Correspondence

CPAP Cyst

N Engl J Med 1993; 328:1357May 6, 1993

Article

To the Editor:

Nasal continuous positive airways pressure (CPAP) is a standard treatment for the sleep apnea syndrome1. The reported side effects are not major: nasal dryness, epistaxis, extension of respiratory infections to the middle ear or sinuses, and allergic reactions to the mask1-4. We describe a patient in whom a thyroglossal cyst developed shortly after nasal CPAP was begun.

A 56-year-old woman with a long history of diurnal hypersomnolence, respiratory pauses during sleep, and loud snoring was found to have obstructive sleep apnea syndrome on polysomnography. She had 90 episodes of apnea or hypopnea per hour of sleep, with marked decreases in the oxyhemoglobin saturation and fragmentation of her sleep. The findings at nasal, pharyngeal, and laryngeal examination were normal. Application of nasal CPAP at a level of 8 cm of water abolished the apnea, normalized sleep, and was well tolerated by the patient, who reported that she slept as she had not been able to for years. In the ensuing eight days, however, a painless tumor developed in the anterior region of the neck, without fever or signs of local inflammation. The patient recalled that she had always had a small, painless tumor in the same area, although it had not been noticed during the initial clinical examination. Computed tomographic scanning showed a prelaryngeal cyst 2 by 4 cm (Figure 1Figure 1Anterior Area of Neck on Computed Tomographic Scanning.), which was then surgically removed. Pathological examination identified a colloidal cyst embedded in a translucent membrane, coated with a ciliated cylindrical epithelium with some squamous metaplasia and some thyroid follicles -- all characteristic of a thyroglossal cyst. Nasal CPAP was discontinued. A polysomnogram obtained three months later again documented many episodes of apnea. After CPAP was restarted, there were no further problems.

The temporal relation between the initiation of CPAP and the sudden rare appearance of a thyroglossal cyst in an adult5 suggests a causal relation in our patient. An increase in intrapharyngeal pressure by nasal CPAP most likely forced air or saliva through a persistent thyroglossal duct, with resultant hypersecretion of its cells. Bacteria from the upper airway could also have been introduced into the cyst, although there was no clear evidence of inflammation. Physicians should examine the neck routinely before prescribing nasal CPAP for patients with sleep apnea.

Juan J. Poza-Aldea, M.D.
Antonio Morello, M.D.
Joan Santamaria, M.D.
Hospital Clinic i Provincial de Barcelona, 08036 Barcelona, Spain

5 References

1. 1

   Sullivan CE, Grunstein RR. Continuous positive airways pressure in sleepdisordered breathing. In: Kryger MH, Roth T, Dement WC, eds. Principles and practice of sleep medicine. Philadelphia: W.B. Saunders, 1989:559-70.
   

2. 2

   Hoffstein V, Viner S, Mateika S, Conway J. Treatment of obstructive sleep apnea with nasal continuous positive airway pressure: patient compliance, perception of benefits, and side effects. Am Rev Respir Dis 1992;145:841-845
   Web of Science | Medline

3. 3

   Rolfe I, Olson LG, Saunders NA. Long-term acceptance of continuous positive airway pressure in obstructive sleep apnea. Am Rev Respir Dis 1991;144:1130-1133
   CrossRef | Web of Science | Medline

4. 4

   Strumpf DA, Harrop P, Dobbin J, Millman RP. Massive epistaxis from nasal CPAP therapy. Chest 1989;95:1141-1141
   CrossRef | Web of Science | Medline

5. 5

   Androulakis M, Johnson JT, Wagner RL. Thyroglossal duct and second branchial cleft anomalies in adults. Ear Nose Throat J 1990;69:318-322
   Medline