[Usefulness of bone scintigraphy for staging in a case of histiocytosis of the temporal bone].

We present the case of a 43-year-old man diagnosed of insipid diabetes and hypogonadotropic hypogonadism in whom a right temporal bone lesion was observed in the control MRI, thus leading to his admission. A bone scintigraphy with 99mTc-HMDP showed increased uptake in the right temporal region with sphenoidal extension, coinciding with the MRI. In addition, increased uptake having less intensity and size was observed in the left temporal region. A biopsy on the newly appearing mouth ulcers in the jugal mucous was performed and showed Langerhan's cells, the diagnosis of histiocytosis X being confirmed. Six months later a new MRI indicated disease progression with bilateral temporal involvement. The bone scan findings in this case provided a more exact extension diagnosis of the disease than the MRI.