What do large moles on the body indicate?

People usually dislike people with big birthmarks (I mostly mean sexual attractiveness, but not only). It seems that the presence of moles correlate with something bad in the organism. With what?

Is that possibly that the moles can correlate with bad features of character? I have found the photo of Kim Il Sung:

Spathi said:

Is that possibly that the moles can correlate with bad features of character?

Very unlikely. A nevus (the term for moles, birthmarks, etc) is the result of irregular development of certain skin cells during one's life, and there is little connection between common skin conditions such as these and a person's character. Virtually everyone has some number of moles, birthmarks, skin tags, or other nevi.

Spathi said:

It seems that the presence of moles correlate with something bad in the organism.

Not necessarily. I suspect a leading cause of the development of nevi is DNA damage leading to abnormal cell division, proliferation, or aggregation and at least one article seems to support this:

Although the genetics of melanoma has been widely studied, much less is known about genes involved in the development of benign moles. Variations in several genes, including FGFR3, PIK3CA, HRAS, and BRAF, are involved with benign moles. The most-studied of these is the BRAF gene. A variant in BRAF leads to the production of an altered protein that causes melanocytes to aggregate into moles. This altered protein also triggers the production of a tumor-suppressor protein called p15 that stops moles from growing too big. In rare cases, BRAF gene variants together with loss (deletion) of the CDKN2A gene causes a lack of p15, which creates the potential for mole cells to grow uncontrollably and become cancerous (malignant). The formation of cancer is increasingly likely when combined with environmental factors, such as cell damage caused by ultraviolet radiation exposure.

Source: https://medlineplus.gov/genetics/understanding/traits/moles/

Such DNA damage or alteration is most likely caused by random chance (always a possibility), chemical or radiation damage, or viral infection. While there may be some congenital/inherited conditions that make development of nevi more likely, these would only affect a very small percentage of people.

I know that some evolutionary biologist have suggested that as skin lesions are one of the few obvious indicators of disease, we may have become predisposed to avoiding contact with people displaying them. Until fairly recently, some of the most infectious diseases became visible through a range of different skin lesions. These days it has become far less reliable as an indicator of risk, but it does seem people can get uncomfortable making contact, even though most visible lesions we see are harmless to others. This discomfort can be magnified if the lesions appear inflamed, bleed or exclude other fluids, these lesions are usually covered.
Really, as we age certain types of lesions, like skin tags, become more common, but people can be quite familiar with some of these, but there is a large cosmetic industry engaged in removing many of these things.

In early Summer of this year, when I switched to short sleeved shirts from long sleeves, there was a mole on my arm that had Red lines emanating from it.

I figured "That's not right," and made an appointment with my dermatologist.

Of course by the time of the appointment the Red lines had disappeared. The dermatologist looked at it and said "It's just a mole. Don't worry about it."

I mentioned the Red lines, which triggered "We'll do a biopsy just in case."

Result: "Pre-cancerous, but we got it all."

Lesson: If it's unusual, get thee to an expert!

Cheers,
Tom

With regards to moles becoming cancerous, the recommendation is that if the appearance of a mole begins to change get it checked out. Changes include size, shape, color, border, and texture. So know your moles.
It is not widely known that melanomas can occur in places other than the skin including the eye, under nails, in the nose, and in the urogenital area. Usually, there are symptoms such as bleeding, visual disturbance, or pain that are unusual and send you to the doctor (or should) to get it checked out. Incidence increases with age for all types of melanomas.

@Spathi, the picture of Kim Il Sung that you posted doesn't seem to me to display a mole. Instead, the growth on his neck might be a fatty deposit -- also known as a sebaceous cyst.

I have a mole of a diameter approximately 1.5 cm on my back. Should I ask a doctor whether this is can be something bad?

Spathi said:

I have a mole of a diameter approximately 1.5 cm on my back. Should I ask a doctor whether this is can be something bad?

Yes. The default answer to "should I go see a doctor for...?" is always yes.

Spathi said:

I have a mole of a diameter approximately 1.5 cm on my back. Should I ask a doctor whether this is can be something bad?

Most moles are 6 or so mm in diameter. My brother has a birthmark about 2 cm in width. It is flat not raised, dark brown, and irregular in shape. AFAIK it has never changed. The question should be has yours changed any recently? Even if it has not changed, depending on your age particularly if you are younger it may be worth getting an appraisal of the possibility that it could be pre-cancerous and should be closely monitored.

Spathi said:

TL;DR Summary: People usually dislike people with big birthmarks; it seems that the presence of moles correlate with something bad in the organism. With what?

Is that possibly that the moles can correlate with bad features of character?

The way that society treats non-standard appearance means that it it hardly surprising if someone with a 'strange' feature gets reactions from the rest of society in ways that could trigger neuroses and hence odd behaviour. This could be resented by the very folks who reacted in an uncharitable way to the original feature. 'You don't look like me so you're bad' is universal in the animal kingdom and is an example of basic Darwinism.

Read 'The Elephant Man' and other stories.