There is a black line on the thumb nail

Over the years, the number of cancer patients has increased. Cancer is a terminal illness that cannot be completely cured even with our current science and technology. These cancer patients warn us that we should not only develop good living habits, but also go to the hospital for regular check-ups. Only by understanding our physical condition well can we prevent it in advance, detect and treat the disease in time, and recover soon.

The nail matrix nevus is a type of nevus. The most common symptom of nail matrix nevus is the black line on the nail, which can easily turn into melanoma and is easily ignored. Moles are abnormal tissues that appear during human development. The phenomenon of moles is very common in life, and almost every mole has the potential to become cancerous.

With the popularization of medical knowledge, people have a more comprehensive understanding of moles and are more vigilant about the cancerous transformation of moles. However, moles in certain special parts of the body are often easily overlooked, the most typical of which is the nail matrix nevus.

Causes

There are many reasons for the formation of black lines on the nails/nevus. Systemic pigmentary diseases and combined nail pigmentation can be seen in acanthosis nigricans, Addison's disease, Peutz-Jeghers syndrome and vitamin B12 deficiency, Cushing's syndrome after adrenalectomy, or Laugier-Hunziker syndrome. Local inducing factors include trauma, fungal infection, eczematous changes, and subungual hemorrhage. Other factors can be seen in drugs (chemotherapeutic drugs, antimalarial drugs, minocycline or gold preparations) that induce the increase of melanocyte activity, which can lead to the black line of the nail. Clinically, it should be diagnosed as black line of the nail.

Manifestation

① Epithelioid nevus cells are arranged regularly, the epidermis is mildly acanthotic and hyperkeratotic, and the epidermal ridges can be elongated.

② If the nevus cells are close to the dermis or inside the dermis, the nevus cells are spindle-shaped. The cellular nevi in ​​the epidermis contain a large amount of pigment, and the lower the location, the less pigment there is in the cells.

③ Generally, unless there is trauma or malignancy, there is little or no inflammation in the dermis. In addition, according to the location of nevus cells in the skin, they can be divided into junctional nevus, mixed nevus and intradermal nevus. Malignant melanoma is suspected in the following cases:

① Cells show anaplasia or atypia: mainly enlarged and darkly stained nuclei, and cells of varying sizes;

② Malignant junctional differentiation: The nevus cells at the junction of the epidermis and dermis show atypical proliferation, the cells are scattered and not in nests, or the nests are fused, and there is a continuous proliferation of atypical melanocytes in the basal layer between the epidermal ridges;

③ Atypical moles break through the basal layer and penetrate into the dermis;

④Except for juvenile melanoma, generally, the nuclear mitosis of nevus cells cannot be seen in the deep dermis. If this phenomenon occurs, it is often a sign of malignant transformation;

⑤ Tumor cells spread throughout the entire layer of the epidermis.