An unusual cervical mass

Abstract

Head and neck masses are usually indicative of infectious, neoplastic, or congenital entities. Most head and neck masses are related to local or regional disease, although systemic neoplastic disease can present in the cervical area. We present an interesting case report of a young woman with a neck mass caused by an organism most commonly associated with sexually transmitted infections, and not with the more common causes of cervical head and neck masses.

Case Presentation

A 19-year-old, otherwise healthy, non-smoking female was referred for ear, nose, and throat (ENT) consultation by a local walk-in clinic due to a right-sided neck node that had been present for about 5 weeks. She denied any recent illness or infection, cat scratches, travel, or dental disease. Further questioning revealed recent weight loss and daily night sweats.

Her medical history was otherwise non-contributory. She had no allergies, and medications only included oral contraceptive pills. She had been sexually active with a few male sexual partners over the past year and was regularly tested for sexually transmitted infections, which always yielded negative results. Ultrasound revealed several right-sided neck nodes, the largest being 3.0 × 3.7 cm in the area of the right submandibular triangle. The radiographic differential included infection or inflammation, lymphoma, or metastatic disease.

A blood test showed normal hemogram and differential, normal monospot, but slightly elevated alanine aminotransferase (ALT). The ENT clinical exam was negative except for the easily palpated large right jugulodigastric neck mass. Fine needle aspiration (FNA) was done in-office and was reported as likely reactive lymph tissue.

In view of the FNA results and the symptoms the patient was experiencing, the decision was made to excise the node. She underwent aerodigestive tract endoscopy and open biopsy of the node. The procedure was uneventful, and she was discharged home the same day.

Three days post-op, the patient complained of swelling and redness at the surgical site. Ultrasound showed a 3.5 × 2.9 cm collection of fluid present and an oral cephalosporin was ordered, but the swelling continued to increase. The patient was admitted to hospital for intravenous cefazolin and close monitoring. FNA was performed of the post-operative collection, and frank pus was obtained and sent for culture and sensitivity. Over the following 48 hours, the swelling continued, and it was apparent that open drainage of the abscess would be required. A pre-operative computed tomography (CT) scan showed the presence of an abscess with myositis of the sternocleidomastoid and platysma muscles. Numerous nodes were also identified in the right jugulodigastric and mid-cervical area. Ceftriaxone was substituted for cefazolin, and open neck drainage was carried out under general anesthesia.

The intra-operative surgical findings revealed an abscess with gross necrosis of the deep neck tissues and muscles. Cultures were taken once again and the wound thoroughly irrigated with povidone-iodine and saline. During the closure, a Penrose drain was placed. Intravenous metronidazole was added to the ceftriaxone therapy for extra anaerobic coverage. Post-operatively HIV serology and a tuberculosis (TB) skin test were done, both of which were negative.

Surgical pathology findings showed gross tissue necrosis and lymphoid infiltrates. Fungal stains were negative for hyphae, and additional acid-fast bacilli and gram staining did not show any organisms initially. Flow cytometry studies were negative for lymphoma but suggested follicular hyperplasia and progressive transformation of the germinal centres.

After 48 hours, the hospital microbiology lab reported the presence of tiny colonies on horse blood agar incubated aerobically in 5% CO₂ from both the FNA of the post-operative collection and the intra-operative cultures from open drainage of the post-operative abscess. Gram staining of the colonies failed to distinguish any organisms. A sample was sent to the Public Health Ontario Laboratories reference microbiology lab. Matrix-assisted laser desorption/ionization (MALDI) identified Mycoplasma hominis. Cultures done at the sexually transmitted infection bacteriology laboratory revealed Ureaplasma urealyticum as well as a large colony variant Mycoplasma species, which was identified by 16S rRNA PCR as M. hominis.

The patient was treated with a 1-month course of levofloxacin and her neck swelling dramatically improved, and her systemic symptoms resolved.

Discussion

U. urealyicum and M. hominis, types of genital mycoplasmas, are part of the Mollicutes class. Mycoplasmas have the smallest genome of any known self-replicating organism. They lack a cell wall and are thus osmotically fragile (1). Complex growth media is generally required for cultivation in vitro, although M. hominis grows slowly on blood agar, producing non-hemolytic colonies with a “fried-egg” appearance. Ureaplasmas can hydrolyze urea for energy production.

In a study of normal college men, ureaplasmas were present in the urethra in 29% of participants whereas M. hominis was present in only 7% (1). Women may be more susceptible to colonization with M. hominis, as the rate of colonization increases more rapidly with sexual experience in women than in men (2). A study by Mufson determined that about 3% of healthy adults have colonization of the oral or respiratory tract by M. hominis (3). Infections that have been linked to U. urealyticum include nongonococcal urethritis, pelvic inflammatory disease (PID), postpartum fever, preterm delivery, and neonatal lung disease. Infections linked to M. hominis include PID, chorioamnionitis, postpartum and postabortal fever, pyelonephritis, septicemia, central nervous system infections, post-operative wound infections, joint infections, and upper and lower respiratory tract infections.

These organisms have no cell wall, so they are not susceptible to beta-lactam antibiotics. Ureaplasmas are susceptible to macrolides and tetracycline, although 10%–15% resistance to tetracycline has been reported (1). M. hominis is resistant to macrolides and susceptible to tetracycline. Quinolones are active against M. hominis and ureaplasmas (1).

To our knowledge, this is the first report of U. urealyticum and M. hominis causing a neck mass. It is notable that our patient was immunocompetent. A case of a parapharyngeal abscess caused by M. hominis following an Epstein–Barr virus infection has been previously described (4). We hypothesize that, in our case, orogenital sexual contact resulted in colonization of the oropharynx with these organisms, with subsequent dissemination to the cervical lymph nodes. It is possible this was a polymicrobial infection with other oral organisms, such as anaerobes and streptococci, and the pre-treatment with ceftriaxone and metronidazole inhibited the growth of these organisms in culture. Alternatively, given that M. hominis has been implicated in post-operative infections (5), this could be the route of infection in our case.

In summary, we describe a case of a neck mass caused by M. hominis and U. urealyticum, two organisms not previously described in this context. Our patient was treated with surgical drainage of the collection and quinolone therapy.

Competing Interests:

The authors have nothing to disclose.

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Funding:

No funding was received for this work.

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This article has been peer reviewed