Nevus, nevus pigmentosa, also known as nevus pigmentosa or spotted nevus, is most common benign skin tumor composed of normal cells of a pigmented nevus, sometimes on surface of mucous membranes. There are many clinical manifestations. The color is mostly dark brown or jet black, and colorless moles without coloring are also found.
Some say that a "black mole" is melanoma. This is true?
Nevus is most common benign skin tumor. A mole consists of normal pigmented nevus cells. The color is mostly dark brown or jet black. There are also colorless nevi. Although moles are benign tumors, when stimulated by certain conditions, moles can also become malignant and become so-called "melanomas" such as prolonged rubbing, pressure and other irritants, or exposure to sunlight, physical and chemical irritants, etc.At same time here also to promote relevant medical knowledge of "melanoma"! !
Melanoma is a malignant tumor of melanocytes. Melanocytes are found mainly in skin, but can also be found elsewhere, especially in eyes. The vast majority of melanomas occur on skin.Causes of melanoma
Solar radiation, consisting of UV-B (280-320 nm) and UV-A (320-400 nm), is main causative factor and the risk is associated with:
Other risk factors include "teratoid mole syndrome", which is a family disorder in which atypical moles carry a low to moderate risk of melanoma.
Pathological types of melanoma
Diagnosing melanoma requires expert knowledge, as it can look just like a harmless mole in its early stages. Signs and symptoms of melanoma include:
Classification of malignant melanoma by TNM:
T primary tumor; TX primary tumor cannot be assessed; T0 no evidence of primary tumor; Ts malignant melanoma in situ.
T1 tumor thickness ≤ 1.0 mm with or without ulcer; T1a tumor thickness ≤ 1.0 mm, grade II or III without ulcer; T1b tumor thickness ≤ 1.0 mm, grade IV or V ulcer.
Tumor thickness T2 1.012.0 mm with or without ulcer; tumor thickness T2a 1.012.0 mm without ulcer; tumor thickness T2b 1.012.0 mm with ulcer.
Tumor thickness T3 2.014.0 mm with or without ulcer; tumor thickness T3a 2.014.0 mm without ulcer; tumor thickness T3b 2.014.0 mm with ulcer.
Tumor thickness T4 4.0 mm with or without ulcer; tumor thickness T4a 4.0 mm without ulcer; tumor thickness T4b 4.0 mm with ulcer.
N lymph nodes; NX cannot assess condition of lymph nodes; N0 no metastases to regional lymph nodes.
N1 has metastases to one lymph node; N1a clinically recessive metastases; N1b clinically dominant metastases; N223 Regional lymph node metastasis or intralymphatic metastasis, although no regional lymph node metastasis.
N2a clinical occult metastases; N2b clinical dominant metastases; N22 no local lymph node metastases, but satellite lesions or metastases between primary tumor and lymph nodes; N3: Metastases or fusions in 4 or more lymph nodes Metastases to lymph nodes or regional lymph nodes Metastases with satellite lesions or metastases between tumor and lymph nodes.Melanoma treatment
Surgical excision - usually treats thin formations. Immunotherapy and, to a lesser extent, chemotherapy may have some experimental effect on advanced tumors.Melanoma prognosis
Prognostic features are tumor thickness (Breslow depth), depth relative to skin structure (Clark), type of melanoma, presence of ulceration, presence of satellite lesions, and presence of regional or distant metastases.
Regarding tumor thickness at diagnosis: thin melanomas (<0.75 mm) have a good prognosis and are usually cured by surgical resection alone, tumors greater than 4 mm thick at diagnosis often metastasize and can have extremely aggressive sexual growth.