Chondroid Tenosynovial Giant Cell Tumor of Temporomandibular Joint

Intratendinous Calcified Chondroid Mesenchymal Neoplasm: A Case Report

Introduction

We present a case report concerning calcified chondroid mesenchymal neoplasms (CCMN), a novel category of tumors that exhibit chondroid formation and contain fibronectin 1-receptor tyrosine kinase fusions.

Case Report

Our report focuses on a 73-year-old female patient who presented with pain in her right hip and gluteal region. Initially, the condition was misdiagnosed as calcific tendinitis based on X-ray imaging. However, a subsequent magnetic resonance imaging (MRI) revealed a solid lobulated mass originating from the right hamstring tendon origin, exhibiting heterogeneously hypointense T1-weighted signal, heterogeneously isointense proton density fat-suppressed signal, and heterogeneous contrast-enhancement compared to skeletal muscle. Further, investigation through computed tomography (CT) demonstrated intratumoral calcifications accompanied by erosive changes in the adjacent right ischial tuberosity. Histologic examination of a CT-guided biopsy confirmed the presence of large calcium pyrophosphate crystal deposits, along with benign chondroid tissue, thus supporting the diagnosis of CCMN. Notably, there is considerable overlap in the imaging characteristics of CCMN and the more commonly encountered calcific tendinitis (calcium hydroxyapatite depositional disease). Contrast-enhanced MRI findings play a crucial role in distinguishing between these two conditions.

Conclusion

To the best of our knowledge, this is the first documented report describing the imaging features of CCMN across multiple modalities, including radiography, CT, and MRI.

Surgical Techniques and Functional Reconstruction for Complex Tenosynovial Giant Cell Tumor of Temporal Bone and Middle Skull Base

Objectives: Temporal tenosynovial giant cell tumors (TGCTs) are often large and have invaded the middle skull base. It is difficult to protect the important neurovascular structures around the tumor and perform functional reconstruction on the basis of complete tumor resection. This study aimed at analyzing the surgical techniques and functional reconstruction during the operation of complex TGCT of temporal bone and middle skull base. Methods: Five patients with pathologically confirmed TGCT of different complex types in the temporal bone and middle skull base were treated in our hospital from December 2020 to February 2023. We collected and retrospectively analyzed their medical records, including medical imaging, surgical procedures, and follow-up data. Results: The tumors invaded beyond the temporal bone and destroyed the middle skull base in all cases, involving the intracranial space and other important neurovascular structures. The internal carotid artery, infratemporal fossa, pterygopalatine fossa, and parapharyngeal space were also involved in 1 case. All the patients' tumors were completely removed, and the operations were performed mainly via modified infratemporal fossa approach, or combined with expanded middle cranial fossa approach. All cases with temporal and skull base destruction were repaired using the temporalis muscle flap with no occurrence of intracranial complications. The dura mater, condyle of temporomandibular joint, facial nerve, and internal carotid artery were fully preserved. Normal maxillofacial morphology was also preserved. The air conductive hearing of 2 patients was preserved. Conclusions: We found and summarized some surgical techniques that can help safeguard the important structures around massive TGCTs of temporal bone and middle skull base, and reconstruct the defects after tumor resection. The techniques are effective and feasible.

Pexidartinib (TURALIO™): The First FDA-Indicated Systemic Treatment for Tenosynovial Giant Cell Tumor

Tenosynovial giant cell tumor is a rare proliferative tumor that arises from the synovium, bursae, or tendon sheaths due to an overproduction of colony-stimulating factor 1. Historically, treatment options for patients with local or diffuse tenosynovial giant cell tumor have been limited to surgical interventions. However, for some patients, surgical resection could worsen functional limitations and/or morbidity. In August 2019, the FDA approved pexidartinib (TURALIO™, Daiichi Sankyo), the first systemic treatment option for adult patients with symptomatic tenosynovial giant cell tumor associated with severe morbidity or functional limitations that were not amenable to improvement with surgery. Pexidartinib is an oral tyrosine kinase inhibitor with selective inhibition of colony-stimulating factor 1 receptor and is the first systemic therapy to show significant improvement in overall response rates when compared with placebo. Clinicians using pexidartinib should monitor for liver-related adverse events, which may require treatment interruption, dose reduction, or treatment discontinuation. Pexidartinib provides a novel non-surgical treatment option for patients with tenosynovial giant cell tumor that may significantly improve patients’ overall response, range of motion, physical function, tumor volume, and stiffness.