Two unusual cases of argyria: the application of an improved tissue processing method for X-ray microanalysis of selenium and sulphur in silver-laden granules

Using a simplified tissue processing method for X-ray microanalysis, we have characterized the elemental composition of silver-laden granules deposited in the skin of two patients with argyria. The introduction of ethanol as a fixative and nylon mesh as a supporting grid, and the avoidance of electron staining, have facilitated the minimization of unwanted microanalytical emission peaks generated from conventional chemicals and metals, which often disturb precise clarification of elements of pathological interest in argyria. The two main X-ray microanalytical findings in this study were: (i) the consistent presence of sulphur and the inconsistent occurrence of selenium in the silver-laden granules, and (ii) successful mapping of the distribution of trace amounts of selenium present in argyria. The simplified tissue processing method could be useful in future critical X-ray microanalysis studies.