Volume 5, Issue 4 , Pages 149-151, December 2010
A case of perithyroidal actinomycosis in a child with pyriform sinus fistula
Article Outline
Abstract
Although actinomycosis may occur anywhere in the body, the most common site of this infection is the head and neck region. Actinomyces, the usual cause of actinomycosis, is a commensal bacterium with low pathogenicity that is a normal resident in the oral cavity, thus odontogenic injury is a common antecedent event. Therefore, cervicofacial actinomycosis commonly occurs in the mandibular area, submandibular gland, and tongue in order of decreasing frequency.
The authors encountered a case of a child with a history of slowly progressing swelling in the left side of the lower neck and no history of oral or odontogenic trauma. A pyriform sinus fistula found in this patient could be the unusual root of the cervicofacial actinomycosis occurring in the perithyroidal region, via a direct connection between the site of infection and the upper aerodigestive tract.
Keywords: Actinomycosis, Pyriform sinus fistula
1. Introduction
Actinomycosis of the head and neck region is uncommon. This infection is caused by the organism Actinomyces, a gram-positive anaerobic bacterium that is a normal resident of the oral cavity and the respiratory and digestive tracts. Because Actinomyces is unable to invade healthy tissue, oral or dental trauma that disrupts the normal mucosal barrier is the most common antecedent event leading to cervicofacial actinomycosis [1]. Therefore, actinomycosis of the head and neck occurs predominantly in upper portion of neck, such as the submandibular and parotid glands and the mandible [2].
Pyriform sinus fistula is also an uncommon disease entity but should be considered in differential diagnosis in children with perithyroidal or recurrent cervical abscesses, especially on the left side of the neck [3]. Although distinction between third and fourth branchial anomaly is not possible with only clinical and radiologic findings, pyriform sinus fistula is generally considered as fourth branchial anomaly when the pharyngeal opening is near the apex of the pyriform sinus [3], [4].
To date, there have been no reports implicating pyriform sinus fistula in the etiology of cervicofacial actinomycosis. In this report, an unusual case of perithyroidal actinomycosis occurring in a child with left side pyriform sinus fistula is presented, along with a brief review of cervicofacial actinomycosis.
2. Case report
A 9-year-old boy presented with a 2-week history of slowly progressing swelling in the left side of the neck. He had no history of fever, chills, or sore throat. He had good dental hygiene and no history of dental manipulation or antecedent trauma of the oral cavity and neck. There was no significant past medical or surgical history.
On physical examination, a mass of approximately 4
cm in size was palpable on the left side of the neck between the trachea and the lower third of the sternocleidomastoid muscle. The mass was firm and mildly tender, with erythematous overlying skin. There was no cervical lymphadenopathy in the upper or right neck.
The clinical impression based on the patient's history and physical examination was of a deep neck infection. The patient's work-up revealed a leukocyte count of 13,500 and elevated level of ESR. A computed tomographic (CT) scan of the neck revealed an ill-defined lesion with inner central necrosis and rim enhancement in the left perithyroidal area, suggesting infectious or tuberculous lymphadenitis (Fig. 1A). Fine needle aspiration cytology recovered only neutrophils and lymphocytes. The patient was admitted and was treated intravenously with ceftriaxone, but in spite of antibiotic treatment over the course of a full week, neck swelling and tenderness increased. Follow-up neck CT showed a marked increase in size of the ill-defined soft tissue mass, accompanied by abscess formation (Fig. 1B).
Fig. 1.
(A) Computed tomography showing an ill-defined lesion with inner central necrosis and rim enhancement in the left perithyroidal area. (B) Follow-up computed tomography showing marked increase of the ill-defined soft tissue mass with abscess formation. (C) Postoperative computed tomography showing marked improvement after incision and drainage.
Because of the lack of improvement with antibiotics, incision and drainage was performed. At surgery, pus was sent to the laboratory for anaerobic and aerobic cultures, and granulomatous and necrotic tissue within the lesion was curetted and taken for microscopic examination. The surgical site was then copiously irrigated and a Penrose drain was placed. After incision and drainage was accomplished, hypopharyngoscopy was performed to evaluate the left pyriform sinus because of the lesion's location in the left perithyroidal area. During this procedure an opening was found in the apex of the left pyriform sinus, and trichloroacetic acid was applied in order to obliterate the opening by circumferential chemocauterization, and to prevent the recurrence eventually (Fig. 2A) [4].
Fig. 2.
(A) Hypopharyngoscopy revealing the opening at the left pyriform sinus apex (arrowhead). (B) Barium swallow showing an irregular tract extending from the left pyriform sinus (arrowhead).
The anterior neck erythema and induration decreased dramatically after surgery (Fig. 1C). Histology revealed acute and chronic inflammation with abscess formation and sulfur granules, suggesting actinomycosis (Fig. 3). Cultures were negative. The antimicrobial therapy was changed to intravenous ampicillin and continued for 3 weeks, and after discharge the patient was treated with oral amoxicillin to prevent recurrence.
Fig. 3.
Histologic photography showing a typical sulfur granule (hematoxylin–eosin stain, original magnification 100×).
A postoperative barium swallow revealed an irregular tract extending from the left pyriform sinus (Fig. 2B). However, the parents refused further treatment for pyriform sinus fistula and patient was lost to follow-up.
3. Discussion
Actinomycotic infections of the cervicofacial region are uncommon, with approximately a single case reported annually at most major medical centers [5]. Therefore, diagnosis is often missed or delayed due to general unfamiliarity with the disease and because of its outward similarity to other conditions such as malignant or granulomatous diseases.
Because the causative microorganisms of actinomycosis, especially Actinomyces israelii, are normal residents of the oral cavity with low pathogenicity, odontogenic injury such as maxillofacial trauma, dental manipulation, or dental caries generally precedes infection. Therefore, cervicofacial actinomycosis mainly occurs in adults with poor oral or dental hygiene and commonly involves the area adjacent to the oral cavity, including the submandibular space, cheeks, parotid gland, tongue, and so forth [1], [6].
There has been previous case reports of actinomycotic abscess of the thyroid gland in children and adult. However, communication between the pyriform sinus and neck was not shown in any of these cases [7], [8]. There has also been numerous cases of recurrent neck abscesses in patients that was later shown to have pyriform sinus fistulas, although once again actinomycosis was not shown in any of these cases [3], [4].
Physical findings for actinomycosis are nonspecific, but a hard, palpable and tender mass with an indolent course is the most common finding. The overlying skin may show violaceous color due to secondary venous congestion. Necrosis, granuloma, abscess and eventually fistula can form with the progression of infection.
CT and MRI findings for cervicofacial actinomycosis include an ill-defined, infiltrative soft tissue mass with a low-attenuating center and an inflammatory change in the adjacent soft tissue, as in the present case [9]. Positive cultures are very difficult to obtain due to lack of proper culture conditions, very slow growth of organism, previous use of antibiotics [2], [6]. Diagnosis is often successfully made only through histologic identification of the characteristic sulfur granules. Thus early opening biopsy is often required to diagnose the actinomycotic infection quickly.
Long-term antibiotic therapy and surgical debridement are the mainstays of treatment for actinomycosis. Penicillin is the drug of choice and is usually administered for from 2 to 12 months, although short-course treatment may cure uncomplicated cervicofacial actinomycosis [1]. Oral amoxicillin, tetracycline, erythromycin, and clindamycin have also been shown to be effective for actinomycosis [6].
Authors urge the inclusion of cervicofacial actinomycosis in the differential diagnosis of chronic inflammatory masses unresponsive to empirical antibiotic therapy, and advise consideration of early surgical management with biopsy for avoiding delays in proper diagnosis. We also recommend that direct hypopharyngoscopy or barium swallows should be done for all patients with actinomycotic infection below the level of cricoid cartilage while careful examination of oral cavity should be done in upper cervicofacial actinomycosis. In conclusion, pyriform sinus fisula may be the possible infectious route for cervicofacial actinomycosis, especially in the lower cervical region.
References
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PII: S1871-4048(09)00046-X
doi:10.1016/j.pedex.2009.08.002
© 2009 Elsevier Ireland Ltd. All rights reserved.
Volume 5, Issue 4 , Pages 149-151, December 2010
