Mucus Retention Cyst

A mucus retention cyst forms when one of the mucus glands just below the vocal cord’s free margin becomes plugged. Mucus glands in this location secrete mucus in order to bathe and lubricate the vocal cords, but if a gland becomes obstructed, then the mucus it produces gets trapped and accumulates, leading to a mucus retention cyst. They typically occur without any correlation to vocal overuse, in contrast to epidermoid cysts as well as nodules and polyps.

Symptoms

A mucus retention cyst can cause hoarseness, because it interferes with the normal vibrations of the vocal cords and the accuracy of their match with each other (see the videos below). The cyst is most often unilateral—that is, occurring on one cord but not the other. It appears as a bulge or deformation of the vocal cord’s free margin, and sometimes undersurface, and it may be yellowish in color.

Treatment

The cyst may be surgically removed, by creating a small incision on the vocal cord and then dissecting the cyst from the cord. Photos of the surgical process can be found below. Also, the two videos below show how removing this kind of cyst can improve the voice.

Is it a Cyst or Polyp?

Sometimes a vocal cord lesion resembles a polyp but is not; it is in fact a cyst. Not an epidermoid or saccular type, but a mucus retention cyst. A small mucus gland becomes plugged, and its secretions cannot escape. The result is a cyst filled with mucus.

For proper differentiation from a polyp, it is important to know that mucus glands are not found within the primary vibratory mucosa covering the cord. Instead, they populate the area from just under the vocal cord margin, downward into the subglottis and below. Cysts form typically just below the margin, likely due to the gland being affected by adjacent vibration. And by seeing that the swelling is centered just below rather than at the margin, one can distinguish between polyp and mucus retention cyst.

vocal lesion below the margin on the left vocal cord — Lesion below the margin (1 of 5)

This older man has developed a rough voice quality. He is not a “vocal overdoer.” Yet, in this distant view, it might appear initially that he has a left vocal cord polyp. What tells us it isn’t? Not only his quiet nature and life that is inconsistent with vibratory trauma. But that the lesion is emerging from just below the margin rather than it being at the margin, as vibratory injuries are…

Vibratory flexibility (2 of 5)

The open phase of vibration at high pitch under strobe light (which shows vibratory flexibility and match).

Vocal cord margin above cyst (3 of 5)

At the closed phase of vibration, much of the cyst is hidden below the left cord, and one can see the actual margin of the cord (faint dashed line), is above the cyst.

Margin of cords (4 of 5)

At low pitch, open phase of vibration, note the actual margin of the cords (faint dashed lines, again), where a polyp would normally occur.

Cyst occur below match (5 of 5)

The closed phase of vibration closes completely, with the cyst below the match of the two vocal cord margins. Conclusion? This is a mucus retention cyst, not a polyp!

Surgical Removal of a Mucus Retention Cyst

A mucus retention cyst occurs when a small mucus gland becomes plugged and its secretions accumulate, progressively swelling into a cyst. It isn’t known why this happens. There does not seem to be a correlation with vocal overuse, in contrast to vocal nodules, polyps and even epidermoid cysts. Instead, inflammation (viral, or acid reflux-related, for example) seems to be the culprit that plugs the duct of the mucus gland.

In this long series, an older male public speaker presents with severe hoarseness of many months’ duration. Elseehere, the swelling of his right cord was described as a polyp, rather than a mucus retention cyst. The only solution is surgery(microlaryngoscopy); voice therapy is ineffective for this lesion.

Working with long instruments down a laryngoscope, a very superficial incision is made, the “dragonfly wing” mucosa overlying the cyst is peeled back to expose the cyst. The wall of the cyst itself is also “dragonfly wing” in thickness, making the cyst subject to rupture during removal. Usually if rupture occurs, it is nearing the completion of removal, when most of the dissection has been accomplished and making it possible to remove the entire cyst. In this case, the cyst is delivered intact. Vocal recovery is virtually to normal.

Right vocal cord cyst (1 of 20)

In open (breathing) position, the right vocal cord cyst is seen (left of photo). Consistent with the absence of vocal overuse or abuse, the left vocal cord shows no evidence of phonotrauma (vibratory injury).

vocal cord cyst under strobe illumination — Cyst under strobe illumination (2 of 20)

Under strobe illumination, closed phase of vibration, the cyst indents the good (left) cord (right of photo).

vocal cord cyst margin projection under strobe light — Cyst margin projection (3 of 20)

Also under strobe light, open phase of vibration shows more clearly the margin projection of the cyst.

Operating view of cyst (4 of 20)

In the operating room, the view inverts the image so that now the right vocal cord cyst is on the right.

Injecting Lidocaine in a vocal cord with cyst — Injecting Lidocaine (5 of 20)

The first step is to inject the mucosa with lidocaine with epinephrine, using a tiny needle and avoiding injecting the cyst itself. The purpose is “hydrodissection” (expanding the planes of tissue that will subsequently be dissected) and for hemostasis.

Fully infiltrated right cord with lidocaine — Preparing for Microlaryngoscopy (6 of 20)

Fully infiltrated right cord. When the incision is made, much of this infiltration will leak out.

microlaryngoscopy showing Incision of mucosa on right vocal cord — Incision of mucosa (7 of 20)

To lift the delicate “kitchen plastic wrap” mucosa from the cyst, just one blade of a microscissor is being used only as an elevator.

Incision in process for microlaryngoscopy — Incision in process (8 of 20)

The cyst wall is coming into view.

dissection of cyst in microlaryngoscopy — Dissection of cyst (9 of 20)

Dissection around the cyst is largely accomplished using a blunt dissector, scissors, and an occasional fiber release with the laser.

Dissection near complete. — Dissection near complete (10 of 20)

Here, the microscissors are poised to sever gossamer fibers still connecting the cyst to the underlying vocal cord.

cyst remains un-ruptured during dissection from right vocal cord — Un-ruptured cyst removal! (11 of 20)

Only the final few connections remain to be released.

7mm intact cyst (12 of 20)

The intact cyst measures 7mm (approximately a quarter of an inch).

Mucosa flap after microlaryngoscopy — Mucosa flap (13 of 20)

The flap of mucosa that was peeled off of the cyst.

The flap returned to its original position after microlaryngoscopy — Is the voice affected? (14 of 20)

The flap returned to its original position. Will this vocal cord vibrate again?

despite mild bruising one week after microlaryngoscopy, voice is much improved — Voice is much improved! (15 of 20)

At one week post-op, voice is already MUCH IMPROVED. Closed phase of vibration under strobe light shows expected bruising and mild concavity of the right cord (left of photo).

Vocal cord vibrates with healing bruise — Vocal cord vibrates (16 of 20)

Open phase of vibration with little lateral movement of the right cord (left of photo).

vocal cords with slight bowing, but normal voice — Slight bowing (17 of 20)

At 3 months postop, the patient says his voice is essentially normal. The prephonatory instant under standard illumination at B3 (~ 245 Hz) shows a similar degree of bowing.

Vibrating vocal cords at B3 — Equal vibratory blur (18 of 20)

Phonation under standard light also at B3 shows equal vibratory “blur” of the margin between the two cords.

Reasonable vocal cord closure under strobe light — Reasonable closure (19 of 20)

Closed phase of vibration at B3 shows reasonable closure with the anterior gap appearing to be contributed by both cords equally.

vocal cords showing symmetrical lateral amplitude of vibration under strobe light — Voice returns to baseline (20 of 20)

Again at B3, the open phase with symmetrical lateral amplitude of vibration.

Excision of a Mucus Retention Cyst that Decompresses during Dissection

This man has had slight hoarseness for many years, possibly related to his self-described highly talkative and loud-spoken nature. His voice took a significant turn for the worse soon after a bout of mild laryngitis, and had remained extremely hoarse for many months.

An ENT doctor diagnosed a polyp of his left vocal cord. Instead, this represents a mucus retention cyst. Removal provided dramatic return of clear speaking voice. Seen below is preop, intra-operative sequence, and then the result at 3 months after surgery.

Mucus retention cyst on left vocal cord — Mucus retention cyst (1 of 17)

When viewed at a distance, the left vocal cord lesion (right of photo) could be mistaken for a polyp, especially knowing that this man is a “vocal overdoer.”

white-yellow spherical submucosal mass. — Closer look (2 of 17)

At closer range, the white-yellow spherical submucosal mass is recognizable.

Cyst under narrow band light (3 of 17)

Under narrow band light, additional evidence of the spherical submucosal mass is gained.

Cyst interferes with phonation (4 of 17)

During phonation, marked interference with match and vibratory flexibility of the left cord is seen.

Surgical view of cyst — Surgical view (5 of 17)

Intraoperatively, initial view. Note that the overlying mucosa is gossamer-thin, like a dragonfly’s wing.

Cyst is more distinguished — After infiltration (6 of 17)

After infiltration of lidocaine and epinephrine, partly for hemostasis but even more so for “hydrodissection” and to reveal more clearly where the overlying mucosa is adherent.

Incision is made — Lifting the mucosa (7 of 17)

An incision has been made and the dissector is between the extraordinarily thin mucosa and cyst wall (see dotted line)

Dissection of mucus retention cyst begins — Dissecting cyst from deep attachments (8 of 17)

The dissector is peeling the cyst from its deeper attachments to the vocal ligament.

mucus retention cyst ruptures — Cyst has ruptured and emptied (9 of 17)

As often happens with a mucus retention cyst, the cyst has ruptured, spilling its contents, but the sac has been sufficiently dissected from both overlying mucosa and vocal ligament that its outline is still visible (see dotted line).

Dissection of mucus retention cyst continues — Dissection of empty sac (10 of 17)

Dissection of the decompressed sac from normal cord structures continues…

Gab in mucosa exposed — Flaps retract (11 of 17)

The exceedingly thin flap retracts on itself; there is no good way to stretch it across the empty space where the cyst had been, to meet the lateral flap.

Voice is virtually normal at 3 months (12 of 17)

At 3 months postop, speaking voice can pass for normal and falsetto is even clear. The left cord (right of photo) is still a bit inflamed (prominent capillaries) due to its recent surgical disturbance.

Evidence of vibration, standard light (13 of 17)

Producing voice under standard light, vibratory blurring seems to be present bilaterally.

Vocal cords open at E3 — Open phase at E3 (14 of 17)

Under strobe light, open phase of vibration at E3 (165 Hz).

Vocal cords closed at E3 — Closed phase at E3 (15 of 17)

Closed phase of vibration, also at E3 (165 Hz).

Vocal cords open at A4 — Open phase at A4 (16 of 17)

Open phase of vibration at (falsetto) A4 (440 Hz)

Vocal cords closed at A4 — Closed phase at A4 (17 of 17)

Closed phase of vibration also at A4 (440 Hz).

Removal of Mucus Retention Cyst, Still Intact

Injection in Reinke’s Space — Injection in Reinke’s space (2 of 8)

Reinke’s space (the submucosa) has been infiltrated with 1% lidocaine and epinephrine for hydrodissection and hemostasis.

Incision of mucus retention cyst begins — Incision begins (3 of 8)

The cyst wall and overlying mucosa are both the thickness of a dragonfly wing. The diameter of this cyst is estimated to be 4 mm. It contains retained mucus. The incision must always be longer than the diameter of the cyst.

Removal of cyst (4 of 8)

A left-curved forceps is holding the cyst as it comes away from the cord.

Removal nearly complete (5 of 8)

The cyst is almost free, with a tiny amount of the gossamer overlying mucosa that was tightly adherent.

Cyst is removed (6 of 8)

Only the incision remains, and the mucosa dissected from the cyst retracts. The key to understanding the result will be the postoperative voice and vibratory ability of this operated vocal cord.

post-op closed phase — Post-op (7 of 8)

At the time of this examination, 2 months postoperatively, the patient considers his voice to be normal. Here, he is producing F4 (349Hz) under strobe light (closed phase).

open phase of vibration — Open Phase (8 of 8)

Open phase of vibration, demonstrating full mucosal flexibility.

Removal of Mucus Retention Cyst

infiltration of 1% xylocaine expands tissue — Xylocaine prepares for removal (2 of 7)

After infiltration of 1% xylocaine with epinephrine. This provides “hydrodissection;” it expands the tissue planes; and diminishes bleeding via vasoconstriction.

Removal of Cyst (3 of 7)

At anterior curve of the cyst, left-turning scissors are dissecting at the layer between cyst wall and its attachments.

Removal of Mucus retention cyst — Removal of cyst (4 of 7)

At posterior attachment of cyst, dissection with curbed scissors.

Removal of Cyst (5 of 7)

Cyst dissected nearly free.

4mm Cyst (7 of 7)

Intact cyst, measures about 4mm in diameter.

Example 2