What does keratoma (seborrheic keratosis) look like
The appearance of a keratoma largely depends on the age of its existence.
In the initial stage, this formation protrudes very slightly above the skin level, differs slightly from it in density and has a color very close to the body. The shape of the foci is round or oval.
Then, as the number of epidermal cells in the formation increases, the keratoma increases in thickness and in height. These formations are visible to the naked eye – mili-like cysts and comedon-like spots.
One of the most common symptoms for keratoma, visible to the naked eye, is a surface that somewhat resembles the earth, cracked after rain. Such a pattern is formed by layers consisting of keratinized cells of the epidermis.
You can talk about this syndrome when a person suddenly has a lot of keratomas, especially on the trunk. In 35% of cases, this condition is associated with black acanthosis. About 50% of patients report severe itching in the keratoma area. 
In addition to the clinical form – on a broad basis – there is a form of seborrheic keratosis on the leg. The human papillomavirus has a very distant relation to this form of keratoma. Only in isolated cases, during histological examination of such formations, there were indications of signs of a viral lesion.
The Leser-Trel syndrome may indicate the presence of malignant tumors of internal organs, according to some reports - late stages. Most often we are talking about adenocarcinomas of the stomach, colon, breast cancer, lymphoma or leukemia. The average life expectancy of patients with this syndrome is 11 months. 
This means that if multiple keratomas appeared gradually and have been present on the trunk for many years – most likely, this syndrome is not in question.
Some researchers question the existence of the syndrome. This is due to the fact that these malignant tumors are more common in older patients, as well as seborrheic keratosis itself.