[Histiocytic proliferative diseases. Discussion of a case report]

The case of a ten month old female with initial clinical and histological findings suggestive of inappropriate macrophage activation syndrome is reported. Subsequently, clinical and pathological changes refuted this diagnosis and demonstrated that the patient had Langherans cell histiocytosis. Clinical, laboratory and pathological findings characteristic of each type of histiocytosis are reviewed. Histological and immunohistochemical studies allow to establish the diagnosis of Langherans cell histiocytosis. The finding of erythrophagocytosis in our patient suggests that two types of histiocyte proliferation can coexist in the same individual.