Here, we report the case of recurrent swelling and pain in the proximal interphalangeal joint of the left ring finger, which was later diagnosed as a localized tenosynovial giant cell tumor in a young adult female. The first presentation was at the same anatomical site four years prior. Examination at presentation showed a firm skin-colored nodule in the volar aspect of the left ring finger. The swelling was seen to be partly attached to underlying structures and was non-tender. After a careful physical examination and plain radiograph imaging of the hand, the two differential diagnoses considered were tenosynovial giant cell tumor and ganglion cyst. A surgical excision was performed, and histopathologic evaluation showed features consistent with a tenosynovial giant cell tumor, localized type. The resection margins were clear of tumor. The patient had no intraoperative or postoperative complications. Postoperative physiotherapy was recommended. No recurrence was seen after postoperative surgical follow-up for one year. This report highlights the importance of histopathologic evaluation and confirmation of clear surgical margins in the management of tenosynovial giant cell tumors. In recurrent cases, surgical re-excision with clear margins provides good clinical outcomes. Before surgical excision, patients should be informed about the biologic nature of the lesion and the high risk of recurrence. The management modalities to prevent recurrence and the need for long-term follow-up should also be discussed with the patient.

Giant-cell tumors of the tendon sheath (GCT-TS) are relatively common benign tumors that arise in close proximity to joints and tendons. Malignant GCT-TS are extremely rare. Surgery with wide resection remains the cornerstone for treating malignant giant-cell tumors of the tendon sheath especially in large tumor cases.

OBJECTIVE: Many patients with amyloidosis undergo carpal tunnel release (CTR) before amyloidosis diagnosis and before developing cardiac or other serious disease manifestations. The purposes of this study were to examine if our patient population had a similar prevalence of positive amyloidosis diagnoses to that in prior studies and to describe the results of implementing a screening program for amyloidosis.
METHODS: We retrospectively reviewed the biopsy results and subsequent interventions for all patients who underwent screening tenosynovial biopsy during CTR from March 2020 through December 2021. Amyloid screening was offered to patients who met the criteria for increased risk of disease using an appropriateness screening algorithm.
RESULTS: Seventy-five (48%) of 156 patients who underwent CTR met the eligibility criteria for amyloidosis testing. Of the 62 patients who agreed to undergo tenosynovial biopsy, 14 had amyloid-positive biopsy specimens (10 men and 4 women). All patients with positive tenosynovial biopsies had bilateral carpal tunnel syndrome and wild-type transthyretin amyloid subtype. One patient was diagnosed and started treatment for otherwise asymptomatic cardiac amyloidosis.
CONCLUSIONS: The incidence of amyloid-positive tenosynovial biopsy results from CTR was 22.5% in patients using the criteria from an appropriateness screening algorithm, which was higher than previously reported. Implementation of a screening program for patients undergoing CTR requires a multidisciplinary approach and may result in early diagnosis and lifesaving interventions for patients with amyloidosis.
METHODS: Differential diagnosis/symptom prevalence study, II.

Tenosynovial giant cell tumor (TGCT) is a rare entity that is not well described in the neurosurgical literature. We present a case of a 37-year-old woman with a diffuse subtype TGCT of the cervical spine, affecting the left cervical 6-7 facet joint, with co-incidental cervical trauma. Initial management consisted of subtotal resection and cervical stabilization with cervical 6 to 7 laminectomy, and cervical 4 to thoracic 2 posterior instrumented fusion. Gross total resection was achieved at a later date with a plan for postoperative radiation to prevent a recurrence. The patient was lost to follow-up for radiation treatment and returned 2.5 years later with minor symptoms and recurrence at the surgical site.

Tenosynovial giant cell tumours of the temporomandibular joint (TMJ) are extremely rare, particularly the subset of chondroid tumours. They can be broadly divided into localised and diffuse types, of which we know of only 116 reported cases in the TMJ. Rarer still are the subset of chondroid tenosynovial giant cell tumours, of which we know of only 30 cases that have affected the TMJ. We present a case that involved the TMJ, and include a discussion of its management.

Synovial lipoma arborescens is a rare and benign fatty proliferative lesion of the synovium that is most commonly seen within the suprapatellar pouch of the knee, but increasingly reported to involve tendon sheaths, including those of the ankle. We present the third known case of tenosynovial lipoma arborescens isolated to the peroneal tendon sheath without ankle joint involvement. To our knowledge, this is the first to report this entity utilizing a unique combination of radiographic, sonographic, and MR imaging, along with intraoperative and histologic correlation. Knowledge of this case is important when interpreting radiographic or sonographic images of this condition to raise the possibility of the rare entity of lipoma arborescens involving the peroneal tendon sheath.

Tenosynovial chondromatosis is a benign chondrogenic metaplasia of extra-articular synovial tissue. The most common locations for tenosynovial chondromatosis to develop are the hands and feet. The condition has rarely been reported in children. We present a case of tenosynovial chondromatosis of the flexor hallucis longus in a 17-year-old girl. The presentation was unusual not only due to the location and young age of the patient but also the absence of any palpable mass on physical exam and complete lack of calcification of the cartilage bodies. Initial diagnosis was made by MRI. The patient underwent tenosynovectomy with an excellent postoperative recovery at 6-month follow-up. Histopathology confirmed the diagnosis of tenosynovial chondromatosis.

Tenosynovial giant cell tumour is a locally aggressive tumour arising from the synovia of the fibrous tissue surrounding the joints, tendon sheaths and tendons. Areas of predilection are the hand, and in the case of synovial joints, the knee joint is particularly affected. We describe a rare case of an intra-articular localized tenosynovial giant cell tumour arising from the anterior cruciate ligament (ACL) in a 27 year male who presented with pain and giving way of his left knee without prior history of any trauma. Tests for internal derangement of knee were negative. MRI reported an ACL tear with a heterogeneous fibrous mass attached to the distal part, most probably an organized haematoma. It was decided to do a diagnostic arthroscopy before proceeding for ACL reconstruction. Arthroscopy revealed a purple coloured mass attached to distal part of ACL. The mass was removed piecemeal using an additional posterolateral portal. ACL was found intact. Histopathology reported it to be tenosynovial giant cell tumour. The patient was asymptomatic at each subsequent follow up. It is a rare diagnosis which presented as an ACL tear; in such suspected cases it is prudent to perform a diagnostic arthroscopy before going for ACL reconstruction.

The purpose of this paper was to describe a rare unusual case of primary mandibular condylar tenosynovial giant cell tumor of diffuse type with predominantly intraosseous growth and its management by resection and functional reconstruction with a vascularized costochondral graft. Clinical presentation was swelling in the right condylar area and limited mouth opening with radiological evidence of central bone destruction and magnetic resonance imaging showed central hemosiderin deposition. Fine needle aspiration did not lead to a diagnosis and an open biopsy had to be performed. Management consisted of tumor resection and reconstruction with a free vascularized costochondral graft. Tenosynovial diffuse type giant cell tumor of the temporomandibular joint is very rare. Complete resection leads to a low recurrence rate and reconstruction with a costochondral free vascularized flap leads to an excellent functional outcome.

Synovial chondromatosis is a rare pathology in the foot and ankle region. We present a case of concomitant tenosynovial chondromatosis of the extensor digitorum longus tendon and synovial chondromatosis of the ankle, which was successfully treated by extensor digitorum tendon tendoscopy and ankle arthroscopy.
METHODS: Therapeutic, Level IV: Case study.