What Is Blue Nevus?

Blue nevus is also called benign mesenchymal melanoma, blue nevus, melanoma, melanoma fibroma, benign mesenchymal melanoma, etc. It is a benign tumor composed of blue nevus cells. There are three types of blue mole: ordinary blue mole, cellular blue mole, and combined blue mole. Common blue moles have large skin lesions, often progress, and occasionally benign metastases to the lymph nodes. It can be born or appear after birth. In addition to the skin, it can also occur in the oral mucosa, cervix, vagina, spermatic cord, prostate and lymph nodes. Blue moles may be malignant.

Basic Information

nickname: Benign mesenchymal melanoma, blue nevus, melanoma, melanoma fibroma, benign mesenchymal melanoma, etc.
English name: blue nevus

Visiting department: dermatology
Multiple groups: female
Common causes: Abnormal melanocyte aggregation in the dermis
Common symptoms: Blue, gray-blue, blue-black pimples, nodules, or patches

Causes of blue mole

Blue moles are caused by abnormal melanocyte aggregation in the dermis and are relatively rare. Mostly accompanied by pigmented nevus, cardiac myxoma, cutaneous mucosal myxoma, and related to nodular mast cell proliferation. Its histology is related to pigment cells and mast cells.

The blue-gray appearance of blue moles is mainly the visual effect of dermal melanin covering the epidermis. Long waves of visible light pass through the deep dermis and are absorbed by pigment cells, while short waves (blue) have weak penetrating power and are scattered by the skin and returned to the skin surface. , And then reflected to the eyes of the viewer was blue, the occurrence of explosive blue mole is related to sun exposure.

Blue mole clinical manifestations

It is more common in women and often occurs from childhood. It occurs on the skin of the face and limbs, especially on the back of the hands and feet, as well as on the waist and hips. It is occasionally found in the conjunctiva, oral mucosa, prostate and cervix. The damage is usually single or multiple, with blue, gray-blue, blue-black pimples, nodules, or patches. The diameter is several millimeters to several centimeters. Blue moles include common blue moles, cellular blue moles, and combined blue moles and malignant blue moles.

Common blue mole

Small, generally 3-10 mm in diameter, blue, gray-blue or blue-black pimples or nodules, rounded top, smooth surface. Its melanocytes are distributed in the lower 1/3 of the dermis. Occurs on the arms and back of the feet, but also on the face, sides of the extremities, and waist and hips. This type of blue nevus does not undergo malignant transformation and does not retreat for life.

2. Cellular mole

It is a large blue or blue-black, with a fairly solid nodule. The diameter is usually 1-3 cm or larger. The surface is smooth or leafy, and skin lesions are common in the crotch region and hip region, and malignant changes can occur.

3. Joint blue mole

Blue nevus can be combined with nevus nevus, and histopathology can distinguish two nevus cells.

4. Malignant blue mole

Malignant melanoma that develops on the basis of cellular blue nevus is called malignant blue nevus.

Blue mole check

Histopathological examination is helpful for the diagnosis and classification of diseases.

Blue mole diagnosis

According to clinical characteristics, the diagnosis of blue nevus is not difficult, but the diagnosis requires pathological examination.

Blue mole differential diagnosis

Skin fibroma

No melanocytes, dopa positive.

2. Blue mole malignancy

In addition to atypical melanocytes, necrotic lesions are common, and residual melanocytes are seen.

3.Mongolian spot

It is present at birth and can subside or fade in color within a few years.

4. Ota mole

Lesions are generally limited to the first and second branches of the unilateral trigeminal nerve. The center of the patch is dark and the edges are gradually faded.

5. Ito mole

It occurs in one side of the shoulder and neck, the supraclavicular region, and the upper arm. It is a pigment lesion of the posterior supraclavicular nerve and the lateral arm cutaneous nerve.

Blue mole complications

Nodular mast cell hyperplasia, skin mucosal myxoma.

Blue Mole Treatment

Generally blue moles are less than 1 cm in diameter and are stable for many years without change, usually without treatment.

Those with a diameter greater than 1 cm who have recently appeared blue nodules or enlarged blue nodules should be surgically removed. Histopathological examination of the nodular blue nevi that has spread suddenly should be performed. The depth of the resection should include subcutaneous fat to ensure complete removal of abnormal melanocytes. If pathological examination proves that there is malignant change, it should be treated according to the principle of treatment of malignant melanoma. If there are suspicious changes in plaque blue nevus, regular inspection and resection should be considered. Cell nevus may be malignant and should be removed. Excision of skin lesions should reach subcutaneous fat to ensure complete removal, because the cell blue mole often reaches the subcutaneous tissue.