Problems in differential diagnosis of non Langerhans cell histiocytosis with pituitary involvement: case report and review of literature.

Differentiation among various non Langerhans cell histiocytoses granulomatous in adults is often difficult. Patients, moreover, may not have endocrinologic abnormalities. A 53-yr-old patient was admitted owing to central diabetes insipidus and partial hypopituitarism. Magnetic resonance imaging revealed a space-occupying lesion near the hypophyseal stalk, along with diffuse signal uptake in the cerebellar region. Laboratory chemistry showed monoclonal gammopathy of IgGkappa, and hormone tests disclosed insufficiency in the gonadotropic and somatotropic axes. The clinical picture was marked by multiple cutaneous xanthogranulomas, ataxic gait with blurred speech, compatible with pseudobulbar pontocerebellar symptomatology. Stereotactic pituitary biopsy was histologically classified as nonspecific granulomatous disease. Supplemental biopsies taken from the cutaneous periorbital xanthogranulomas were histologically and immunohistochemically consistent with non Langerhans cell histiocytosis. Systemic cortisone treatment as well as local radiotherapy to the pituitary lesion with a total of 18.0 gy had no impact on the progression of disease-growing tumor and progressing neurologic symptoms. Systemic granulomatoses cannot always be classified according to specific defined diseases. Differential diagnosis in the current patient should include the possibility of Erdheim-Chester disease, necrobiotic xanthogranuloma, and adult disseminated xanthoma.