Fig. 2From: NRASQ61K mutated primary leptomeningeal melanoma in a child: case presentation and discussion on clinical and diagnostic implicationsCyto-morphological examination of CSF. May-Grünwald-Giemsa staining shows numerous polymorphic cells with large cytoplasm and prominent nucleoli (a). On immunohistochemical profile cells are positive for S100 (b)Back to article page