Cysts

Epidermal Cyst

An epidermal cyst is a cystic tumour located in the dermis and filled with keratin debris. It is also called an epidermoid cyst or epithelial cyst. It grows slowly and is seen in various parts of the body (the back, neck, face, scrotum, earlobe, genitals, scalp and abdomen). It is a benign (non-cancerous) growth. Although its content is keratin, it may also contain hair follicles and fat particles.

It accounts for 15–20% of all types of cyst and is the most common skin lesion. It is seen at any age, but is more common between the ages of 20 and 40. Its size ranges from 1 cm to 5 cm. In men it is commonly seen in the scrotal area; in women it is often seen beside the breast, on the neck and on the back. Among malignant and benign epidermal cysts, the rate of malignant epidermal cysts is 3–4%, which shows that epidermoid cancer has a certain place among cancer types.

Inside the keratin-filled cyst there may be hair, cartilage, dental tissue and nail. Epidermal cysts can form through implantation of tissue (epidermal or subcutaneous) as a result of trauma or surgery. However, they can also form spontaneously.

What are the symptoms of an epidermal cyst?

Swelling under the skin
Redness
Tenderness
Pain
Discharge from the cyst

Which departments treat epidermal cysts?

General surgery
Dermatology
Plastic, reconstructive and aesthetic surgery

How are epidermal cysts diagnosed?

Ultrasonography (USG)
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Radiological imaging
Excisional biopsy
Incisional biopsy
Fine-needle aspiration cytology (FNAC)

How are epidermal cysts treated?

Surgical treatment: surgical methods are generally used for treatment, and this procedure has a high success rate. The epidermoid layer, i.e. the area containing the cyst, is removed completely. The cyst may be fluid or solid. A fluid-filled epidermal cyst can be drained, but it may recur after this procedure. A solid cyst is removed surgically through an incision.

Although the way the procedure is carried out varies according to the site, it is usually performed as an outpatient procedure. It is an inexpensive procedure taking about 15 minutes. Some epidermal cysts become inflamed; antibiotic treatment is given for these.

Milium

Milia are superficial keratin cysts, usually smaller than 3 mm. When there is only one, the term milium is used. They can develop spontaneously, in which case they are called primary milia, or due to another cause, in which case they are called secondary milia. Primary milia are keratin cysts arising from vellus hair (fine "peach fuzz" hair) and sebaceous glands, while secondary milia arise from sweat glands.

Trichilemmal Cyst

Trichilemmal cyst, these cysts are also known as sebaceous adenoma; as epidermal or epidermoid cysts because they arise from the epidermis; and as pilar cysts because they arise from the hair root. Nevertheless, they are counted as neither pilar cysts nor epidermoid cysts. When examined under the microscope, trichilemmal cysts are found among epidermoid or pilar cysts. In practice, however, these three terms are used interchangeably for cysts.

These cysts are often seen as slow-growing intradermal or subcutaneous tumours on the face, neck, back and scrotum. Although they were previously referred to as sebaceous cysts, they contain keratinous material rather than sebaceous material. The cysts occur in multiples and usually show autosomal dominant inheritance. Trichilemmal cysts are quite rare and are known as steatocystomas.

Why do trichilemmal cysts (sebaceous adenoma) form?

These cysts form because of blockage of the gland, infection and inflammation of the hair follicle, and excess testosterone levels. Genetic factors and certain hereditary diseases can also cause them; for example, basal cell naevus syndrome and Gardner's syndrome are among the causes of trichilemmal cyst formation.

Which areas do trichilemmal cysts affect?

These cysts are mostly seen on the scalp, ears, nape of the neck, face and arms. In practice, however, they can be seen anywhere on the body except the palms and soles. In men they are seen particularly on the chest and testicles (scrotum). They are more common in areas of the body with dense hair.

Physical characteristics of trichilemmal cysts

Although the cysts vary in size, they appear as well-defined, roundish, soft lesions. Inflamed lesions are firm and quite painful. The cysts are structurally mobile in the area where they are located. The contents of the cysts include:

Fibrous tissue and fluid
An oily substance with the consistency of strained cheese, i.e. keratin. For this reason the cysts are also called keratin cysts. Its characteristic feature is the cheesy texture or food-like smell of the material.
There may be purulent and bloody content. This material is slightly sticky, fluid and serosanguineous.

Treatment of trichilemmal cysts

The only treatment for these cysts is surgery. The cysts are surgically removed under local anaesthesia (surgical excision). Lesions successfully excised during the operation have no likelihood of recurring.

Proliferating Trichilemmal Tumour

Proliferating Trichilemmal Cyst

Proliferating trichilemmal cyst (PTC), also known as pilar tumour of the scalp, is a rare, slow-growing benign skin neoplasm that develops from the outer root sheath of the hair follicle. It was first reported in 1966 by Wilson Jones as a proliferating epidermoid cyst. Later, however, various names were used for this neoplasm in the literature, such as hydatidiform keratinous cyst, invasive pilomatrixoma, proliferating trichilemmal tumour and giant hair matrix tumour. Although it is usually seen on the scalp, it has also been reported on the neck, face, ears, lips, oral cavity, fingers, hands, buttocks, thighs, vulva, lower and upper limbs and mons pubis. 80% of patients are women, most of them elderly.

Steatocystoma Multiplex

Steatocystoma multiplex (SM) is a skin disease presenting with widespread, numerous cystic lesions. It is seen most often in adolescence and early adulthood, when sebaceous activity peaks, on the areas of the body where pilosebaceous activity develops: the trunk, neck, arms, armpits, groin and scalp. In steatocystoma multiplex, facial involvement may accompany body involvement, but predominant or exclusive facial involvement is rarely seen.

Vellus Hair Cyst

Eruptive Vellus Hair Cyst

The first case of eruptive vellus hair cyst (EVHC) in the literature was reported by Hoffmann in 1903 under the name "epidermal cysts containing vellus hairs". In 1977 Esterly and colleagues used the term EVHC for the first time. Since 1977 many cases of EVHC have been reported. In our country, the first case, reported by Aras and colleagues in 1994, was followed by case reports by Erkek and Bozdoğan in 1999 and by Aksungur and colleagues in 2003.

EVHC is described as a disease showing both autosomal dominant inheritance and sporadic cases. It occurs equally often in women and men, usually between the ages of 2 and 24. It is characterised by asymptomatic, soft, skin-coloured or yellow papules 1–4 mm in diameter, numbering from 20 to 200.

Faulty development of the vellus hair follicle is implicated in the pathogenesis of EVHC, and this faulty development is thought to create an occlusion at the level of the infundibulum, causing hair retention and cystic dilatation of the follicle.

Thyroglossal Duct Cyst

What is a thyroglossal duct cyst?

A thyroglossal duct cyst is a remnant of tissue along the path by which thyroid cells migrate from the floor of the mouth to the neck during embryonic life, which becomes a cyst seen in the midline of the neck after birth. Normally this path closes early in pregnancy, but if the cells along it do not disappear, these remnants form a thyroglossal cyst. Thyroglossal cysts can develop anywhere along this path, but they are usually located in the upper middle part of the neck, at or below the level of the hyoid bone. The cells inside the thyroglossal duct secrete mucus, which gradually accumulates and makes the cyst grow.

Thyroglossal cysts are the most common congenital cysts of the neck. Half are diagnosed in childhood, and more than two-thirds are diagnosed before the age of 30. It is noticed as a round, smooth, firm mass in the midline of the neck. The mass moves with swallowing and movement of the tongue. It usually causes no signs other than a small swelling, but if it becomes infected there may be redness and pain over the mass, enlargement of the mass and spontaneous discharge from it. Very rarely it can cause difficulty in swallowing and breathing.

The diagnosis can usually be made from the history and physical examination. It may sometimes appear after an upper respiratory tract infection. The full blood count and thyroid function tests should be reviewed. Ultrasound also helps in the diagnosis: whether the thyroid is in its normal position and the features of the cyst are determined by ultrasonography.

How is it treated?
If the thyroglossal duct cyst is infected, antibiotic treatment is started; surgery can be carried out after the infection has been treated.

At surgery, the cyst and its extension up to the base of the tongue are removed. During the operation, the middle part of the hyoid bone is also removed together with the cyst and duct. This is the most important step taken to prevent the cyst from recurring. The removed tissue is sent for pathological examination.

What will happen in hospital?

Your child will come to hospital on the day of surgery and be taken to the operating theatre. After the surgical procedure, which is carried out under general anaesthetic, your child will stay in the recovery room until fully awake. Once the pain has been controlled with painkillers, feeding will be started and your child will be sent home the same day.

Your child can have a bath 1 week after the operation. Until then there will be a small dressing on the neck, and sport and active physical exercise should be avoided. Your child will come for a check-up 2–3 days after the operation and the dressing will be changed.

If swelling, redness or discharge appears in the same area after the operation, you should consult your doctor again.

Mucocele

Mucoceles are common soft tissue lesions of the oral cavity. The word means a cavity filled with mucus (muco = mucus and coele = cavity). Mucus is the secretory product of the major and minor salivary glands. The formation of a mucus-filled cavity is pathological and occurs in two situations: extravasation and retention. The most common aetiological factor in mucoceles is extravasation, which occurs when mucus located in the ducts or acini spreads into the surrounding tissues; this is called a "mucus extravasation cyst". It is often caused by local trauma and irritation. Chronic biting, after anaesthesia or as a bad habit, and blows are the most commonly encountered forms of trauma, while hot and toxic substances are the main causes of local irritation. Because these cysts have no epithelial lining, they are not classed as true cysts. Rarely, mucoceles can form when saliva accumulates in a dilated duct; mucoceles formed in this way are called "retention cysts". These are true cysts, and the cyst epithelium may be mucoid, squamous or oncocytic. Clinically, they are asymptomatic lesions ranging in size from a few mm to a few cm, bluish-transparent (superficial) or of normal mucosal colour (deep), most often located on the lower lip lateral to the midline, and rarely on the underside of the tongue or the buccal or palatal mucosa.

Eccrine Hidrocystoma

Hidrocystoma is a rare benign cystic lesion of the skin arising from the sweat glands. It can originate from eccrine or apocrine glands. Hidrocystoma is seen most often in the head and neck area. Solitary lesions occur equally often in both sexes, while multiple lesions are more common in women.

Eccrine hidrocystomas are small (1–6 mm in diameter), thin-walled cysts that may be single or multiple. In the head and neck area they are most often located in the periorbital and malar (cheek) region. Apocrine hidrocystomas, on the other hand, are usually solitary and 3–15 mm in size.

Apocrine Hidrocystoma

Apocrine hidrocystoma (AH) is a benign cystic tumour. AH lesions are solid-cystic lesions most often arising from adenomatous cystic proliferation of the apocrine glands. They tend to be located particularly in the head and neck area. Hidrocystomas rarely exceed 10 mm and are usually 1–3 mm in size. Giant and multilocular hidrocystomas are rarely seen. Left untreated, hidrocystomas grow over time. Their pathophysiology is unknown. The cysts are benign, rarely cause symptoms and rarely recur when removed. Clinically, the lesions are bluish, translucent, solitary nodular lesions and are usually located on the face. Pigmented naevus, melanoma, blue naevus and cystic basal cell carcinoma should be considered in the differential diagnosis of AH.