Pilonidal Cyst (Sinus Pilonidalis) - Information on Minimally Invasive Surgery and Treatment of Pilonidal Cysts

Obese, heavily hairy men have a significantly increased risk of developing a pilonidal cyst (sinus pilonidalis). Inflammation in deeper layers of the skin is often the starting point for this condition. Heavy sweating also contributes to the development of inflammation. 

A pilonidal sinus—also colloquially referred to as a pilonidal cyst—often forms where “broken” hairs grow deeper into the subcutaneous tissue. Friction from the buttocks and increased sweat production irritate the skin, which can lead to inflammation. Deep within the tissue, a foreign body granuloma forms, intended to enclose and isolate the ingrown hair. This granuloma can eventually become infected and further inflamed, resulting in an abscess. As a result of this inflammation, fistula tracts form, which can spread further into the subcutaneous fatty tissue or even reach the skin’s surface, where they form a visible fistula opening. 

The following factors contribute to the development of a coccygeal fistula:

• heavy body hair,
• excessive sweating,
• sedentary occupations,
• severe obesity, and
• acne inversa.

A coccygeal fistula manifests as a reddened and swollen lump on the buttocks @ Pepermpron /AdobeStock

Men between the ages of 20 and 30 are particularly likely to suffer from a coccygeal fistula. Men are generally affected about twice as often as women. The incidence rate cited in the literature is 20–30 cases per 100,000 inhabitants.

Essentially, three forms of pilonidal sinus (sinus pilonidalis) are distinguished:

1. asymptomatic,
2. acute-abscessing,
3. chronic-inflammatory.

An asymptomatic pilonidal cyst—as the name suggests—does not cause symptoms and therefore generally does not require immediate treatment. However, it is not uncommon to see fistula openings on the skin’s surface, which can become inflamed over time.

The acute abscess-forming form is characterized by swelling, redness, and pain. Fever may also occur. The chronic-inflammatory coccygeal fistula, on the other hand, is characterized by fluctuating symptoms. A key feature of the chronic form of the coccygeal fistula is the recurrent discharge of pus from the fistula openings.

Furthermore, the chronic-inflammatory form will not heal spontaneously and therefore requires treatment. If the inflammatory changes in the area of the coccygeal fistula persist over a longer period of time, there is also a risk of squamous cell carcinoma, a malignant skin tumor.

Squamous cell carcinoma is the second most common malignant skin tumor @ Luis /AdobeStock

To diagnose a pilonidal sinus, specialists do not need extensive equipment, as the diagnosis is made visually. A medical history, visual examination, and, if necessary, palpation of the affected skin areas are often sufficient to reliably diagnose a pilonidal cyst. If the skin around the fistula is gently pressed, purulent discharge can usually be squeezed out, which further supports the diagnosis.

In terms of differential diagnosis, specialists in coccygeal fistulas must always rule out a presacral teratoma, as well as spina bifida (“open back”) in newborns, especially in atypical cases. In addition, Crohn’s disease or psoriasis should always be considered.

A coccygeal fistula is usually treated surgically. In the acute phase, a puncture incision may also be made to relieve the abscess and allow the discharge to drain. Once the inflammation has subsided somewhat, specialists in coccygeal fistulas will surgically close the fistula openings. Whether the fistula is primarily sutured or debrided and then allowed to heal naturally must be decided on a case-by-case basis.

The patient’s preference is particularly important here, as immediate suturing generally resolves the coccygeal fistula more quickly, but recurrences—that is, the reappearance of the fistula—are more common. Natural wound healing, on the other hand, takes significantly longer but has a lower recurrence rate.

Since the inflammatory forms of a coccygeal fistula develop from an asymptomatic form, the asymptomatic coccygeal fistula is of particular importance in prevention. Anal fistulas can usually be prevented through good anal hygiene, shaving, and follow-up examinations in cases of recurrent inflammation in the anal area.

Specialists in coccygeal fistulas are typically physicians specializing in proctology, coloproctology, and general surgery. In some cases, however, specialists in dermatology, visceral surgery, or gastroenterology may also be involved.

Above, we’ve also compiled a list of specialists in coccygeal fistula surgery and specialized centers near you.

What is a coccyx fistula?

A coccygeal fistula is an inflammatory condition of the subcutaneous fatty tissue in the gluteal cleft, usually caused by ingrown hairs.

Is a pilonidal cyst dangerous?

Generally not, but if it becomes chronic, it can lead to recurring symptoms and infections.

Does a pilonidal cyst require surgery?

In most cases, yes, since spontaneous healing is rare and surgical procedures yield the best results.

How long does it take to heal after surgery?

Depending on the procedure, several weeks; with minimally invasive procedures, the recovery time is significantly shorter.