Moles, freckles and liver spots are sometimes difficult to distinguish from each other and are often incorrectly referred to as birthmarks.
What are the differences?
The 3 are better distinguished under the microscope (biopsy). With a freckle, the amount of pigment cells (melanocytes) are equal, only more pigment is produced.
A liver spot, also known as a sun spot, actually has nothing to do with your liver. In the medical world, a liver spot is also called lentigo. Lentigines (plural) contain both more pigment cells and more pigment. The pigment cells are evenly distributed in the lower layer of the epidermis.
In moles, there are also more pigment cells, but unevenly distributed and accumulated in the skin.
Freckles, known in the medical world as ephelides, are benign spots. They are mainly located on the face and sunlit areas such as the upper body, forearms and lower legs. They are formed under the influence of sunlight. That is why they become darker in color during the summer period and just lighter in the winter months. Most people recognize freckles very easily. They are more common in people with lighter hair color and skin type (red and blond hair).
Lentigines are brown spots and also arise under the influence of sunlight. These stains will not go away on their own. They can arise from puberty, then they are called lentigines simplex. Lentigines solaris or lentigo senilis (liver spot or age spot) are also benign variants that develop at a later age. You often see them on the backs of the hands and on the cheeks.
Birthmarks can be present from birth and increase over the years. They can be of different colors: black, brown, red or even skin-colored. The shape also varies from smooth, raised to spherical. A light brown birthmark is difficult to distinguish from a freckle or lentigo. Birthmarks can suddenly increase from puberty, and existing birthmarks can also grow and increase in number during pregnancy.
While you’re here
Melanocytes also called pigment-producing cells. These cells are located in the lower layer of your epidermis, hairs and also in the iris of your eyes. Per square millimeter, between 1000 and 2000 melanocytes are found in the skin. That is about 5% to 10% of the cells in the basal layer of the epidermis. Although their size varies, melanocytes are typically 7 ɥm long and, like squid tentacles, interact with keratinocytes (skin cells). A melanocyte is roughly ‘connected’ to 40 keratinocytes. More about pigment cells