During postmoem no tattoo is visible, but according to deceased family, there was a tattoo present. What evidence can indicate the same?

Tattoo marksDesigns made in the skin by multiple small puncture wounds with needles or electric vibrator dipped in coloring matter. The most permanent pictures are made when the dye penetrates the dermis.If the dye is deposited into deeper layers of the dermis, it will be removed by phagocytes.Most of the marks are found on the arms, forearms, and chestIf the pigment has been deposited below the epidermis, it will very slowly become fainter and ceain pigments, such as vermilion, and ultramarine may disappear after 10 years.The rate of fading depends not only on the composition of the pigment but also on the depth to which it penetrates the skin and the site which is tattooedFaded tattoo mark becomes visible by the use of UV lamp (or) rubbing the pa and examining with magnifying lens (or) Infrared photography (or) Lymph nodes near a tattoo mark show deposits of pigment Dyes commonly used are:Indian ink.Carbon (black).Cinnabar or vermilion (mercuric sulphide) red.Chromic acid (green),Indigo,Cobalt.Prussian blue (ferric ferrocyanide).Ultramarine (blue).(Refer: Rajesh Bardale - Principle of Forensic Medicine & Toxicology, 1st edition, pg no: 70, 71)