Introduction
The auricle is a visible part of the ear. A preauricular (front part of the ear) cyst is a very uncommon congenital deformity seen in front of the ears on facial skin. It is also variably known as preauricular sinus, preauricular fistula, and preauricular pit. Preauricular cyst occurs during the embryonic development of first and second branchial clefts, which form the ear. It mainly involves the helix of the right ear and is usually detected by regular ear, nose, and throat examinations. It is mostly unilateral but can be bilateral also.
What Is the Incidence of a Preauricular Cyst?
-
Preauricular cysts are very rare, with an incidence of 0.1 to 0.9 % in the general population.
-
It mainly affects females more than males.
What Are the Causes of a Preauricular Cyst?
The auricle (the visible part of the ear) usually develops during the sixth week of gestation of the embryonic life. Auricle develops by fusion of six mesenchymal tissues known as “Hillocks of his.” The cause behind the formation of the preauricular cyst are:
-
Incomplete fusion of auditory hillocks (hillocks of his).
-
Presence of deformity in auditory hillocks.
-
Genetic causes due to the involvement of chromosome 8q11.
-
Congenital face and head anomalies (birth defects).
What Are the Signs and Symptoms of a Preauricular Cyst?
A preauricular cyst is mostly asymptomatic but can present symptoms if it gets infected like:
-
A hole/pit is present in front of the ear.
-
Swelling in front of the ear.
-
Presence of pus discharge if it gets infected.
-
Pain/tenderness in the front of the ear on palpation.
-
Redness in the area is seen.
How Can We Diagnose a Preauricular Cyst?
It is usually seen during the routine ear, nose, and throat examination. Various diagnostic methods are:
-
Clinical Examination and History: A complete clinical examination of the area is done to check for signs of infections or any opening /fissures present in front of the ears. It is also important to rule out any congenital head and face anomalies (birth defects).
-
Magnetic Resonance Imaging (MRI): Magnetic resonance imaging scans are done to locate the exact size and position of the cyst. It also helps to differentiate whether it is a cyst or has formed an abscess.
-
Renal Ultrasound: Ultrasound of the kidney is done to rule out the presence of branchial cleft cyst and kidney syndrome-like Branchio-Oto-Renal (BOR) syndrome (it mainly affects children).
-
Audiometry Test: It is done by checking the external ear for the presence of any deformities like preauricular pits or tags. An audiometry screening test is recommended after birth to check for any sensorineural or conductive hearing loss in infants born with preauricular pits or tags.
-
Fine Needle Aspiration Cytology (FNAC): It is done by using a small gauge needle to withdraw/aspirate the fluid contents in case of an abscess and is sent to the lab for culture sensitivity testing. It is done in patients who are not responding to antibiotic therapy. It also helps to identify the causative organism (mostly Staphylococcus aureus).
What Is the Treatment of a Preauricular Cyst?
Treatment modalities for a preauricular cyst are:
-
Antibiotics: A full course of antibiotics is given to the patient for the cystic infections to reduce or subside.
-
Incision and Drainage: It is done to drain the pus and reduce the swelling, especially in the patient with which abscess is not responding to antibiotics. The drained fluid is sent for the pus culture.
-
Drainage by Lacrimal Probe: Some authors recommend doing incision and drainage by using a blunt edge of the lacrimal probe (a thin instrument) and placing it into the sinus to facilitate effective drainage. This technique prevents the need for an incision (surgical skin cut).
-
Inside-Out Technique: It is one of the most recent surgical techniques that is performed to reduce the recurrence of a preauricular cyst. In this technique, local/general anesthesia is given near the front of the ear, and an elliptical cut is given around the opening. After the flap is raised, a magnifying glass or microscope is used to identify each branch of the cystic tract/fistula until every dead end is removed completely.
-
Fistulography With Surgical Dissection: Fistulography can be done before or during the surgery to identify the cystic tract in a patient with a fistula.
After the surgery, the patient is prescribed prophylactic antibiotics like Penicillin and is recalled after seven to eight days for stitch removal and follow-up.
Can a Preauricular Cyst Reoccur After the Surgery?
Incomplete removal of the cystic tract or fistula can lead to the recurrence of the cyst, so it is advised to completely remove the cyst along the fistula.
Conclusion
Although the incidence of preauricular cyst is very low, it can occur spontaneously due to birth defects or the presence of any head and face anomalies. Various surgical techniques are available to remove the preauricular cyst, but complete removal of the cyst is very important to avoid recurrence. Auditory screening and physical examination of an infant after birth are mandatory to determine the presence of any inborn head or face anomalies and hearing loss. If any organ deformity or hearing loss is detected, the infant/child should be referred to an otolaryngologist for further diagnosis and management.
