Silvery hair with dyschromatosis: Griscelli syndrome type 3 or familial gigantic melanocytosis.

We herein illustrate a case of an adult male presenting with silvery hair and generalized guttate hypopigmented macules on a background of diffuse cutaneous hyperpigmentation, since birth. Histopathology showed enlarged melanocytes with abundant melanin. Based on these clinicopathological features, differential diagnoses considered were Griscelli syndrome 3 (GS3) and familial giagantic melanocytosis. GS3 belongs to a group of inherited autosomal recessive (AR) disorders of partial albinism, known as silvery hair syndromes, while familial gigantic melanocytosis (FGM) is a putative disorder of dyschromia with silvery hairs. A pertinent literature search revealed hyperpigmentation or dyschromatosis as a rare manifestation of silvery hair syndromes, especially in dark-skin populations. A comparative analysis of previously reported cases depicted close morphological similarities between GS3 and FGM. We discuss the uncertainty pertaining to cases described in literature as FGM, to be truly representative of a distinctive entity, or merely a morphological variation of GS3.