An open epidermoid cyst can be seen when an epidermoid cyst spontaneously ruptures, but still retains some of the accumulated keratin; in this case, the cyst’s outline may be more subtle, and usually assumes an oval shape with the long axis oriented anteriorly and posteriorly. An open cyst may also produce a mottled appearance.
Photos of open epidermoid cyst:
Capillary ectasia and white submucosal abnormality (1 of 3)
Left vocal cord (right of photo) has not only overlying capillary ectasia, but a white submucosal abnormality.
Open cyst (3 of 3)
Closer view. While an intact epidermoid cyst has a distinct outline, an open cyst develops a more mottled appearance. It may leak intermittently from a tiny dimple or sulcus which is sometimes seen at very close range.
Hoarse voice (1 of 4)
A young woman with a history of repeated loud cheering during athletic activities, to the point of hoarseness. She has a sulcus of the right cord (left of photo), and an open cyst of the left (right of photo). Openings from sulcus and cyst are indicated by dotted lines.
Cyst + sulcus (2 of 4)
Narrow band light. The lateral lip of a sulcus is often bordered by a prominent capillary as seen here. An open cyst assumes an elliptical shape in the anteroposterior direction. It fails to empty completely because the opening draining it is smaller than the diameter of the cyst.
Margin swelling (1 of 6)
Breathing position of the vocal cords of a very hoarse actor. Note the margin swelling of both sides. The white material on the left vocal cord (right of photo) is keratin debris emerging from an open cyst. Find the sulcus of the right vocal cord (left of photo) which is more easily seen in the next photo.
Narrow band light (2 of 6)
Further magnified and under narrow band light. The right sulcus is within the dotted outline. Compare now with photo 1.
Open phase, strobe light (3 of 6)
Under strobe light, open phase of vibration at A3 (220 Hz). The full length of the cords participate in vibration.
Closed phase, same pitch (4 of 6)
At the same pitch, the closed phase again includes the full length of the cords.
Segmental vibration (5 of 6)
At the much higher pitch of C5 (523 Hz) a “tin whistle” quality is heard and only the anterior segment (at arrows) is opening for vibration. The posterior opening is static and not oscillating, as seen in the next photo.
Closed phase (6 of 6)
The closed phase of vibration involves only the tiny anterior segment of the vocal cords, at the arrows. The posterior segment is not vibrating and is unchanged.