Proliferating trichilemmal cyst (PTC) is a benign lesion arising from dermal or epidermal structures containing cells capable of proliferating. These cysts are often localized in the hairy area, predominantly on the head, neck, and upper trunk. Their wall may consist of granulation tissue and mature fibrous tissue, while the content is often sebaceous or keratinous material. Proliferating trichilemmal cysts should be differentiated from other types of cysts, such as epidermoid cysts, because they may have different prognoses and treatment strategies.
History of the disease and interesting historical facts
Proliferating trichilemmal cyst was first described in the medical literature in the mid-20th century. However, cysts resembling PTCs have been encountered before and can be found in works from different periods of medical history. In 1969, several authors classified these lesions as cysts arising from dermal atypical cell growth. In the 20th century, researchers such as Driscoll and Lee expanded on their observations of trichilemmal cysts, leading to an understanding of their biology and pathogenesis, as well as the development of more effective diagnostic and therapeutic approaches.
Epidemiology
Proliferating trichilemmal cysts are quite rare lesions and their exact prevalence is unknown, however, some studies report that they account for less than 1% of all dermatological tumors. According to the available literature, PTCs are most often found in patients aged 20 to 50 years, with women suffering from this disease twice as often as men. Possible reasons for this gender imbalance may be related to hormonal features and differences in skin structure. In most cases, cysts are observed as single lesions, however, in rare cases, multiple cysts may be present, which requires a more thorough examination.
Genetic predisposition to this disease
To date, clearly established genetic factors predisposing to the development of proliferating trichilemmal cysts have not yet been identified. However, according to some studies, certain mutations in genes responsible for cell cycle regulation and programmed cell death may be associated with the occurrence of these formations. The most studied are the TP53 and PTEN genes, which play an important role in the control of cell proliferation. Dysfunction of these genes can lead to uncontrolled cell growth, which leads to the formation of a cyst.
Risk factors for the development of this disease
Risk factors that contribute to the development of proliferating trichilemmal cysts include:
- Genetic predisposition
- Hormonal changes, including pregnancy and menopause
- Exposure to ultraviolet radiation
- Physical trauma to the skin
- Presence of chronic inflammatory skin diseases
- Some chemicals, especially specific substances used in cosmetics and manufacturing.
These factors can both provoke the growth of cysts and affect their pathogenesis.
Diagnosis of this disease
Diagnosis of a proliferating trichilemmal cyst begins with a clinical examination. The main symptoms include:
- The appearance of a painless formation on the skin
- The presence of a movable node under the skin
- Acceptable general condition of the patient
Laboratory tests are usually nonspecific, but sometimes tests are performed to look for infection or inflammation. Radiological examinations are limited to ultrasound, which can help differentiate from other types of cysts. Differential diagnosis includes true epidermoid cysts, sebaceous glands, and pyogenic granulomas.
Treatment
Treatment of proliferating trichilemmal cysts should be based on clinical indications. General tactics include:
- Monitoring of asymptomatic lesions
- Surgical removal in the presence of cosmetic or functional complaints
- Pharmacological treatment in case of concomitant inflammatory processes
Surgical treatment should be performed by an experienced surgeon to minimize recurrence and damage to surrounding tissues. Pharmacological treatment may include antibiotics in case of inflammation or associated infections.
List of medications used to treat this disease
Currently, there are no specific drugs for the treatment of proliferating trichilemmal cysts. However, in cases of inflammation, the following may be used:
- Antibiotics (eg, amoxicillin)
- Nonsteroidal anti-inflammatory drugs (eg, Ibuprofen)
- Corticosteroids (if needed, to reduce inflammation)
These drugs do not improve the outcome of the disease itself, but help with associated inflammatory processes.
Disease monitoring
Patient monitoring includes regular follow-up examinations after surgical removal of the cyst or a clear case of observation. The prognosis for patients with proliferating trichilemmal cysts is generally good, and recurrence is relatively rare. However, attention should be paid to changes in the size or character of the lesion, as complications such as inflammation and infection may occur.
Age-related features of the disease
Proliferating trichilemmal cysts can occur in people of different age groups, but are more common in young and middle-aged people. In children and adolescents, this disease is less common, while in older people, the picture may be different - the formation of cysts is associated with the degradation of the skin and its structures. In older people, cysts can appear as a concomitant phenomenon in the presence of other dermatological diseases.
Questions and Answers
- What are the main symptoms of proliferating trichilemmal cyst? The main symptoms are a painless formation under the skin, mobility of the structure and the absence of general somatic manifestations.
- Should a proliferating trichilemmal cyst be removed? Cyst removal is required in case of cosmetic or functional complaints, as well as complications.
- What is the chance of recurrence after cyst removal? The recurrence rate after proper surgical removal is less than 5%.
- Can proliferating trichilemmal cyst be treated with medication? There is no specific drug treatment, but antibiotics and anti-inflammatory drugs may be used in case of inflammatory processes.
- What is the role of genetic predisposition in the development of proliferating trichilemmal cysts? Genetic predisposition may play a role, but specific mutations associated with PTC have not yet been identified.
