Histiocytosis X and Pericarditis - A Rare Association and a Difficult Diagnosis.

Histiocytic disorders are a group of rare diseases with systemic involvement and with multiple clinical manifestations. We present the case of a 51 years old patient investigated for dyspnea with orthopnea, dry cough, asthenia, muscular weakness and ataxia. The association of previous symptoms with skin lesions, diabetes insipidus, partial hypophyseal insufficiency and pericarditis induced many diagnostic debates. The diagnosis is Histiocytosis X must be sustained by tissue biopsy with immunohistochemical assay or genetic testing. The particularity of our patient is the presence of pericarditis, rarely associated with histiocytosis. Collaboration between medical specialties is mandatory in order to treat this disorder.