Abstract
Central giant cell tumour is a benign locally aggressive lesion. It is considered as a rare entity in the head and neck region. Although Surgical resection remains the treatment of choice, its coupled with increase morbidity and recurrence.
Here we present a case of elderly patient with infra temporal CGT treated with Denosumab and showed significant improvement in symptoms and radiological findings.
Highlights
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Central giant cell tumour is a benign locally aggressive lesion. It is considered as a rare entity in the head and neck region.
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Although Surgical resection remains the treatment of choice, its coupled with increase morbidity and recurrence.
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Here we present an elderly patient with infra temporal CGT treated with Denosumab, showed significant improvement in symptoms and radiological findings.
1
Introduction
Giant cell tumour of bones (GCTBs) is a rare condition, especially of the cranial and facial bones, approximately 2% of GCTBs involve the head and neck [ ]. Occurrence in the axial skeleton is often associated with increased morbidity because of locally aggressive infiltration of critical structures and the associated difficulty of complete tumour resection, particularly compared with resection of GCTBs of the appendicular skeleton where it is more common and typical site for such tumour [ ]. Nevertheless, surgery remains the treatment of choice for GCTBs, including those in the skull, with en-bloc or wide local excision portending the lowest risk of recurrence and best clinical outcomes [ , ]. Although much research has focused on GCTBs involving the long bones, only few reports on GCTBs involving the infratemporal region of the skull base.
To the best of our knowledge, this is the only reported case of an elderly patient with infra temporal (GCTBs) treated with Denosumab. Here, we report the clinical presentation, radiographic findings, medical management, and PET scan follow up.
2
Case report
A 70-year-old female presented to the department of craniomaxillofacial surgery, Hamad medical corporation, Doha, Qatar, complaining of a two years history of right-side facial pain. The patient reported having sever pain (NRS = 8) involving the right side of the jaw, ear and head that is most intense in the morning and continuous throughout the day.
The patient is known case of diabetes mellitus II, dyslipidaemia, and osteoarthritis of the knee joints on regular medical treatment. The patient had no known allergies or habits.
Clinical assessment of the patient showed normal facial appearance and symmetry. Head and neck examination showed tenderness over the temporomandibular joint and preauricular region on the right side. Normal TMJ function with no clicking or crepitation of both sides apart from increase in pain on extreme mouth opening. Extra oral and intra oral assessment of the muscle of mastication showed right side mild rigidity and tenderness mostly related to right side lateral pterygoid muscle. The assessment of teeth and supporting tissue was unremarkable. An orthopantomogram was done which did not show any pathological changes related to the condyle jaw or teeth.
The patient was diagnosed as a case of temporomandibular joint disorder and was started on conservative therapy with pain medication and night guard. During the follow up appointment the patient reported worsening of symptoms and decrease in mouth opening on conservative therapy so and MRI of TMJ was requested.
The MRI showed normal TMJ architecture and normal disc position. It also showed right sided infratemporal region mass that is lobulated centered medial to lateral pterygoid causing some fatty atrophic changes. It measures 25 mm in craniocaudal dimension, 18 mm in width and 15 mm in AP dimension. The lesion demonstrates peripheral smooth low signal rim on the inferior aspect. In the cranial aspect, there is diffuse irregular sings of calcification extending cranially and abutting the medial and anterior aspect of the articular eminence ( Figs. 1 and 2 ).
Ct scan was done which showed lesion at the right infratemporal fossa epicentered medial to the lateral pterygoid muscle which appears of intermediate density and shows peripheral calcification along its lateral and superior aspects. The lesion is seen abutting the inferior aspect of the right sphenoid bone with evidence of erosions/rarefaction and scalloping. The lesion is encroaching upon right lateral parapharyngeal space causing blurring of the fat plane within vicinity of the foramen ovale but no evidence of widening ( Fig. 3 ).
The case was discussed in multidisciplinary team and planned for image guided core biopsy and PET CT scan. The biopsy showed osteoclastic rich giant cell lesion suggestive of central giant cell tumour vs brown tumour. Workup for possibility of hyperparathyroidism was ruled out by laboratory tests. Pet scan showed markedly hypermetabolic lesion in the right inferior temporal fossa abutting the inferior aspect of the sphenoidal sinus and extending to the parapharyngeal region findings is highly suspicious for malignancy with SUV of 43.6 ( Fig. 4 ).
Due to the patient age and co morbidities along with extensive surgical intervention it was decided to start the patient on denosumab which is a human monoclonal antibody for the treatment of osteoporosis, treatment-induced bone loss, metastases to bone, and giant cell tumour of bone.
Prior to the initiation of denosumab, the patient underwent dental clearance as per the protocol established by the hospital to reduce the risk of medication related osteonecrosis of the jaw.
It was decided that the patient will receive 120mg of denosumab once a week for three weeks. Patient was assessed 4 weeks after the initial dose and showed complete settling of the symptoms. Follow up pet scans showed regression of the tumour size and SUV reduction from 43.6 in the first PET scan to 36 in the second scan done after 4 months to 30 and reduction of SUV to 30/29 in the final pet scan done one year from the initial scan ( Figs. 5 and 6 ). The last MRI done showed decrease in the size of the tumour to 7mm from the first MRI done (25mm) ( Fig. 7 ).
