Soft Tissue Special Issue: Giant Cell-Rich Lesions of the Head and Neck Region

Real-world drug utilization and treatment patterns in patients with tenosynovial giant cell tumors in the USA

Aim: Real-world treatment patterns in tenosynovial giant cell tumor (TGCT) patients remain unknown. Pexidartinib is the only US FDA-approved treatment for TGCT associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Objective: To characterize drug utilization and treatment patterns in TGCT patients. Methods: In a retrospective observational study using IQVIA's linked prescription and medical claims databases (2018-2021), TGCT patients were stratified by their earliest systemic therapy claim (pexidartinib [N = 82] or non-FDA-approved systemic therapy [N = 263]). Results: TGCT patients treated with pexidartinib versus non-FDA-approved systemic therapies were predominantly female (61 vs 50.6%) and their median age was 47 and 54 years, respectively. Pexidartinib-treated patients had the highest 12-month probability of remaining on treatment (54%); 34.1% of pexidartinib users had dose reduction after their first claim. Conclusion: This study provides new insights into the unmet need, utilization and treatment patterns of systemic therapies for the treatment of TGCT patients.

Pediatric Gnathic Bony and Mesenchymal Tumors

Evaluation of bone pathology within the head and neck region, particularly the gnathic bonesis is complex, demonstrating unique pathologic processes. In part, this variation is due to odontogenesis and the embryological cells that may be involved, which can contribute to disease development and histologic variability. As with any boney pathosis, the key is to have clinical correlation, particularly with radiographic imaging prior to establishing a definitive diagnosis. This review will cover those entities that have a predilection for the pediatric population, and while it is not all inclusive, it should serve as a foundation for the pathologist who is evaluating bony lesions involving the craniofacial skeleton.

Ectopic Intrathyroidal Parathyroid Adenoma Presenting With Osteoporotic Fractures in a Young Man: A Case Report

Primary hyperparathyroidism (PHPT) can be associated with osteoporosis (OP) and fractures. We present a case of a 49-year-old male referred to our osteoporosis outpatient clinic due to a right femur osteoporotic fracture. At the age of 38, a right plantar nodular lesion was excised, and its histology was compatible with a deep dermis nodule formed by mononuclear and giant osteoclast-like cells. He has reported osteoporotic fractures since age 39 and renal colic episodes since age 45. His father had lipomas and renal colic episodes, and his paternal grandmother had lipomas. The laboratory evaluation was compatible with PHPT. A cervical ultrasound showed a 10mm single solid nodule in the left thyroid lobe, strongly hypoechogenic, with microcalcifications. Its cytology showed parathyroid tissue without atypia. Parathyroid scintigraphy had no uptake. A dual-energy X-ray absorptiometry scan showed a femoral neck Z-score of -4.3. He started alendronate/cholecalciferol (70mg/5600IU) weekly. He was submitted to a left hemithyroidectomy. Its histology showed an intrathyroidal parathyroid adenoma. Ectopic parathyroid adenomas are rare, of which 0.7%-6% are intrathyroidal. The excised foot lesion could be a brown tumour. Furthermore, calcium metabolism evaluation at that time might have allowed a PHPT diagnosis and its morbidity prevention. Osteoporotic fractures in young men must alert to secondary OP.

Small biopsies in the head and neck: Bone and soft tissue

Bone and soft tissue lesions in the head and neck encompass not only a broad morphologic spectrum but also significant inherent clinicopathologic overlap. Epidemiology, radiology, and location - similar to the diagnostic assessment in other sites - are especially important considerations in the context of an established mesenchymal proliferation. Herein, the approach towards diagnosis is stratified by morphology (spindle, sarcomatoid, epithelioid, round cell), cellular lineage (fibroblastic, nerve sheath, rhabdomyogenic), and tumor grade (benign, low- to high-grade malignant) as the basis of further immunohistochemical or molecular investigation.

Case report: a giant cell-rich gnathic bone lesion in a child with pycnodysostosis

Pycnodysostosis is a skeletal dysplasia characterized by short stature, generalized osteosclerosis, acro-osteolysis, and recognizable facial features. Oral manifestations are commonly described and include a high-arched palate with dental crowding and malocclusion, hypoplastic enamel, and retained deciduous teeth with impacted permanent teeth, and there is an increased risk of developing osteomyelitis of the jaw. We report here the history of a 9-year-old male with the typical facial and skeletal phenotype of pycnodysostosis but novel oral features. He presented with bilateral progressive facial swelling, which caused functional impairment with chewing and contributed to his severe obstructive sleep apnea (OSA). The severity of his OSA required surgical intervention, and the lesions were resected. Extensive bone remodeling and replacement by fibrous tissue were noted on submucosal dissection, and bilateral subtotal maxillectomies were required. The histopathology of the biopsied lesion was consistent with a giant cell-rich lesion. Genetic testing identified a pathogenic homozygous variant in the CTSK gene, c.953G > A, p. (Cys318Tyr). The proband had a good postsurgical response with sustained improvement in his sleep OSA. We present here the history and clinical characteristics of a patient with typical features of pycnodysostosis and an unusual presentation and histopathology of gnathic bone lesions. This report adds to the body of literature on this rare condition and also highlights the finding of giant cell-rich lesions of the gnathic bones. Giant cell-rich lesions in pycnodysostosis have previously been reported in two cases in the literature. While there is not enough evidence to support a certain association with pycnodysostosis, it is prudent to consider regular oral dental reviews in affected individuals to identify pathology early and avoid such life-threatening complications.

Aneurysmal bone cyst: a review

Aneurysmal bone cyst (ABC) is a benign locally destructive bone neoplasm composed of multi-loculated blood-filled cystic spaces. The most common sites of involvement are the meta-diaphysis of the long bones and posterior elements of the vertebrae. Secondary, ABC-like changes can complicate a variety of other benign and malignant primary bone neoplasms, including giant cell tumor, fibrous dysplasia, and osteosarcoma. About two-third of primary ABCs have a rearrangement of the USP6 gene, which is not present in the ABC-like changes that occur secondary to other primary bone tumors (i.e., secondary ABC). Primary ABC of bone carries a variable but generally high rate of local recurrence. This paper provides an overview of the pathophysiology, clinical presentation, radiographic and pathologic findings, treatment, and prognosis of ABC.

Oral giant cell tumor or giant cell granuloma: How to know?

Introduction

The distinction between giant cell tumors and giant cell granulomas is challenging, as both entities have overlapping diagnostic criteria, especially in oral locations. The two entities have similar clinical and radiological presentations, but they differ in their prognoses.

Objective

The main objective of this study was to list the clinical, radiological, histological, and prognostic features of maxillomandibular giant cell tumors and giant cell granulomas cases n order to assess their value as a diagnostic referral factor that may allow the distinction between maxillo-mandibular giant cell granuloma and giant cell tumor.

Study design

Data of maxillomandibular giant cell granulomas and giant cell tumors were assessed through a scoping review and a pre-existing systematic review of literature. We have also realized a bicentric retrospective study.

Results

Various criteria facilitate the differential diagnosis like age, size, locularity and presence of necrosis zone but not the gender. The most discriminating factors was symptomatology (reported in 72% of GCTs while only 15% of GCGs) and the distribution pattern of giant cells in the stroma (homogeneously dispersed in 80% of GCTs versus grouped in clusters in 86.7% of GCGs). Recurrences were most described for giant cell tumors than giant cell granulomas. Malignant transformation and pulmonary metastasis were exclusively reported for giant cell tumors.

Conclusion

As clinical and radiological elements are not sufficient to distinguish between these two entities, immunohistochemistry and molecular genetics can be represent diagnostic biomarkers to distinguish giant cell granulomas and giant cell tumors in oral cavity. We have attempted to define the main criteria for the differentiation of giant cell tumor and giant cell granuloma and propose a decision tree for the management of single maxillomandibular giant cell lesions.

Spinal giant cell-rich osteosarcoma-diagnostic dilemma and treatment strategy: A case report

BACKGROUND

Giant cell-rich osteosarcoma (GCRO) is a rare histological variant of osteosarcoma. Spinal GCROs are extremely rare, with challenging diagnosis and management. Herein, we present a case of spinal GCRO at T2, which was not diagnosed in initial biopsy but after T2 corpectomy. We detailed the clinical course, management strategy, and outcome after a 4-year follow-up.

CASE SUMMARY

A 17-year-old female patient presented with back pain followed by ascending paresthesia. Spinal computed tomography (CT) and magnetic resonance imaging (MRI) revealed a collapsed T2 vertebra with an enhancing osteolytic mass. CT-guided biopsy showed inconclusive morphology. Pathology from T2 corpectomy revealed GCRO. The patient subsequently received neoadjuvant chemotherapy followed by salvage operation of T2 costotransversectomy with grossly-total resection adjuvant chemoradiation. Upon treatment completion, she had complete GCRO remission. The 4-year follow-up spinal MRI showed no tumor recurrence.

CONCLUSION

Spinal GCRO poses unique challenges in obtaining sufficient tissue diagnosis and complete surgical removal. However, long-term local control of spinal GCRO is possible following complete resection and adjuvant chemoradiation

Clinical and Radiologic Response of Central Giant Cell Granuloma to Denosumab: A 6-Year Prospective Observational Study

Central giant cell granuloma (CGCG) is a rare lesion of the jaw occurring in young adults and adolescents. Surgery, the traditional mainstay of therapy, is associated with significant morbidity. Denosumab, a humanised monoclonal antibody to RANKL, is effective in a related entity, giant cell tumour of bone (GCTB), but experience in the more indolent CGCG is limited. This prospective observational study of all denosumab-treated CGCG at a tertiary referral centre (2015-2021) aimed to evaluate the safety, efficacy and recurrence risk using denosumab in CGCG at lower-frequency dosing than used for GCTB. All received standardised, time-limited courses of denosumab 120 mg with stepwise increase in dosing interval based on response. They were followed for up to 75 months using a radiation-minimising protocol: 3-monthly clinical, biochemical and radiological assessment (orthopantomograms, cone beam CT). Eight patients, median age 20.5 years [IQR 6], received 13 initial doses [IQR 10] of denosumab 120 mg. Radiologic response was seen after 5.5 doses [IQR 4.5]: ossification in all and size reduction in three. Recurrence occurred in four of seven completing therapy, observed 12 months post-cessation [IQR 6.5]. Larger baseline size, aggressive subtype and fewer than 12 initial doses were more common in the recurrence group. There was no osteonecrosis of the jaw. Hypocalcaemia occurred in one receiving modified dosing. This study represents the largest, most diverse cohort of denosumab-treated CGCG with the longest follow-up in literature. It demonstrates the efficacy of lower-frequency, time-restricted course of denosumab but highlights the risk of recurrence. Long-term follow-up is critical.

The clinical challenges and dilemma in the management of uncommon maxillary sinus tumors - A report of two cases

Maxillary sinus is the common site for the nose and paranasal sinus tumors with diverse histopathological types and the treatment for each may differ. Making a histopathological diagnosis on occasion can be challenging. We had two patients presenting with upper alveolus growth in whom establishing the histopathological diagnosis was challenging. Through clinical evaluation, imaging (computed tomography and/or magnetic resonance imaging) and identification of key histopathological features helped in the management of these patients.

Unicystic ameloblastoma with stromal giant cells: A case series of a rare entity

Ameloblastoma is a locally aggressive, benign epithelial odontogenic neoplasm currently classified to include conventional, unicystic, and extraosseous/peripheral subtypes. Giant cells have been reported in various malignancies but rarely in odontogenic neoplasms. To date, only a single case of unicystic ameloblastoma with stromal giant cells has been reported in the literature. We report two new cases with histologic features compatible with unicystic ameloblastoma with stromal giant cells. CD68 immunohistochemical staining of the giant cells supported a histiocytic origin. Further research is needed to better understand the origin and nature of these giant cells.

Giant cell tumor in the thyroid area: a case report in the novel location and review of literature

Giant cell tumor of soft tissue (GCT-ST) is a rare benign tumor of low malignant potential. It is thought to be the soft tissue counterpart of giant cell tumors of the bone due to its pathological resemblances. GCT-ST is most commonly found in superficial soft tissue of thigh, trunk and upper extremities. The head and neck region is rarely affected. Here for the first time, we describe a case of GCT-ST in the thyroid region. A 70-year-old female patient presented with a painless swelling in her left neck for the previous three weeks. The condition was initially diagnosed as thyroid goiter and left lobectomy was arranged. Intraoperative findings showed an irregular mass invading the strap muscles and trachea. Complete tumor resection was difficult, and part of the tumor was left in the thyroid bed. Histopathology of the resected specimen showed a mixture of mononuclear round to oval cells and multinucleated osteoclast-like giant cells. The giant cells were CD 68 positive. The patient received a revision surgery 3 months after the first operation to achieve complete resection. There was no recurrence in the first 3-month follow-up. However, 6 months after the revision surgery, the tumor recurred on both sides of the neck. The patient suffered from dysphagia and breathlessness. As further surgery and radiation therapy were not considered, denosumab was used as a novel agent After three months of treatment, the patient showed symptom-relief and tumor-regression. The patient continued to have tumor-regression after 1 year of the denosumab treatment. GCT-ST is a benign tumor, although in this case, it was showing features of malignancy. A review of the literature was conducted to identify previous studies on GCT-ST in the head and neck. We present this case for its rare location and novel treatment with denosumab.

Computed tomography and magnetic resonance imaging characteristics of giant cell tumors in the temporomandibular joint complex

Purpose

This study aimed to investigate the computed tomography and magnetic resonance imaging features of giant cell tumors in the temporomandibular joint region to facilitate accurate diagnoses.

Materials and Methods

From October 2007 to June 2020, 6 patients (2 men and 4 women) at Yonsei University Dental Hospital had histopathologically proven giant cell tumors in the temporomandibular joint. Their computed tomography and magnetic resonance imaging findings were reviewed retrospectively, and the cases were classified into 3 types based on the tumor center and growth pattern observed on the radiologic findings.

Results

The age of the 6 patients ranged from 25 to 53 years. Trismus was found in 5 of the 6 cases. One case recurred. The mean size of the tumors, defined based on their greatest diameter, was 32 mm (range, 15–41 mm). The characteristic features of all cases were a heterogeneously-enhancing tumorous mass with a lobulated margin on computed tomographic images and internal multiplicity of signal intensity on T2-weighted magnetic resonance images. According to the site of origin, 3 tumors were bone-centered, 2 were soft tissue-centered, and 1 was peri-articular.

Conclusion

Computed tomography and magnetic resonance imaging yielded a tripartite classification of giant cell tumors of the temporomandibular joint according to their location on imaging. This study could help clinicians in the differential diagnosis of giant cell tumors and assist in proper treatment planning for tumorous diseases of the temporomandibular joint.

Central giant cell granuloma of the maxilla: Long-term follow-up of a patient treated with an adjuvant corticosteroid

BACKGROUND

Central giant cell granuloma (CGCG) is one of the most intriguing lesions of the jaws and its nature has not yet been fully elucidated. Clinically, some CGCG behave more aggressively, while others have an indolent course. In cases of aggressive CGCG of the maxilla, effective personalized therapies are worth understanding.

CASE REPORT

We report here a challenging case of aggressive CGCG in a 15-year-old girl which was misdiagnosed as an endodontic lesion. Radiographically, a large osteolytic lesion involving the hard palate from the central incisor to the second premolar, extending into the nasal cavity, with loss of the lamina dura and cortical resorption was observed. The lesion expanded aggressively after extensive curettage. With possible mutilation and defects due to a more radical approach to the lesion, treatment with systemic prednisone and intralesional triamcinolone hexacetonide associated with a calcitonin nasal spray was instituted. The decision in favor of this therapeutic strategy was made after careful immunohistochemical analysis of calcitonin and glucocorticoid receptors. The H-score for the staining of glucocorticoid and calcitonin receptors in multinucleated giant cells was 222 and 153.6, respectively. The lesion reduced in size, and no adverse effects associated with medications were observed. Another curettage was performed, and only fibrous connective tissue was found. The patient is in follow-up for 11 years without evidence of recurrence.

CONCLUSION

Pharmacological agents hold clinical promise in cases of aggressive CGCG affecting the maxilla of pediatric patients. Investigating the expression of calcitonin and glucocorticoid receptors in order to plan treatment is very helpful in the decision to manage aggressive CGCG.

A rare case of a metastatic giant cell-rich osteosarcoma of the mandible: Update and differential diagnostic considerations

A metastatic giant cell-rich osteosarcoma (GCRO) to the jaws is an exceedingly rare neoplasm. To date, fewer than 10 cases have been reported in the English language literature. In this article, we describe an additional case of a metastatic GCRO that presented the diagnostic challenge of a painless mass in the posterior mandible of a 19-year-old girl who exhibited rapid and aggressive local growth. The lesion was confirmed radiologically as an ill-defined expansive osteolytic mass showing cortical perforation. Microscopically, the presence of osteoclast-like giant cells permeated with atypical oval and rounded mesenchymal cells in a fibrovascular stroma, cellular atypia, and scarce osteoid formation were observed. Immunohistochemistry revealed the Ki-67 proliferative index in 50% of positive cells, positivity for vimentin and CD68, as well as scarce positivity for CDK4. The patient's medical history involved a GCRO in the proximal ulna. This report highlights the aggressive behavior of GCRO and its high capacity for metastasis to different parts of the body. Clinicians, pathologists, and surgeons should be aware of the giant cell-rich variant of osteosarcoma of the jaws, an imminent "wolf in a sheep's skin", because its indolent but unrelenting growth and dissemination, with radiographic and histologic characteristics that may represent a diagnostic pitfall regarding aggressive central giant cell lesions of the jaws.

Tenosynovial Giant Cell Tumor of the Retropharynx: A Case Report With Literature Review

Tenosynovial giant cell tumor (TSGCT) represents a family of benign tumors that arise from the synovial tissue of a joint, tendon sheath, or bursa. It usually involves the joints of the extremities and rarely occurs in the head and neck region. Here, we describe a case of a 32-year-old man with a submucosal mass bulging in the posterior pharyngeal wall since one month. The lesion was removed and diagnosed with localized type of TSGCT based on histopathological investigations and clinical presentation. It is very rare that TSGCT occurs in the retropharynx, which reminds clinicians to consider this entity as a possible diagnosis.