The authors describe a 34-year-old man who presented with an unapparent swelling on the right preauricular zygomatic region, with progressive limitation of mouth opening and slight temporomandibular joint pain. Based on fine-needle aspiration cytology and radiological investigations, the patient was diagnosed preoperatively as having a possible tenosynovial giant cell tumour (TGCT). Surgical treatment was effective and no local recurrence was observed. Histological and immunohistochemical examination diagnosed an extra-articular diffuse TGCT. The clinical features, histopathological characteristics, imaging modalities, diagnostic methods and treatment of TGCT are discussed and a review of the relevant literature is presented.
Tenosynovial giant cell tumour (TGCT) and pigmented villonodular synovitis (PVNS) are uncommon benign proliferative disorders of the synovium . According to the World Health Organization classification of soft tissue tumours, TGCT is a destructive proliferation of synovial-like mononuclear cells . TGCT commonly affects adults with a slight female predominance . It typically occurs on the extremities, particularly the tendon sheaths of the digits of the hand, where it presents as a well-circumscribed nodule. Intra-articular lesions involve the synovium more diffusely, producing a papillary and nodular growth pattern termed PVNS . PVNS was first described as a yellow–brown tumour-like tenosynovial lesion by J affe et al. in 1941 . The main difference from TGCT is the anatomic location; PVNS is most common in the knee joint (80%) and less common in the hips, shoulders and ankles. PVNS has been reported in patients of all ages, but most commonly it affects adults in their third to fifth decade without sex predilection . TGCT presents in localized and diffuse forms . Localized TGCT is more frequent than diffuse TGCT, representing the most common subset of giant cell tumours. Unlike localized TGCT, diffuse TGCT has a tendency to occur in younger individuals, it presents as a less well-defined soft tissue mass, shows locally aggressive growth and has a high recurrence rate .
In the authors’ extensive literature search, only two cases of diffuse TGCT were reported: in the temporomandibular joint (TMJ) and the skull base . The authors report an additional case of extra-articular diffuse TGCT involving the right infratemporal fossa.
A 34-year-old Chinese man was referred in March 2007 with a 6-month history of an unapparent mass affecting the right zygomatic region and a gradually progressive inability to open his mouth. His history included injury to the right side of his face 3 years previously. On physical examination, an unapparent diffuse swelling was noted in the right preauricular region, his maximum interincisal opening was restricted to 25 mm, and he had a jaw deviation to the left side during mouth opening. No remarkable mass could be palpated intraorally. Contrast-enhanced computed tomography (CT) scans ( Fig. 1 ) revealed an enhancing ill-defined soft tissue mass in the right infratemporal region. The mass, attached to the temporal bone, consisted of mixed high and low attenuation soft tissue extending anteriorly into the right infratemporal fossa and the pterygoid muscles. No signal could be found that the same side of the TMJ and zygomatic bone were influenced. A fine-needle aspiration biopsy (FNAB) of the lesion revealed a histocytic proliferation with numerous multinucleated giant cells, mononuclear cells and hyperplastic pigmentation, and no evidence of overt malignancy before surgical treatment.
Based on these findings, the patient underwent a preauricular infratemporal fossa approach and exenteration of the lesion under general anaesthesia. A right scalp semicoronal incision and zygomatic arch osteotomics were used to expose the lesion. The lesion was red–brown without a fibrous capsule. Careful examination of the TMJ, the coronoid process and the zygomatic arch revealed no evidence of involvement. An intraoperative biopsy was performed for frozen sectioning, which was diagnosed as a possible TGCT. Consequently, the whole soft tissue mass and all the involved structures were removed en bloc and the involved squamous portion of the temporal bone was also curetted. The temporally separated zygomatic arch was then fixed with a mini titanium plate after the removal of the lesion. The patient’s TMJ pain and limited mouth opening were resolved completely. During a 2-year follow-up, no recurrence was observed.
Microscopic examination showed that the lesion predominantly consisted of round to polygonal mononuclear cells with eosinophilic cytoplasm and large round oval nuclei, and mononuclear cell inflammatory infiltration. Haemosiderin-laden foamy macrophages and multinucleated giant cells showing a moderate variation in size, shape, and number of nuclei were focally present. A striking vascular and haemosiderin deposition were also found ( Fig. 2 A). Immunohistochemical staining was used. Most of the multinuclear and mononuclear cells exhibited intense cytoplasmic positivity for vimentin ( Fig. 2 B), CD68 ( Fig. 2 C) and leukocyte common antigen (LCA) ( Fig. 2 D). CD34-positive stained cells appeared to be lining supporting vessels. Immunohistochemical staining for cytokeratin, actin and Ki67 was not expressed in the lesion.
Based on histologic and immunohistochemical findings, the lesion was diagnosed as TGCT, lacking an evident fibrous capsule, and CT scans indicated predominantly extra-articular extension. According to E nzinger & W eiss ‘s classification of soft tissue tumours and the modified classification of the WHO , the lesion should be regarded as an extra-articular diffuse TGCT.
PVNS and TGCT are regarded as a common family of synovial lesions because of their histological similarity. Clinically, both of them are rare, especially in the head and neck. TGCT presents in localized and diffuse forms and occurs most frequently in the fifth or sixth decades of life . Localized TGCT, also called nodular tenosynovitis or giant cell tumour of the tendon sheath, is one of the most common tumours of the hands and feet; 85% of the lesion occurs in the fingers . In comparison, diffuse TGCT, referred to as proliferative synovitis, florid synovitis, extra-articular pigmented villonodular synovitis or pigmented villonodular bursitis, is less common and shows certain clinical differences . The less frequent diffuse TGCT is commonly located in the peri-articular soft tissues, but occasionally these lesions can be purely intramuscular or subcutaneous .
Unlike localized TGCT, diffuse TGCT tends to occur in younger individuals, presents as a less well-defined soft tissue mass, and shows locally aggressive growth and a high recurrence rate. The recurrence rate of giant cell tumour of the tendon sheath in the hand was 16% similar to early published results of 7–27% . The extra-articular form of diffuse TGCT is defined by the presence of an infiltrative soft tissue mass, with or without involvement of the adjacent joint . Purely extra-articular cases of diffuse TGCT are rare and most often arise from the synovium of bursa and tendon sheaths .
Since the first case reported by L apayowker et al. in 1973 , the authors have reviewed 37 cases of PVNS involving the TMJ ( Table 1 ). Diffuse TGCT is rare in the TMJ or skull base. The review results are given in Table 2 . Until now, only two articles have been published in the English literature reporting diffuse TGCT involving the TMJ or skull base . Including the present case, the average age of the patients was 38.3 years (range: 18–63 years). All patients were male and two of them involved the right TMJ; no recurrence was reported among the cases. From the reviewed literature, it could be concluded that the presentation of these lesions involving the TMJ was: a progressive preauricular swelling; pain was not significant; clinical symptoms of temporomandibular disorders such as clicking, limitation of mouth opening, malocclusion, and painful mastication were usually present; other symptoms included hearing loss, otalgia, diplopia, and vomiting; and preoperative diagnosis was usually parotid tumour.
|First author||Published time (year)||Age (years)||Gender (F/M)||Site (R/L)||Follow-up period (months)||Recurrence|
|L apayowker||1973||58||F||L||Not stated||Not stated|
|R aibley||1977||62||F||L||Not stated||Not stated|
|G eiger||1980||50||F||L||Not stated||Not stated|
|C urtin||1983||47||F||L||Not stated||Not stated|
|D awiskiba||1989||32||M||R||Not stated||Not stated|
|S yed||1993||10||F||R||Not stated||Not stated|
|Y u||1997||48||M||R||Not stated||Not stated|
|B emporad||1999||37||M||R||Not stated||Not stated|
|K unz||2003||13||M||R||Not stated||Not stated|
|K im||2004||22||M||L||Not stated||Not stated|
|47||M||L||Not stated||Not stated|
|28||F||R||Not stated||Not stated|
|58||F||R||Not stated||Not stated|
|36||F||R||Not stated||Not stated|
|38||F||L||Not stated||Not stated|
|C ascone||2008||78||M||R||Not stated||Not stated|