Dermoid cyst
Introduction
Introduction to dermoid cyst A dermoid cyst is a congenital disorder and is a type of hamartoma. It is a congenital cyst formed by the primordial surface of the skin cells that is off-site. It is often located under the skin, occasionally under the mucosa or in the body. The skin-like cyst is deep in the area, does not adhere to the skin of the surface layer, is soft and tough, has a large tension, and its base often adheres to deep tissues such as fascia or periosteum and cannot move, and may be affected by long-term compression. , an impression is formed on the local bone surface. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: skin cysts
Cause
Cause of dermoid cyst
Congenital factors (95%)
The dermoid cyst is a congenital skin-like neoplasm. Due to abnormal development of the embryonic stage, part of the ectodermal rupture is buried under the skin or conjunctival tissue. It is easy to occur in the inner or outer part of the eyelid, and the site of occurrence is related to the sacral suture, which often originates from this kind of suture. It can also occur in eyebrows, tendons, and conjunctiva. The shape is round or oval, and the size is not the same. Generally, the walnut is large and soft, and when the tension of the capsule is large, the hardness is increased like a tumor. There is a connective tissue envelope around the cyst, the surface is smooth, the boundary is clear, slightly elastic, generally does not adhere to the skin, but often adheres to the periosteum, because it is congenital, it is easy to find early.
Pathogenesis
It is derived from epithelial cells that are left in tissues during embryonic development.
Pathophysiology
Dermoid cysts and epidermoid cysts are derived from epithelial cells that are left in the tissue during embryonic development.
Prevention
Dermoid cyst prevention
This disease is a congenital disease, just need to prevent the residue that occurs during the surgical resection and avoid recurrence. Epidermal cysts are a type of disease caused by retention of neurogenesis and are benign tumors. Because the capsule is full of keratin, it is also known as keratinocyte cyst. Personal hygiene should be done after surgery, change clothes frequently, cut your nails, and keep your skin clean. You can't use your fingers to squeeze the wound to avoid infection. It is necessary to take anti-inflammatory drugs, anti-bacterial infection drugs, etc. after surgery. In addition, we must keep the patient's mood comfortable.
Complication
Dermoid cyst complications Complications skin cysts
When the cyst is large, it may cause difficulty in breathing and is life-threatening.
Symptom
Symptoms of Dermoid Cysts Common Symptoms Cystic cystic masses of persistent pain. There are skin sinus sinus in the lower back.
1. The course of the disease is long, and the time from symptom onset to visit is between 1 year and several years. The average time from symptom onset to diagnosis is about 8 years.
2. Multiple skin-like cysts have been reported, and it is common to have both intracranial and intraspinal canal. And there is a familial disease.
3. With a deformed dermoid cyst can be combined with other congenital malformations, such as cervical occipital region skull deformity, skull fracture, spina bifida, visceral transposition.
4. Symptoms and signs Most patients with intracranial pressure increased as a common symptom, located in the posterior cranial fossa may have ataxia, walking instability, nystagmus and other symptoms of cerebellar damage. In the saddle area, visual acuity and visual field disorder may occur, and other symptoms include epilepsy and hemiplegia. Dermoid cysts are often associated with skin sputum, which is an important clinical feature of dermoid cysts. The fistula of the skin can be open, or latched, or have only one fiber band. The skin is mostly located in the midline and occasionally in the lateral position. Cranial endothelium cysts are most common in the occipital skin, followed by the top and frontal nose.
The skin-like cyst is deep in the area, does not adhere to the skin of the surface layer, is soft and tough, has a large tension, and its base often adheres to deep tissues such as fascia or periosteum and cannot move, and may be affected by long-term compression. , an impression is formed on the local bone surface. The lipoma is flat and lobulated, located under the skin, and the local skin is pushed along the sides of the tumor with fingers, and an orange peel-like sign may appear.
According to the age of onset and clinical features, especially those with skin sputum, diagnosis can be made, and those without dermabrasis can be diagnosed by radiology, but the preoperative diagnosis is difficult.
Examine
Examination of dermoid cysts
1. Skull plain film: Circular skull defect or localized bone erosion can be seen in the flat slice of the skull, which is of great value for qualitative diagnosis of tumor.
2. Cerebral angiography: can show the performance of space-occupying lesions such as normal vascular displacement.
3. CT: The dermoid cyst is a low-density area due to the large amount of fat. The CT value reaches -100Hu, sometimes it can be calcified, and it has a high and low mixed density shadow. Generally, the boundary is clear, and occasionally there is a high density, and the CT value is above 20Hu. Intensive scanning is generally not enhanced. The density of the tumor is uneven, and there may be a fat density zone, and the adjacent bone wall may be concave or defective. The expansion of the cavity is rare.
4. MRI: The dermoid cyst was short T1 and showed high signal on both T1 and T2-weighted images.
5.B super performance: the echoes in the circle are circular or elliptical, and the boundary is clear. The strong echo light group is visible, and the sound is strong and compressible.
Diagnosis
Diagnosis and differentiation of dermoid cyst
diagnosis
1 history: more common in children and adolescents, cystic masses, slow growth and large, generally no symptoms;
2 clinical examination: cystic mass, dermoid cysts occur in the mouth area, no adhesion to the surrounding, palpation can be dough-like flexibility;
3 puncture examination: the skin-like cyst can extract milky white bean-like secretions.
Differential diagnosis
1 sublingual cyst 2 rupture cyst 3 thyroglossal cyst.
