Search

Resume Introduction La mastocytose systemique est caracterisee par une proliferation anormale de mastocytes dans differents organes. Nous rapportons le cas original d’une mastocytose systemique revelee par un œdeme vulvaire. Observation Une femme de 24 ans consultait en dermatologie pour un œdeme vulvaire apparaissant au moment des rapports sexuels. Elle presentait des episodes vasomoteurs des membres inferieurs, une urticaire du tronc a l’effort, des diarrhees et des douleurs osseuses. Le bilan biologique montrait une tryptasemie a 29,7 μg/L et une histaminemie a deux fois la normale. Le myelogramme mettait en evidence une infiltration par des mastocytes dysmorphiques. La recherche de la mutation D816V du gene c-kit etait positive. Les biopsies duodenales revelaient des amas de mastocytes avec plus de 15 mastocytes agreges. L’immunomarquage CD2 etait non contributif et le CD25 non realise. Une osteopenie trabeculaire etait constatee. Nous avons pose le diagnostic de mastocytose systemique indolente (ISM variant Ia) d’apres les criteres OMS 2008. Un traitement symptomatique a ete instaure (anti-histaminiques anti-H1 et anti-H2, antileucotrienes), ainsi qu’un suivi clinicobiologique. Discussion Les symptomes qui ont conduit ici au diagnostic de mastocytose systemique avec atteinte de plusieurs organes etaient des signes cutanes qui pouvaient paraitre mineurs, lies a la degranulation mastocytaire. Il s’agit du troisieme cas decrit de mastocytose revelee par un œdeme vulvaire et du premier cas revelant une atteinte systemique. Les deux cas precedemment decrits avaient revele une mastocytose cutanee pure. La mastocytose, systemique ou cutanee, doit faire partie des diagnostics differentiels a evoquer devant un œdeme vulvaire.

Systemic mastocytosis is characterised by abnormal proliferation of mast cells in various organs. We report an original case of systemic mastocytosis revealed by vulvar oedema.A 24-year-old patient was examined in the dermatology department for vulvar oedema appearing during sexual intercourse. She presented vasomotor dysfunction of the lower limbs, urticaria on the trunk on exertion, diarrhoea and bone pains. Laboratory tests showed serum tryptase of 29.7μg and plasma histamine at twice the normal value. Myelogram results showed infiltration by dysmorphic mast cells. Screening for c-kit D816V mutation was positive. Duodenal biopsies revealed mast-cell clusters with aggregation involving over 15 mast cells. CD2 staining was inconclusive and CD25 staining could not be done. Trabecular osteopenia was found, and we thus made a diagnosis of indolent systemic mastocytosis (ISM variant Ia) as per the WHO 2008 criteria. Symptomatic treatment was initiated (antiH1, H2, antileukotrienes) and clinical and laboratory follow-up was instituted.The cutaneous signs leading to diagnosis in this patient of systemic mastocytosis involving several organs were seemingly minimal signs associated with mastocyte degranulation. This is the third recorded case of mastocytosis revealed by vulvar oedema and the first case revealing systemic involvement. The two previously reported cases of vulvar oedema revealed cutaneous mastocytosis alone. Mastocytosis, whether systemic or cutaneous, must be included among the differential diagnoses considered in the presence of vulvar oedema.