie, CHU d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France.
authors: M
authors: M
authors: Maciejewski
authors: Cabinet de dermatologie, 11, rue Georges-Clemenceau, 49300 Cholet, France.
authors: J-M
authors: JM
authors: Debarre
authors: Service de médecine interne, hôpital Tenon, 4, rue de la Chine, 75020 Paris, France.
authors: S
authors: S
authors: Georgin-Lavialle
authors: Cabinet de cytologie et d'anatomie pathologiques, BP 40428, 49004 Angers cedex 01, France.
authors: S
authors: S
authors: Kettani
authors: Département de génétique médicale, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France.
authors: S
authors: S
authors: Olschwang
authors: Service de dermatologie, CHU d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France.
authors: M
authors: M
authors: Guérin-Moreau
authors: Service de dermatologie, CHU d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France.
authors: Y
authors: Y
authors: Le Corre
authors: Service de dermatologie, CHU d'Angers, 4, rue Larrey, 49933 Angers cedex 9, France. Electronic address: LuMartin@chu-angers.fr.
authors: L
authors: L
authors: Martin
mesh_terms: D000293:Adolescent; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000473:pathology*; D034701:Mastocytosis, Cutaneous / Q000473:pathology*; D012867:Skin / Q000473:pathology
keywords: Homing; KIT; Mastocyte; Mastocytose; Mastocytosis; Metamerism; Métamère