[Lithiasis of the tonsil. Questions, answers].

Imaging, clinical and frequency of the tonsil's calculi in function of the size of the calculi: inframillimetric calculi much frequent, not visible by imaging; small calculi from 1 to 7 mm frequent, visible by the imaging and much often asymptomatic; big ones superior of 7 mm rare, becoming exceptional and much often symptomatic above 15 mm.

MRI pattern of progressive multifocal leukoencephalopathy (PML) in AIDS. Pathological correlations.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease which occurs in immunodepressed subjects and is particularly frequent in AIDS. Some authors having drawn attention to the protean aspect of the disease and claimed that AIDS may lose its basic characteristics and affect the grey matter as well as the white matter, we reviewed a series of 8 patients who had been biopsied and/or autopsied and had been examined at least once by MRI. In this series, contrary to what is regularly observed in toxoplasmic abscesses we did not find any lesion of the grey matter or any mass effect.