Cellular mechanisms of osteoclast formation and lacunar resorption in giant cell granuloma of the jaw

Efficacy and Toxicity of Calcitonin Treatment in Children with Cherubism: A Single-Center Cohort Study

Cherubism is a rare autosomal dominant disease characterized by expansile osteolytic jawbone lesions. The effect and safety of off-label calcitonin treatment during the progressive phase of the disease are not well described. In this retrospective study, we present data on the radiological response and adverse effects of subcutaneously administered calcitonin in a cohort of nine cherubism children (three female, six male). Two of the nine patients underwent two separate treatment courses with a significant off-treatment interval in between; therefore, a total of 11 treatment courses with a mean duration of 17.9 months (range <1 to 35, SD 10.8) were studied. To measure the response, the cumulative volume of cherubism lesions was calculated from available three-dimensional imaging. The primary outcome was the change in the volume of lesions during calcitonin treatment and only assessed for the eight treatment courses with a minimal duration of 6 months. A statistically significant reduction in the mean cumulative volume of lesions was seen regardless of treatment duration. Average volume reduction was highest in the first half year of treatment, with a gradual, ongoing reduction thereafter. For the secondary outcome, the change in the cumulative volume of lesions after treatment cessation was assessed for the seven treatment courses with follow-up imaging available. After six of these seven treatment courses, the cumulative volume increased again but remained undoubtedly smaller than the initial volume at the start of therapy. Adverse effects were assessed for all 11 treatment courses and occurred in 73% of them. Most adverse effects were mild and low grade, with the most severe being one grade 3 symptomatic hypocalcemia requiring hospitalization and early treatment termination. Calcitonin treatment seems effective and tolerable in treating actively progressing cherubism in children. However, further research is required to better understand the pharmacological treatment of cherubism, including also other drugs, dosing, and protocols. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Giant cell epulis

Giant cell epulis (peripheral giant cell granuloma) typically appears as a reactive benign lesion in the oral cavity in areas following local irritation or chronic trauma. Here we describe the case of a 45-year-old male patient who presented with the chief complaint of a large gingival mass in the anterolateral maxilla. There had been progressive growth within the past few months, with increased painless discomfort during mastication. The patient also reported bleeding during interdental cleaning. A full physical work-up led to the suspicion of giant cell epulis alongside other differentials including mucosal hemangioma and squamous cell carcinoma, with unremarkable laboratory values. Imaging including computed tomography showed signs of previous insertion of metal implants on either side of the lesion alongside mucosal hyperplasia. A confirmatory biopsy was taken and showed multiple giant cells on a reactive bed of stroma, in line with the diagnosis of giant cell epulis. Oral inflammatory conditions such as giant cell epulis have greater chances of local recurrence and, therefore, careful investigation with timely and accurate diagnosis is imperative for appropriate early treatment. Complete surgical excision should then be employed to prevent relapses, as incomplete removal can lead to further recurrence. Identification and eradication of potential sources of irritation should also be considered when treating the patient, to avoid further recurrence.

RANKL inhibition for giant cell lesions of the jaw: A retrospective cohort analysis

BACKGROUND

In all giant-cell-rich lesions (GCRL) occurring in bone, a common underlying excessive RANKL expression is held responsible for the osteolytic activity. Apart from giant cell tumour of bone (GCTB), systematic outcome analysis of RANKL inhibition in other GCRL is unavailable. The aim of this study is to assess the efficacy and safety of a 1-year denosumab protocol in giant cell lesions of the jaw (GCLJ).

METHODS

A retrospective cohort study was conducted compromising patients treated with a 1-year protocol of monthly subcutaneously administered 120 mg denosumab. Objective tumour response based on histology and imaging was used to calculate objective tumour response rate, progression-free survival (PFS) and time to progression. Type, severity and frequency of adverse events were recorded in a standardised way to assess safety.

RESULTS

Twenty patients, predominantly female (90%), were included. Fifty-five per cent of lesions were located in the mandible; most classified as aggressive lesions (90%). Thirty-five per cent (7/20) of cases were either recurrent after prior treatment or progressive, while on other drug treatment. Objective tumour response rate was 100% after 12 months of treatment. Median PFS was 50.4 months (95% CI 38.0-62.8) with a cumulative PFS rate of 22.6% (95% CI 1.8-43.4) at 5 years follow-up. Median time to progression was 38.4 months (95% CI 26.0-50.8). Treatment was well tolerated, and none of the patients had to interrupt therapy for toxicity.

CONCLUSION

High-dose denosumab is effective and safe in achieving a complete response in GCLJ within 12 months. The high long-term relapse rate after treatment cessation is the main obstacle for denosumab to become standard treatment for GCLJ.

Multiple versus solitary giant cell lesions of the jaw: Similar or distinct entities?

The majority of giant cell lesions of the jaw present as a solitary focus of disease in bones of the maxillofacial skeleton. Less frequently they occur as multifocal lesions. This raises the clinical dilemma if these should be considered distinct entities and therefore each need a specific therapeutic approach. Solitary giant cell lesions of the jaw present with a great diversity of symptoms. Recent molecular analysis revealed that these are associated with somatic gain-of-function mutations in KRAS, FGFR1 or TRPV4 in a large component of the mononuclear stromal cells which all act on the RAS/MAPK pathway. For multifocal lesions, a small group of neoplastic multifocal giant cell lesions of the jaw remain after ruling out hyperparathyroidism. Strikingly, most of these patients are diagnosed with jaw lesions before the age of 20 years, thus before the completion of dental and jaw development. These multifocal lesions are often accompanied by a diagnosis or strong clinical suspicion of a syndrome. Many of the frequently reported syndromes belong to the so-called RASopathies, with germline or mosaic mutations leading to downstream upregulation of the RAS/MAPK pathway. The other frequently reported syndrome is cherubism, with gain-of-function mutations in the SH3BP2 gene leading through assumed and unknown signaling to an autoinflammatory bone disorder with hyperactive osteoclasts and defective osteoblastogenesis. Based on this extensive literature review, a RAS/MAPK pathway activation is hypothesized in all giant cell lesions of the jaw. The different interaction between and contribution of deregulated signaling in individual cell lineages and crosstalk with other pathways among the different germline- and non-germline-based alterations causing giant cell lesions of the jaw can be explanatory for the characteristic clinical features. As such, this might also aid in the understanding of the age-dependent symptomatology of syndrome associated giant cell lesions of the jaw; hopefully guiding ideal timing when installing treatment strategies in the future.

Treatment of central giant cell granuloma in children with denosumab

Central giant cell granuloma (CGCG) is a benign but locally aggressive intraosseous lesion of the mandible. Historically, it is treated by curettage or resection. Medical therapy is indicated when surgery is associated with increased morbidity or in adjuvant setting to decrease recurrence. Treatment of CGCG with denosumab, a receptor activator of nuclear factor kappa-beta (RANK) ligand inhibitor, is not well studied, especially in children. Here, we describe our experience with the use of denosumab in the treatment of six children with CGCG. All patients had a favorable response with manageable side effects, which suggests that denosumab is an effective treatment option without increased morbidity.

Relative frequency of oral focal reactive overgrowths: An institutional retrospective study

Context:

Focal fibrous hyperplasia, peripheral ossifying fibroma, pyogenic granuloma, peripheral giant cell granuloma, giant cell fibroma and focal reactive overgrowth (FROGs) are one of the foremost numerous benign soft-tissue growths in the oral cavity. Chronic irritation or trauma is with identified as the causative aspect. It may develop up to few centimeters in diameter, pedunculated or sessile and may arise on the gingiva or buccal mucosa. Treatment involves surgical excision, and recurrences are infrequent.

Aims:

The aim of this study was to assess the prevalence of FROGs of oral mucosa in an institutional setup.

Subjects and Methods:

All the histopathologically diagnosed cases of FROGs within a period of 10 years (January 2008–December 2017) were retrieved from the archives of the Department of Oral Pathology. The information such as age, sex, site, anatomical side and its prevalence were recorded on customized case history performa.

Statistical Analysis Used:

The significance of difference was assessed using the Chi-square test and Fisher's exact test.

Results:

A total of 2849 cases were identified, of which 449 (15%) were FROGs. The most prevalent lesion amid them were focal fibrous hyperplasia (277, 62%), followed by pyogenic granuloma (92, 20%), whereas the least common was giant cell fibroma with 2 (0.5%) cases. All the FROGs were distributed among 21–40 years of age showing female predominance. The commonly affected site was the right buccal mucosa.

Conclusions:

Nevertheless, information of the frequency and distribution of these lesions is favorable when establishing a diagnosis and treatment plan in clinical practice.

Making sense of giant cell lesions of the jaws (GCLJ): lessons learned from next-generation sequencing

Next-generation sequencing has revealed mutations in several bone-related lesions and was recently used to uncover the genetic basis of giant cell lesions of the jaws (GCLJ). Consistent with their benign nature, GCLJ show a low tumor mutation burden. They also harbor somatic, heterozygous, mutually exclusive mutations in TRPV4, KRAS, or FGFR1. These signature mutations occur only in a subset of lesional cells, suggesting the existence of a 'landscaping effect', with mutant cells inducing abnormal accumulation of non-mutant cells that form the tumor mass. Osteoclast-rich lesions with histological similarities to GCLJ can occur in the jaws sporadically or in association with genetically inherited syndromes. Based on recent results, the pathogenesis of a subgroup of sporadic GCLJ seems closely related to non-ossifying fibroma of long bones, with both lesions sharing MAPK pathway-activating mutations. In this review, we extrapolate from these recent findings to contextualize GCLJ genetics and we highlight the therapeutic implications of this new information. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Adjunctive Strategies for Benign Maxillofacial Pathology

Benign cysts and neoplasms of the maxillofacial region can vary in behavior, with some growing rapidly and resulting in destruction of surrounding structures. Despite their benign histology, many require often-morbid treatment to prevent recurrence of these lesions. Several less invasive and adjunctive medical treatments have been developed to lessen the morbidity of surgical treatment. As the molecular and genomic pathogenesis of these lesions is better understood, more directed treatments may lessen the burden for patients.

Immunoexpression of calcitonin and glucocorticoid receptors in central giant cell lesions of the jaws

BACKGROUND

This study analyzed the immunoexpression of calcitonin receptor (CTR) and glucocorticoid receptor (GR) in central giant cell lesions (CGCLs) and verified potential associations with patient's response to clinical treatment with intralesional injection of triamcinolone.

MATERIALS AND METHODS

Fifty-four cases of CGCLs, including 22 non-aggressive, and 32 aggressive, were investigated by immunohistochemistry.

RESULTS

Surgery was the therapeutic choice for 53.1% of the aggressive CGCLs, and 46.9% were submitted to the conservative treatment with intralesional triamcinolone injections. Among patients submitted to conservative treatment, 60% (n = 9) showed favorable response. CTR expression was observed in 68.51%, and GR in 94.44% of the total sample. There were no differences in the expression of CTR, neither GR in mononucleated stromal cells (MSCs) or multinucleated giant cells (MGCs), in relation to aggressiveness, treatment performed for and the response to conservative treatment. Both markers showed a positive correlation between their expression in MSCs and MGCs in the total sample (P < 0.0001). CTR expression on MSCs showed a positive correlation with MGCs in the aggressive and non-aggressive groups (P < 0.0001).

CONCLUSIONS

Calcitonin receptor and GR expression were diffuse and similar in non-aggressive and aggressive cases, and it did not influence the response to clinical treatment with triamcinolone in the sample studied.

Reactive lesions of oral cavity: A retrospective study of 659 cases

OBJECTIVE

This study reviews, analyzes, and compares the demographic data, histopathological features and discusses the treatment and prognosis of reactive lesions (RLs).

MATERIALS AND METHODS

Retrospective study was performed on the departmental archives from July 2006 to July 2016 (total 5000 cases) comprising of 659 cases of RLs of the oral cavity. The recorded data included age, gender, size, site, duration, habits, etiology, histopathological diagnosis, treatment, and prognosis.

RESULTS

The most common lesion was found to be inflammatory fibrous hyperplasia (47%) followed by pyogenic granuloma (PG) (27.16%) and the least cases were of peripheral giant cell granuloma (1.6%). The mean age for the occurrence was 4th-5th decade in all the RL's exceptperipheral ossifying fibroma (POF) which presented in the third decade. Female predominance was noted in all lesions except irritational FIB. The sizes of majority of the lesions were approximately 0.5-1 cm. The common sites were anterior maxilla followed by posterior mandible and least in tongue with no associated habits (82.2%). The duration of all the lesions was seen to be <1 year. Majority of them presented with poor oral hygiene status (87.2%). Recurrences were present in 13.5% of surgically excised lesions.

CONCLUSION

The RLs present commonly in oral cavity secondary to injury and local factors which can mimic benign to rarely malignant lesions. The clinical and histopathological examination helps to categorize the type of lesions. The complete removal of local irritants with follow-up and maintenance of oral hygiene helps to prevent the recurrences of such lesions.

IL-4 induces the formation of multinucleated giant cells and expression of β5 integrin in central giant cell lesion

Background

It is now well established that IL-4 has a central role in the development of monocytes to multinucleated giant cells (MGCs) by inducing the expression of integrins on the surface of monocytes. The aim of this study was to investigate the potential role of IL-4 in induction of β5 integrin expression in the peripheral blood samples of patients with giant cell granuloma.

Material and Methods

Monocytes were isolated from peripheral blood samples of patients with central giant cell granuloma (CGCG) and healthy controls using human Monocyte Isolation Kit II. Isolated monocytes were then cultured in the absence or presence of IL-4 (10 and 20 ng/mL), and following RNA extraction and cDNA synthesis, Real-time PCR was performed to determine the level of β5 integrin expression. The formation of CGCGs and morphological analyses were done under light microscopy. For confirmation of CGCGs, immunocytochemistry technique was also carried out by anti-RANK (receptor-activator of NF-κB ligand) antibody.

Results

In both patient and control groups, β5 levels were significantly enhanced by increasing the IL-4 dose from 10 to 20 ng/mL. In addition, these differences were significant between patient and control groups without IL-4 treatment. On the other hand, the number of cells which expressed RANK and therefore the number of giant cells were significantly higher in the patient group in comparison to controls, as assessed by immunohistochemistry evaluations.

Conclusions

In this study, we showed an elevation in the expression levels of β5 integrin when stimulated by IL-4. It is strongly indicated that this integrin acts as an important mediator during macrophage to macrophage fusion and development of giant cells.

Key words:β5 integrin, giant cell, Il-4, monocyte, rank.

Pharmacological and surgical therapy for the central giant cell granuloma: A long-term retrospective cohort study

PURPOSE

This is a retrospective cohort study of patients with a central giant cell granuloma (CGCG) treated at a single center to assess and compare the different surgical and non-surgical approaches.

MATERIAL AND METHODS

A cohort with a single histologically proven non-syndrome-related CGCG was selected and reviewed. Patients were allocated to group I (surgery), group II (pharmacotherapy), and group III (pharmacotherapy and surgery). The primary outcome was long-term radiologic response using computed tomography. Secondary outcomes were intermediate radiologic responses and occurrence and severity of side effects.

RESULTS

Thirty-three subjects were included in the study. The surgical group (n = 4) included 1 patient with progression during follow-up and a relatively high post-surgical morbidity. Twenty-nine patients started on various pharmacological treatment regimens (groups II and III). Fourteen patients could be managed without additional surgery. One of these lesions showed progression during follow-up. The other 15 lesions underwent additional surgery, and none showed progression during follow-up. Interferon treatment was associated with the most side effects.

CONCLUSION

Pharmacological agents have a role in the treatment of aggressive and non-aggressive CGCGs by limiting the renewed progression during long-term follow up and the extent and morbidity of surgical treatment.

Genetic Analysis of Giant Cell Lesions of the Maxillofacial and Axial/Appendicular Skeletons

PURPOSE

To compare the genetic and protein expression of giant cell lesions (GCLs) of the maxillofacial (MF) and axial/appendicular (AA) skeletons. We hypothesized that when grouped according to biologic behavior and not simply by location, MF and AA GCLs would exhibit common genetic characteristics.

MATERIALS AND METHODS

This was a prospective and retrospective study of patients with GCLs treated at Massachusetts General Hospital from 1993 to 2008. In a preliminary prospective study, fresh tissue from 6 aggressive tumors each from the MF and AA skeletons (n = 12 tumors) was obtained. RNA was extracted and amplified from giant cells (GCs) and stromal cells first separated by laser capture microdissection. Genes highly expressed by GCs and stroma at both locations were determined using an Affymetrix GeneChip analysis. As confirmation, a tissue microarray (TMA) was created retrospectively from representative tissue of preserved pathologic specimens to assess the protein expression of the commonly expressed genes found in the prospective study. Quantification of immunohistochemical staining of MF and AA lesions was performed using Aperio image analysis to determine whether immunoreactivity was predictive of aggressive or nonaggressive behavior.

RESULTS

Five highly ranked genes were found commonly in GCs and stroma at each location: matrix metalloproteinase-9 (MMP-9), cathepsin K (CTSK), T-cell immune regulator-1 (TCIRG1), C-type lectin domain family-11, and zinc finger protein-836. MF (n = 40; 32 aggressive) and AA (n = 48; 28 aggressive) paraffin-embedded tumors were included in the TMA. The proteins CTSK, MMP-9, and TCIRG1 were confirmed to have abundant expression within both MF and AA lesions. Only the staining levels for TCIRG1 within the GCs predicted the clinical behavior of the MF lesions.

CONCLUSIONS

MMP-9, CTSK, and TCIRG1 are commonly expressed by GCLs of the MF and AA skeletons. This supports the hypothesis that these lesions are similar but at different locations. TCIRG1 has not been previously associated with GCLs and could be a potential target for molecular diagnosis and/or therapy.

A Clinicopathological Study of 52 Feline Epulides

A retrospective study was performed to characterize 52 new cases of feline epulides between 1995 and 2001, with clinical and pathological results classified according to Head's histopathologic criteria for canine epulides. The incidence of the fibromatous, acanthomatous, ossifying, and giant cell epulis were respectively 57.7% (30/52), 7.7% (4/52), 5.8% (3/52), and 28.8% (15/52). Giant cell epulides presented significant differences in clinical behavior compared with the fibromatous type, including rapid growth ( P < .0001), presence of ulcerative changes ( P < .01), and rapid recurrence after surgery ( P < .01) from which euthanasia was judged necessary in 4 cases. Fifteen giant cell epulides were additionally examined in order to characterize the lesion both histochemically and immunohistochemically and to investigate the origin of the multinucleated giant cells (MGCs). Van Gieson staining showed osteoid and woven bone formation in 11 cases. Both the MGCs and a fraction of the mononuclear cells were positive for vimentin, tartrate-resistant acid phosphatase (TRAP), a commonly accepted marker for osteoclasts, and the polyclonal antibody receptor activator of nuclear factor κβ (RANK), a cytokine leading to the differentiation of osteoclast progenitors into mature osteoclasts in presence of its ligand. MGCs were negative for smooth muscle actin, MIB-1, and factor VIII. The giant cell epulis may be a variant of the fibromatous and ossifying epulis in which extensive ulceration and inflammation results in increased osteoclastic activity. The osteoclast-like giant cells are most likely formed from a monocyte/ macrophage-like osteoclast precursor that differentiates into osteoclasts under the influence of mononuclear osteoblast-like stromal cells.

Pediatric Vascular Tumors of the Head and Neck

Oral and maxillofacial surgeons are often involved in the diagnosis and treatment of vascular neoplasms of the head and neck. An incorrect diagnosis may lead to improper or unnecessary treatment. This article reviews the diagnosis and management of vascular tumors.

Expression of CD34 and CD68 in peripheral giant cell granuloma and central giant cell granuloma: An immunohistochemical analysis

Background:

Central and Peripheral giant cell granulomas of jaws are uncommon, benign, reactive disorders that are characterized by the presence of numerous multinucleated giant cells and mononuclear cells within a stroma. The origin of the multinucleated giant cells is controversial; probably originating from fusion of histiocytes, endothelial cells and fibroblasts.

Objective:

To assess the expression of CD34 and CD68 in central and peripheral giant cell granulomas to understand the origin of these multinucleated giant cells.

Materials and Methods:

Twenty cases of Central and Peripheral giant cell granulomas were evaluated immunohistochemically for CD34 and CD68 proteins expression.

Results:

Immunopositivity for CD34 was seen only in cytoplasm of endothelial cells of blood vessels; whereas, consistent cytoplasmic immunopositivity for CD68 was seen in few stromal cells. Statistical significance was seen in mean number of multinucleated giant cells, mean number of nuclei in multinucleated giant cells, CD68 expression and ratio of macrophages to multinucleated giant cells among two lesions.

Conclusion:

Although the central giant cell granulomas share some clinical and histopathological similarities with peripheral giant cell granulomas, differences in mean number of nuclei in multinucleated giant cells and CD68 immunoreactivity may underlie the distinct clinical behavior.

Central giant cell granuloma of posterior maxilla: first expression of primary hyperparathyroidism

A case of 19-year-old male patient reported with the chief complaint of slowly growing diffuse painless swelling over the right part of the face from last 6 months. Intraoral examination revealed a swelling on right side of palate in relation to molar region with buccal cortical plate expansion. Radiographic examination (orthopantograph and 3DCT) showed large multilocular radiolucency in right maxilla with generalized loss of lamina dura. Incisional biopsy was done and specimen was sent for histopathological examination which showed multinucleated giant cells containing 15-30 nuclei. Based on clinical, radiological, and histopathological findings provisional diagnosis of central giant cell granuloma was made. Blood tests after histopathology demonstrated elevated serum calcium level and alkaline phosphatase level. Immunoassay of parathyroid hormone (PTH) level was found to be highly elevated. Radiographic examination of long bones like humerus and femur, mandible, and skull was also done which showed osteoclastic lesions. Considering the clinical, radiographic, histopathological, and blood investigation findings, final diagnosis of brown tumour of maxilla was made. The patient underwent partial parathyroidectomy under general anaesthesia to control primary hyperparathyroidism. Surgical removal of the bony lesion was done by curettage. The patient has been followed up for 1 year with no postoperative complications and the lesion healed uneventfully.

Immunohistochemical comparison of p53, Ki-67, CD68, vimentin, α-smooth muscle actin and alpha-1-antichymotry-psin in oral peripheral and central giant cell granuloma

INTRODUCTION

Giant cell lesions are characterised histologically by multinucleated giant cells in a background of ovoid to spindle-shaped mesenchymal cells. There is a major debate whether these lesions are separate entities or variants of the same disease. Our aim was to study the nature of multinucleated and mononuclear cells from peripheral giant cell granuloma (PGCG), and central giant cell granuloma (CGCG) and giant cell tumor (GCT) of long bones using immunohistochemistry evaluation and to determine whether there is a correlation between recurrence and the markers used.

MATERIALS AND METHODS

Ki-67, p53, Vimentin, smooth muscle specific actin, CD68 and alpha-1-antichymotrypsin were used to study 60 giant cell lesions. These included 26 CGCG, 28 PGCG, and 6 GCT cases using an avidin-biotin-complex immunohistochemistry standard method.

RESULTS

All studied cases showed the same results except the percentage of Ki-67 positive mononuclear cells in PGCG was significantly higher than that of both CGCG and GCT (p<0.05). Interestingly, no statistical correlation between recurrence and the markers used was found.

CONCLUSION

Our results may suggest that these lesions have the same histogenesis. The mononuclear stromal cells, both histiocytic and myofibroblastic, are thought to be responsible for the behavior of these lesions whereas the multinucleated cells are considered as reactive. This might support the argument that PGCG, CGCG and GCT are different variants for the same disease. Further studies using molecular techniques are required to elucidate why some of these lesions behave aggressively than others.

Recurrent case of central giant cell granuloma with multiple soft tissue involvement

Central giant cell granuloma is a fairly common lesion in the jaws aetiology of which is still completely unknown but thought to be of a reactive process to some unknown stimuli. It usually arises either peripherally in periodontal ligament, mucoperiosteum, or centrally in the bone. The histological hallmark for both peripheral and central giant cell granuloma (CGCG) is the presence of distinctive multinucleated giant cells (MGCs) in a prominent fibrous stroma. Central giant cell granuloma is an uncommon benign proliferative lesion that almost exclusively occurs within the jaw. Eventually, it may become aggressive leading to the expansion and perforation of cortex resulting into mobility and displacement of teeth with root resorption. The present case focuses on the dilemma and perplexity in diagnosing aggressive CGCGs, due to its close proximity with respect to pathology, behavior and prognosis from giant cell tumors (GCT). Central giant cell granuloma persuaded extensive destruction to the hard and soft tissues with high rate of recurrence encourage us the need of exploring the possibilities of giant cell tumors having a definitive presence in the jaws.

Fibrous dysplasia and central giant cell granuloma: a report of hybrid lesion with its review and hypotheticated pathogenesis

Benign fibro-osseous lesions (BFOLS) of the jaws are a wide array of lesions that actually represent distinct phases of a single benign morphological process. These lesions share certain histopathological features which are in common with giant cell containing lesions, which include central giant cell granulomas (CGCGs). The association of BFOLS and CGCG has to be critically evaluated, pertaining to their clinical, radiologic and histologic features. Many pathologists diagnose these types of lesions, considering only one of the prominent features. Eventually, surgeons end up treating these lesions inadequately. This ambiguity may be because of very small number of cases have been reported in the literature, with uncertain clinical, radiologic and histologic features. We are reporting a case of fibrous dysplasia (FD) which was associated with a central giant cell granuloma (CGCG) and discussing the hypothetical pathogenesis of giant cells.

RANKL, denosumab, and giant cell tumor of bone

PURPOSE OF REVIEW

Giant cell tumor (GCT) of bone is a benign, osteolytic neoplasm of bone. The receptor activator of NF-KB ligand (RANKL) pathway has recently been shown to play a key role in the pathogenesis of GCT.

RECENT FINDINGS

Treatment for refractory, recurrent, or metastatic GCT remains challenging. The recent development of a monoclonal antibody to RANKL, denosumab, offers promise in the management of these patients. A recent phase 2 study suggested denosumab offers disease and symptom control for patients with advanced or refractory disease. In this population, denosumab appears to be well tolerated. There are key questions which remain to be addressed, including patient selection, optimal scheduling, use as an adjuvant, and application to other giant cell-rich disorders.

SUMMARY

Denosumab offers a new treatment option for a subset of patients with previously untreatable GCT. The role of denosumab in curative treatment is the subject of ongoing studies.

CD14- mononuclear stromal cells support (CD14+) monocyte-osteoclast differentiation in aneurysmal bone cyst

Aneurysmal bone cyst (ABC) is a benign osteolytic bone lesion in which there are blood-filled spaces separated by fibrous septa containing giant cells. The nature of the giant cells in this lesion and the mechanism of bone destruction in ABC is not certain. In this study, we have analysed several characteristics of mononuclear and multinucleated cells in the ABC and examined the cellular and molecular mechanisms of ABC osteolysis. The antigenic and functional phenotype of giant cells in ABC was determined by histochemistry/immunohistochemistry using antibodies to macrophage and osteoclast markers. Giant cells and CD14+ and CD14- mononuclear cells were isolated from ABC specimens and cultured on dentine slices and coverslips with receptor activator of nuclear factor κB ligand (RANKL)+/- macrophage-colony stimulating factor (M-CSF) and functional and cytochemical evidence of osteoclast differentiation sought. Giant cells in ABC expressed an osteoclast-like phenotype (CD51+, CD14-, cathepsin K+, TRAP+) and were capable of lacunar resorption, which was inhibited by zoledronate, calcitonin and osteoprotegerin (OPG). When cultured with RANKL±M-CSF, CD14+, but not CD14-, mononuclear cells differentiated into TRAP+ multinucleated cells that were capable of lacunar resorption. M-CSF was not necessary for osteoclast formation from CD14+ cell cultures. CD14- cells variably expressed RANKL, OPG and M-CSF but supported osteoclast differentiation. Our findings show that the giant cells in ABC express an osteoclast-like phenotype and are formed from CD14+ macrophage precursors. CD14- mononuclear stromal cells express osteoclastogenic factors and most likely interact with CD14+ cells to form osteoclast-like giant cells by a RANKL-dependent mechanism.

Increased TNF-α, IL-6 and decreased IL-1β immunohistochemical expression by the stromal spindle-shaped cells in the central giant cell granuloma of the jaws

Objectives: the exp ress ion of the osteoclastogenic cytokines TNF-α, IL-6 and IL-1β were immunohistochemically evaluated in periph eral (PGCG) and central (CGCG) giant cell granulomas of the jaws in order to determine diff erences between these two lesions and between the two distinct tumor cell populations (multinucleated giant cells, MGCs and stromal sp indle-sh aped cells). Study Design: Paraffin-embedd ed tiss ue sections from 40 PGCG and 40 CGCG were immunohistochemically stained using antibodies against TNF-α, IL-6 and IL-1β. The percentage of positively stained cells and the staining intensity were ass ess ed to provide a combined immunoreactivity score value. Results: TNF-α, IL-6 and IL-1β were exp ress ed in all lesions. The CGCG compared to the PGCG sh owed significantly increased exp ress ion of TNF-α and IL-6 and decreased exp ress ion of IL-1β by the sp indle-sh aped cells and increased exp ress ion of IL-1β by the MGCs. The MGCs demonstrated in comparison to the stromal sp indlesh aped cells significantly increased exp ress ion of all three cytokines in both PGCG and CGCG. Conclusions: The proinflammatory cytokines TNF-α, IL-6 and IL-1β seem to be involved in the growth process of PGCG and CGCG of the jaws. A poss ible alteration in the sy nthesis or/and activity of these cytokines by the stromal sp indle cells in the CGCGs may enhance osteolys is through the stimulation of osteoclast progenitor cells, given the fact that the intraoss eous lesions cause bone resorption.

Key words: Giant cell granuloma, giant cell tumor, multinucleated giant cells, jaw, TNF-alpha, IL-6, IL-1beta, immunohistochemistry.

Cyclooxygenase-2 expression in central giant cell lesion of the jaws: an immunohistochemical study

Central Giant Cell Lesion (CGCL) is an uncommon benign jaw lesion, with uncertain etiology, and a variable clinical behavior. Studies of molecular markers of CGCL, may help understanding better the nature and behavior of this lesion, and eventually may represent a definitive target to pharmacological approach in the treatment of CGCL. Chronic inflammation has been found to mediate a wide variety of diseases including neoplasms. Among the gene products involved in the induction of the inflammatory process, Cyclooxygenase 2 (COX-2) has been shown to have a close relationship with tumorigenesis, however COX-2 expression has never been evaluated in CGCL. The aim of the study was to investigate the expression of COX-2 in CGCL. Immunohistochemical assessment for COX-2 expression was performed in 18 patients previously diagnosed with CGCL. Multinucleated giant cells (MGC) and mononucleated stromal cells (MSC) were used in the slide analysis. Among the patients studied, 10 were male and 8 were female, with a median age of 15.4 years. Lesions in the mandible were observed in 11 cases and 7 were found in the maxilla. There were 9 aggressive and 9 non-aggressive CGCLs. COX-2 immunopositivity was present in only 3 cases stained in both MGC and MSC. All 3 cases presented with ulcerations in the mucosa lesion, suggesting that the COX-2 expression is due to the presence of inflammation. This study does not support the involvement of COX-2 in the etiophatogenesis of CGCL.

Calcitonin use in giant cell bone tumors

INTRODUCTION

As osteoclast, giant cell tumors express calcitonin receptors. The aim of this paper is to assess treatment using salmon calcitonin after curettage.

MATERIAL AND METHODS

We retrospectively reviewed 25 patients with giant cell tumor of the appendicular skeleton treated with a single protocol of calcitonin administration following curettage in order to assess the effectiveness of calcitonin in reducing the rate of local recurrence.

RESULTS

The mean duration follow-up was 68 months. Thirteen patients (52%) had local recurrence. Eight of them were treated successfully after repeated curettage and calcitonin. Four patients had bone resection and one patient had curettage and cement filling. All patients with cavity left empty had ossified and the functional score as assessed by the MSTS score was 28.02/30.

CONCLUSION

This study suggests that the use of calcitonin as adjuvant is not effective and that filling agents are not required after curettage of giant cell tumors.

LEVEL OF EVIDENCE

Level 4.

Orthopedic and Orthodontic Treatment in Central Giant Cell Granuloma Treated with Calcitonin

Central giant cell granuloma of the jaw is a benign lesion of unknown etiology that occurs with very low frequency. It mainly occurs in children and young adults and is more common in the mandible. The most common treatment is surgical removal; however, alternative therapies (intralesional injections of corticosteroids, interferon alpha, and calcitonin) have been used in order to avoid undesirable damage to the jaws and teeth. The lesion may cause root resorption, tooth germ displacement, and other dental problems, as well as malocclusion that must be treated orthodontically. The orthodontic, orthopedic, and calcitonin-based treatments of one of these cases is presented.

Combined treatment of aggressive central giant cell granuloma in the lower jaw

BACKGROUND

The aggressive type lesions of central giant cell granuloma (CGCG) require wide resection that leads to major defects in the jaws. This form of surgical treatment can be particularly disfiguring. A number of alternative non-surgical therapies have been advocated in recent years for the management of the central giant cell granuloma (CGCG). These include calcitonin injections and nasal spray, intralesional steroid injections and subcutaneous interferon injections.

MATERIALS AND METHODS

A large central giant cell granuloma aggressive type lesion in the mandible of a 24-year-old patient was treated successfully by intralesional injection of corticosteroid and nasal spray calcitonin that was followed by curettage with peripheral ostectomy with preservation of the continuity of the mandible and the teeth. At the 5-year clinical and radiological follow up there was no sign of recurrence.

CONCLUSIONS

This combined medical and surgical treatment is advantageous for large aggressive lesions in order to reduce the size of the lesion and thus minimize the need for extensive bone resection and loss of teeth that can result in functional and aesthetic defects.

Increased expression of NFATc1 in giant cell lesions of the jaws, cherubism and brown tumor of hyperparathyroidism

A variety of diseases of the jaws may present multinucleated giant cells. These diseases include central giant cell lesions (CGCL), peripheral giant cell lesions (PGCL), brown tumor of hyperparathyroidism (BTH), and cherubism. The multinucleated giant cells in these lesions are osteoclast-like. Since NFATc1 plays a significant role in osteoclast differentiation, the present study aimed to compare the expression of NFATc1 in CGCL, PGCL, BTH and cherubism. A total of 14 formalin-fixed and paraffin-embedded tissue samples of CGCL (n=4), PGCL (n=5), BTH (n=3) and cherubism (n=2) were included in the study. An immunohistochemical analysis was performed to investigate the NFATc1 protein. The majority of giant cells in all of the cases were positive for nuclear NFATc1 and the immunostaining pattern was similar in all of the groups. Although our study supports the hypothesis that giant cell accumulation in PGCL, CGCL, BTH and cherubism is mediated by NFATc1, functional studies are required to investigate this hypothesis.