BRANDON C. KU
HISTORY OF PRESENT ILLNESS
The patient is a 6-year-old girl who was well until 2 weeks ago when she began to complain of tenderness on the right side of her neck. This continued for 1 week, after which the parents noticed swelling on the right side of her neck. The swelling and tenderness increased and the patient developed decreased range of neck motion. There was no dysphagia and no upper respiratory infection symptoms. The patient did not have antecedent trauma. She frequently played with the neighbor’s cat but had no known exposure to other animals such as rabbits. A tuberculin skin test, performed 1 week ago, was negative; an anergy panel had not been placed.
The patient had chicken pox 1 month ago. There are no known allergies. She did not receive any prescribed medications. There had been no recent travel.
T 37.8°C; HR 96 bpm; RR 20; BP 106/69 mmHg; Weight 23 kg (75%-90%); Height 44.5 cm (25%-50%)
On general examination, the patient was alert and in no acute distress. She was normocephalic; optic discs were sharp; pupils were equal, round and reactive to light; extraocular muscles were intact; tympanic membranes were gray bilaterally, mobile; nose was without discharge; mouth was without lesions, but mucous membranes were notable for pallor, few petechiae of posterior pharynx. Neck on left side was supple with no prominent adenopathy. There was erythema and swelling that was midline and more prominent just to the left of the midline (Figure 13-1) that was tender to palpation and moved with swallowing. There was no movement with tongue thrust and the mass had well-defined borders. The following were also noted. Lungs: clear lung fields with decreased breath sounds at bases but no rales. Cardiac: regular rate and rhythm; II/IV systolic murmur, no gallop, no rub. Abdomen: soft, non-tender, nondistended; positive bowel sounds × 4; no hepatosplenomegaly. Nodes: no prominent adenopathy. Skin: no rash. Neurologic examination: CN II-XII intact; motor 5/5 throughout; DTR 2+ bilateral on upper extremities and lower extremities; proprioception intact.
FIGURE 13-1. Neck mass in the patient (Case 13-1).
WBC count, 9100/mm3 (56% segmented neutrophils, 34% lymphocytes, 5% eosinophils, 5% monocytes); hemoglobin, 11.2 mg/dL; platelets, 565 000/mm3; ESR, 45 mm/h; PT/PTT, 11.6/24.6 seconds; Barton-ella henselae antibody titers, 1:32; T3, 1.6; TSH, 4.3.
COURSE OF ILLNESS
The patient had evidence of an acute infection. There was tenderness, swelling, and limitation of range of motion. Because of the acute nature of this illness, the size of the mass (>3 cm), and the progression of neck swelling, hospitalization was indicated.
DISCUSSION CASE 13-1
The differential diagnosis in this case included an infected thyroglossal duct cyst. Lymphadenitis was possible, although the location was unusual. Bacteria that typically cause cervical lymphadenitis include Staphylococcus aureus, group A beta-hemolytic Streptococcus, Bartonella henselae, actinomycosis, and oral anaerobes. Cat-scratch lymphadenitis was less likely. The indirect fluorescent antibody (IFA) test has high sensitivity (>95%) and specificity (>98%) for the diagnosis of cat-scratch disease for patients who meet the classic case definition of CSD. Enzyme immunoassay (EIA) testing for IgM and IgG antibodies to B. henselae is also commercially available. A high antibody titer (>1:64) is suggestive of recent infection. However, 2%-6% of asymptomatic cat owners have a low-level positive antibody titer (~1:16 or 1:32). In such cases, paired serologic studies (antibody studies repeated 2 weeks later and performed at the same time as a sample of the serum from the initial test) to detect an increase in the antibody titer may be helpful to confirm the disease; those without any change in the antibody titer when repeated 2 weeks later are unlikely to have an acute infection with B. henselae. The low-level positive in this case was thought to be unrelated to the child’s symptoms.
In the location of this neck swelling, one must also consider thyroid-related masses such as tumors arising from the thyroid or aberrant thyroid gland. Thyroid function studies were normal. The CT scan showed a mass that was larger than clinically appreciated. There was also minimal tracheal deviation that was suggestive of a thyroid nodule. Thus, it was determined that a tissue diagnosis was required without delay.
A neck CT scan revealed a 4 × 5 cm solid neck mass with minimal tracheal deviation. Biopsy of the mass did not reveal lymph node or thyroid tissues; fibrotic changes along with numerous neutrophils, lymphocytes, and monocytes were consistent with an inflammatory process. Bacterial cultures from the mass obtained during a needle biopsy were positive for Eikenella corrodens; smears for acid-fast bacilli (AFB) were negative. The diagnosis was that of a thyroglossal duct cyst that was infected with Eikenella corrodens.
INCIDENCE AND EPIDEMIOLOGY OF THYROGLOSSAL DUCT CYST
Thyroglossal duct cysts are congenital remnants that occur when one thyroid migrates from the base of the tongue to its position in the neck. It occurs anywhere from the base of the tongue through the hyoid bone to just above the thyroid cartilage. Although asymptomatic while dormant, they may become symptomatic when infected.
Thyroglossal duct cysts may be evident at birth or may be dormant for many years until they become infected producing redness, swelling, and pain. The mass of a thyroglossal duct cyst may enlarge to the point of respiratory compromise. Eikenella corrodens is a slow growing organism that has been reported to cause a variety of clinical infections from infected neck masses to brain abscesses, lung infection, bite wound infection, and bone and joint space infections.
The diagnosis is suspected clinically by position and movement with swallowing or protrusion of the tongue. Ultrasound is the preferred imaging modality though CT scan may further delineate the size and location of the mass. The possibility of an aberrant thyroid must be ruled out. A diagnostic clue to the thyroglossal duct cyst is that it moves when the patient is asked to swallow. The cyst may contain elements of thyroid tissue; thus, if the cyst shows solid elements they should be identified with a nuclear scan prior to surgery, lest they be inadvertently removed. Thyroglossal duct cysts are the most common midline lesions.
Eikenella corrodens was isolated in this case. It is an unusual organism but one that should be considered if the patient has active periodontal disease or deteriorated oral health. It is also more common in individuals who are immunocompromised although that was not the circumstance in our patient. Excisional biopsy is the usual method to confirm the diagnosis; the excisional biopsy is typically performed after resolution of the acute superinfection.
The ultimate treatment is surgical. Removal of the cyst and the other remnants of the migration tract are important. This is difficult and detailed surgery that involves surgery in the field of many other important vital structures. Prior to surgery, antibiotic therapy may be helpful in lessening the inflammation and aiding in the postoperative healing process. Antibiotics to cover Gram-positive organism are customary. Eikenella corrodens is a usual Gram-negative organism that probably derives from active periodontal disease. Treatment may be effective with a wide range of antibiotics, however, usually the combination of antimicrobial therapy and surgical draining is required to effect complete recovery.
1. Paul K, Patel SS. Eikenella corrodens infections in children and adolescents: case reports and review of the literature. Clin Infec Dis. 2001;33:545-61.
2. Marra S, Hotaling AJ. Deep neck infections. Am J Otolaryngol. 1996;17:287-298.
3. Sheng WS, Hsueh PR, Hung CC, et al. Clinical features of patients with invasive Eikenella corrodens infections and microbiological characteristics of the causative isolates. Euro J Clin Microbiol Infect Dis. 2001;20:231-236.
4. Cheng AF, Man DW, French GL. Thyroid abscess caused by Eikenella corrodens. J Infect. 1988;16:181-185.
5. LaRiviere CA, Waldhausen JH. Congenital cervical cysts, sinuses and fistulae in pediatric surgery. Surg Clin North Am. 2012;92:583-597.
6. Goff CJ, Allred C, Glade RS. Current management of congenital cysts sinuses and fistulae. Curr Opin Otolarygol Head Neck Surg. 2012;20:533-539.