It is difficult to say based on the limited informations about the sample, but I could assume that this is a Masson's Trichrome staining. Briefly: blue/green - collagen, red/pink - cytoplasm, dark pink/brown - nucleus.
Presence of the adipose tissue (white area on the right) and a lot of collagen (green) suggest that the sample highly likely comes from dermis. The large structure pointed by the arrow looks like an eccrine sweat gland. Here, you can see it in classical haematoxylin and eosin staining:
Alternatively, see: http://medcell.med.yale.edu/histology/skin_lab/eccrine_sweat_glands.php