Solitary eosinophilic granuloma of the calvaria

Aims and background: Histiocytosis X is a condition characterized by an abn ormal proliferation of histiocytes with a variable granulomatous and inflam matory component; bone involvement is almost always present. The aim of thi s study was to define the management of solitary eosinophilic granuloma (EG ) of the calvaria in adult patients, in relation to the size and site of th e lesion. Methods: Fourteen patients, ranging in age from 7 to 45 years, with solitar y eosinophilic granuloma of the calvaria were surgically treated by craniec tomy or curettage and cranioplasty. We subgrouped the lesions into two type s: A) lesions localized inside the diploe and/or compressing the cerebral p arenchyma below but without dural infiltration; B) lesions with mainly intr acranial growth, compressing the cerebral parenchyma and infiltrating the d ura. The infiltrated dura mater in type B lesions was replaced with a dural patch. Cranioplasty was performed in lesions with a diameter of 4 cm or mo re and/or located in aesthetically exposed areas of the skull. Results: None of the patients died during the study and no local or systemi c recurrences were observed during follow-up (min. 3 yrs, max. 8 yrs). Conclusions: surgical treatment of patients with isolated EG of the calvari a not only is simple and quick but also allows histological diagnosis of th e osteolytic lesion. These patients do not require further adjuvant treatme nt. Cranioplasty should be performed when the lesion has a diameter of 4 cm or more, when it is located in aesthetically exposed areas of the skull su ch as the frontal or temporal bones, or when it produces alterations of the normal skull morphology.