Abstract
We present here the case of a three-year-old girl with a maxillary myxoma misdiagnosed as tuberculosis (TB). She was referred to our TB clinic with fever for seven months and swelling of the left cheek and a positive Mantoux test. Her mother was also on treatment for TB lymphadenitis. The child had been commenced on anti-tuberculous therapy (ATT) two months before, and because of its unusual location of the swelling, we did a Caldwell-Luc procedure and a white gelatinous tissue was obtained which, on histopathological examination, revealed myxomatous tissue and no granulomas. TB culture was negative. The patient was then referred to the ENT department for surgical excision. We present this case, as not all swellings with positive Mantoux test or contact with TB are TB and it is essential to have a tissue diagnosis of TB to prevent unnecessary treatment with ATT drugs.
Keywords
The paediatric population often presents with facial swelling or mass which may be caused by a range of congenital and acquired infections. 1 Tuberculosis (TB) that manifests with the involvement of the oral cavity is one such rare presentation, with an occurrence of 0.05–5% of total TB cases. 1 Extra-oral involvement of the cheek involving sinuses, tracts and ulceration (most common manifestation) has been reported in the past but its presentation as a swelling remains extremely rare. They occur secondary to underlying TB and primary cases are rare usually involving disruption of oral mucosa which is necessary for the microorganism to become pathogenic. 2 Such an atypical presentation poses a diagnostic challenge to the physician 1 since it may be confused with other differentials for swelling of the cheek such as a myxoma. Myxomas are benign and slow-growing, but locally aggressive tumours of ecto-mesenchymal origin. They are relatively rare 3 and are of two types: (1) involving facial bones, odontogenic and osteogenic; and (2) involving soft tissues, namely perioral soft tissue, the parotid gland, ear, and larynx.4–6 They remain asymptomatic and displacement of teeth, pain and paraesthesia are rare thus allowing the tumour to reach a considerable size before diagnosis.4,7 The tumour is usually seen in the second or third decades of life and is uncommon in children.5,7
Case report
A three-year-old girl presented to our paediatric TB clinic with a fever present for the previous 7–8 months with a left cheek swelling which was tender on palpation. She had received antibiotics during the initial 2–3 months based on a diagnosis of sinusitis. Her mother was diagnosed as having TB lymphadenitis and had been taking ATT for four months. The 5TU dose Mantoux was positive (14mm). She had also received ATT for the previous two months. However, she continued to have intermittent fever and her parents noticed a gradual increase in swelling of her left cheek. Her erythrocyte sedimentation was 90 mm/h. On presentation, apart from the check swelling, general examination was unremarkable. Her chest radiography was normal. An ultrasound scan of the cheek showed a hypo-echoic lesion of 2.7 × 1.9 cm in the left infra-orbital area. A computed tomography (CT) scan of the paranasal sinus showed chronic inflammatory destruction of the walls of maxillary sinus with a non-enhancing lesion within the sinus, eroding the intra-orbital and intra oral walls (Figure 1).
Histopathology showing a hypocellular benign lesion with spindle cells with myxoid/myxohyaline stroma suggestive of myxoma of maxillary sinus.
She underwent a Caldwell-Luc maxillary antrostomy, from which white gelatinous tissue was obtained. Histopathological examination revealed this to be a hypocellular benign lesion with spindle cells with myxoid and myxo-hyaline stroma suggestive of myxoma of maxillary sinus (Figure 2). Her ATT was stopped. TB culture from the biopsy tissue was also negative. She was then referred to ENT colleagues for surgical excision of the tumour.
CT scan showing chronic inflammatory destruction of walls of left maxillary sinus with intra-sinus non-enhancing lesion with erosion of intra-orbital and intra-oral plate.
Discussion
Approximately one million people worldwide are misdiagnosed each year as having TB but happen to suffer from other similar disorders, such as chronic pulmonary aspergillosis, HIV with lymphoma or pneumonia, as well as other conditions. False positives also confuse the diagnosis if a patient has received a BCG vaccination. 8 In our case, a maxillary myxoma, though not unreasonably, was misdiagnosed as TB, based on a close family contact and a positive tuberculin skin test.
A myxoma is a true neoplasm composed of either stellate, rounded, angular and sometimes spindle-shaped cells in a myxoid stroma containing mucopolysaccharide with delicate reticulin fibres. It is benign in nature and has never been proven to undergo malignant transformation or metastasis. 7 The gelatinous nature enhances its ability to infiltrate. It is more predominant in women 6 and is rarely seen in individuals aged < 10 years or > 50 years.4,7 Lesions of the maxilla are aggressive but in the maxillary sinus fill it asymptomatically. Hence the myxoma may remain unnoticed. 6 Advanced lesions are accompanied by pain, paraesthesia, facial asymmetry, displacement of teeth, root resorption and ulceration. 7 Myxomas, particularly in the heart, secrete many cytokines and inflammatory mediators (interleukin-6, interferon-γ, TNF-α) with pyrexia effect. In our patient, fever erroneously supported the diagnosis of TB and the swelling was non-tender. 9
Methods such as conventional radiography and CT are helpful in the detection of myxoma and allow estimation of the size, extent and margins of the tumour. 7 The final diagnosis is made with histopathological examination.4,5 Treatment includes enucleation, simple surgical curettage, peripheral osteotomy, surgical resection of involved bones and radical resection of aggressive tumours depending upon the size, nature and behaviour of the tumour.3,5
Owing to a close resemblance between a maxillary myxoma and TB of the cheek, it becomes essential to separate these rare conditions from each other, as shown in our case. In a case of suspected TB of the cheek before inadvertent ATT administration, a definitive diagnosis can be arrived at with the help of excisional biopsy for tissue diagnosis and culture examination for detection of bacteria. Treatment includes dissection of the mass with total excision. 2 A characteristic swelling associated with lymphadenitis and other related TB lesions present in the body will, however, usually suggest TB 1 rather than a myxoma.
Conclusion
A clinical diagnosis of tuberculosis of TB is fraught with uncertainty. Bacteriological confirmation or histopathological diagnosis at best is essential to confirm the diagnosis; failure to respond to TB treatment must be investigated further.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.