Related articles: Melanoma
Definition
Cutaneous melanoma is a malignant tumor that originates from melanocytes (skin cells that produce melanin), which begin to proliferate without control.
Melanomas can develop on an intact, healthy and asymptomatic skin, or from a neo (or nevus) that has existed since birth (congenital) or appeared during the course of life (acquired). Sometimes, these cancers can also arise on the conjunctiva and on the oral or genital mucosa.
In the genesis of melanoma, excessive exposure to ultraviolet radiation takes on a central role, mainly represented by the rays of the sun but in some cases even by tanning lamps. If intense and intermittent, in fact, this exposure can damage the DNA of skin cells and trigger the tumor transformation. Severe sunburn in childhood and adolescence greatly increases the risk of melanoma.
Subjects with phototype 1-2 (light skin, with freckles, hair and light eyes) have a greater predisposition to develop a melanoma, compared to people of dark / olive complexion and with eyes, dark / black hair (phototype 4).
Familiarity (the risk increases if there has been at least one other case of melanoma in one or more 1st degree relatives), genetics and immunosuppression states can also promote tumor onset.
Even patients with a positive personal history for a previous melanoma are at an increased risk of developing other skin cancers.
Other factors to watch out for are the presence of a large congenital mole and the increase in the number of acquired melanocytic nevi. Atypical (dysplastic) nevi can be considered precursors of a melanoma.
Most common symptoms and signs *
- Changes in the appearance of a mole
- Erythema
- Swollen lymph nodes
- macules
- Atypical snows
- Multiple pulmonary nodules
- Nodule
- Solitary pulmonary nodule
- papules
- plaques
- itch
- Nephrotic syndrome
- Skin Ulcers
- Pericardial effusion
Further indications
The main symptom of cutaneous melanoma is the obvious changes in the appearance of a mole. In particular, a suspicious lesion has alterations of shape (which is irregular, not symmetrical, with jagged edges, not well delineated, penetrated or with incisure) and of color (which is not homogeneous, with red-brown, white, black spots or blue inside the mole itself, or that turns to a dark color). Another alarm bell is the change in dimensions (over 6 mm and with a tendency to progressive enlargement, both in width and thickness, in a rather short time), especially if associated with any signs of inflammation in the surrounding skin, with itching, spontaneous bleeding, ulceration, tenderness and appearance of a nodule or reddened area.
Melanomas differ in terms of size, shape and color (usually, they are pigmented), and tendency to give metastasis. Therefore, we can distinguish 4 main types: superficial diffusion melanoma, lentigo maligna melanoma, acral lentiginous melanoma and nodular melanoma.
Superficial spreading melanoma is the least aggressive and most common form (it represents about 70% of all cutaneous melanomas). It occurs most commonly on the legs in women and on the trunk in men.
Lentigo maligna type melanoma is more frequent in the elderly, has a slow growth rate and rarely spreads to other parts of the body. It appears on the face or on other photo-exposed areas, usually as a spot on the skin of irregular shape, asymptomatic, flat, brown or brown.
Acral lentiginous melanoma, on the other hand, is rarer. It appears under the nails, on the palm of the hand or on the sole of the foot. Initially, it is similar to a hematoma and can go unnoticed until it has spread to the body.
Finally, nodular melanoma is the most aggressive form: it extends rapidly, invades the tissue deeply from its earliest stages and spreads rapidly to other parts of the body. Represents 10-15% of all melanomas. It often appears on the head, neck, back or chest in the form of a dark-colored papule, or as a plaque of variable color from pearl white to gray-black.
The development of metastases depends on the depth of the dermal invasion.
Local metastases lead to the formation of papules or satellite nodules, which may be more or less pigmented. Skin metastases or other organs are also possible via the lymphatic and hematic pathways (especially in the liver, lungs, bones and brain). In case of spread, the prognosis is poor.
Early diagnosis (up to 1 mm of penetration depth) is of great importance in melanoma therapy, since if treated promptly, it is almost always treatable.
Examination of suspected pigmented lesions occurs after a biopsy. The treatment of choice consists in surgical resection, possibly with the removal of the nearest lymph nodes (sentinel lymph nodes) to assess the possible presence of micrometastases.
In the case of metastatic disease, chemotherapy is required; however healing is very difficult.
The self-examination of the skin performed by the patient himself can favor the identification of some suspicious features of the moles, facilitating early diagnosis.
