Giant cell tumor in skeletally immature patients

Bifunctional bone substitute materials for bone defect treatment after bone tumor resection

Aggressive benign, malignant and metastatic bone tumors can greatly decrease the quality of patients' lives and even lead to substantial mortality. Several clinical therapeutic strategies have been developed to treat bone tumors, including preoperative chemotherapy, surgical resection of the tumor tissue, and subsequent systemic chemo- or radiotherapy. However, those strategies are associated with inevitable drawbacks, such as severe side effects, substantial local tumor recurrence, and difficult-to-treat bone defects after tumor resection. To overcome these shortcomings and achieve satisfactory clinical outcomes, advanced bifunctional biomaterials which simultaneously promote bone regeneration and combat bone tumor growth are increasingly advocated. These bifunctional bone substitute materials fill bone defects following bone tumor resection and subsequently exert local anticancer effects. Here we describe various types of the most prevalent bone tumors and provide an overview of common treatment options. Subsequently, we review current progress regarding the development of bifunctional bone substitute materials combining osteogenic and anticancer efficacy. To this end, we categorize these biomaterials based on their anticancer mechanism deriving from i) intrinsic biomaterial properties, ii) local drug release of anticancer agents, and iii) oxidative stress-inducing and iv) hyperthermia-inducing biomaterials. Consequently, this review offers researchers, surgeons and oncologists an up-to-date overview of our current knowledge on bone tumors, their treatment options, and design of advanced bifunctional biomaterials with strong potential for clinical application in oncological orthopedics.

[Giant-cell tumor of bone in 2022]

Giant cell tumors of bone (GCTs) are rare mesenchymal tumors classified as intermediate in the WHO 2020 classification, i.e. neither completely benign nor definitely malignant, due to recurrence (frequent) and pulmonary metastases (rare). They involve the end of long bones as well as the axial bones of mature skeletons. They are made of mononuclear stromal tumor cells of (pre-) osteoblastic phenotype, mononuclear cells of the monocyte-macrophage lineage and osteoclast-like multinuclear giant cells responsible for tumor osteolysis. In 95% of cases, the stromal cells have a specific mutation in the H3F3A gene which encodes histone H3.3. The mutated H3.3 G34W protein (90% of cases) can be easily detected by immunohistochemistry, even on small samples. Many tumors or bone pseudotumors contain osteoclast-like giant cells, cells of the bone microenvironment, and should not be confused with GCT: mainly brown tumor of hyperparathyroidism, aneurysmal bone cyst, chondroblastoma, non-ossifying fibroma and central giant cell granuloma.

Update on aneurysmal bone cyst: pathophysiology, histology, imaging and treatment

Aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare. ABC can involve any bone in the body, and although it has a metaphyseal preference, it can involve any part of a bone and soft tissues. As with any bone tumor, the initial evaluation of ABCs should be done with radiographs followed by magnetic resonance imaging or less frequently computed tomography for further characterization. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. The main differential diagnosis of an ABC in the pediatric population is unicameral bone cyst (UBC) and telangiectatic osteosarcoma, therefore a biopsy is recommended before treatment. The therapeutic options of ABC range from curettage with or without adjuncts such as phenol, liquid nitrogen, argon laser and bone grafting or bone substitutes to more recently employed alternatives such as image-guided sclerotherapy with various sclerosing agents and monoclonal antibodies (e.g., Denosumab).

Characteristics of Giant Cell Tumor of the Bone in Pediatric Patients: Our 18-Year, Single-Center Experience

A giant cell tumor (GCT) of the bone is characteristically found in skeletally mature patients. The tumor is rare in pediatric patients, and incidence reported in literature varies from 1.8% to 10.6%. We performed a retrospective study addressing symptoms, treatment, and outcome in pediatric patients who were diagnosed with GCT between March 1997 and January 2015 at our hospital. Fourteen (11.1%) of 126 surgically treated patients with histologically proven GCT were <19 years of age. We confirmed skeletal maturity using magnetic resonance imaging (MRI). Fourteen patients from 8 to 19 years old were identified. Sixteen lesions (76.2%) were found in long bones and 5 lesions (23.8%) in short bones. The most common site was around the knee in 8 patients (38%). GCTs mostly occur at the epi-metaphysis in 11 patients (52.3%). Regardless of the openness of epiphyseal plate, we observed GCT of bone in the epiphysis. Further study will be needed to prove the association between the presence of epiphyseal plate and location of tumor. Three patients (21.4%) had multicentric lesions, and four patients (28.5%) had local recurrence. Multicentric giant cell tumor and local recurrence occur more often in pediatric patients. The characteristics of GCT in pediatric patients do not differ from what is reported for GCT in adults.

Giant Cell Tumors of Bone in Patients Aged 18 Years Old or Younger: Imaging Features and Tumor Characteristics

Objective

The majority of giant cell tumors of bone (GCTB) occur in adult patients, especially between the ages of 20 and 40. This study aims to investigate the imaging features of GCTBs in pediatric patients and compare their characteristics with adult cases.

Methods

Fifty-seven cases of patients aged 18 years old or younger were retrospectively analyzed, accounting for 12.8% of GCTBs in the First Affiliated Hospital of Zhengzhou University from 2001 to 2019. One hundred twenty-six adult patients (19 years of age and older) with GCTB occurring in long tubular bones were also included in this study. The following clinical information was identified from the medical records: age, sex, and follow-up data. Imaging features were reviewed by two musculoskeletal radiologists. Patient characteristics and imaging features between the two groups were compared.

Results

A total of 57 patients (32 females, 25 males) were included in the study. The patients’ ages ranged from 9 to 18 (median = 17 y). The majority of tumors occurred in tubular bones (n = 38, 66.7%) and the pelvis (n = 8, 14.0%). Imaging features were identified in GCTB cases occurring in the long tubular bones. Compared with adult GCTB patients, pediatric GCTB patients had a larger superior–inferior (SI) diameter (P = 0.005) and smaller left-to-right diameter/SI diameter ratio (P = 0.001). Epiphyseal involvement was relatively less common in pediatric patients with GCTBs than in adult patients (P = 0.009). The median age of patients without epiphyseal involvement was lower than the median age of patients with epiphyseal involvement (11 vs 17 y).

Conclusion

GCTB in the pediatric age group is rare. This study has found that, in pediatric patients with GCTBs, the epiphysis is relatively less involved, and the tumor is more likely to grow longitudinally. These findings are helpful in the diagnosis of GCTBs in the pediatric population.

Radiological Features of Giant Cell Tumours of Bone

Introduction

The aim of this study was to evaluate radiological measurements to establish the origin of giant cell tumours of bone.

Methods

A multi-centre retrospective review was conducted of patients with histologically confirmed giant cell tumours of bone. Images were analysed to estimate the centre of the tumour. Measured from the joint line, the ratio between the distance of the centre of the tumour and the physeal scar was calculated.

Results

Ninety-five patients were included in the study. Two observers found the tumour to be arising from the metaphyseal area in 94% - 97% of the cases. There was good agreement between the measurements of observers (interclass correlation coefficient 0.71).

Conclusion 

Giant cell tumours of bone appear to be arising from the metaphyseal region.

Can Giant Cell Tumor of the Bone Occur in the Skeletally Immature?

Giant cell tumor (GCT) of the bone is a benign, locally aggressive neoplasm that has a high tendency for local recurrence. It usually has a higher incidence in the third decade of life. This is a retrospective review of a case with histologic confirmation of GCT in a skeletally immature patient involving the metatarsal bone, which is a rare site. At our institution, 1.3% of skeletally immature patients had GCT of the bone. From an extensive literature review, only four cases of GCT of the metatarsal bone in the skeletally immature were identified. Giant cell tumor in a skeletally immature patient can be confused for an aneurysmal bone cyst because of similar radiologic findings. Giant cell tumor of the bone can occur in an immature skeleton and should be sought out as a differential diagnosis despite being rare.

Clinical features and prognostic factors of pediatric spine giant cell tumors: report of 31 clinical cases in a single center

BACKGROUND CONTEXT

Giant cell tumors (GCTs) of the bone are benign but locally aggressive. Pediatric spine giant-cell tumors (PSGCTs) have been infrequently reported in the literature because of the rarity of the disease.

PURPOSE

The purpose of this study was to define the overall occurrence rate of PSGCTs among all spinal GCTs in our center and investigate the clinical features and prognostic factors of this rare disease.

STUDY DESIGN

A retrospective review.

PATIENT SAMPLE

Thirty-one PSGCT patients, screened from 226 patients with spine GCTs who received treatment in our center between 1998 to 2017.

OUTCOME MEASURES

The clinical symptoms, neurologic status, radiologic manifestations, treatment, outcome, and complications were recorded and analyzed.

METHODS

The postoperative recurrence-free survival (RFS) rate was estimated by the Kaplan-Meier method. Factors with p values ≤.1 were subjected to multivariate analysis for RFS by proportional hazard analysis, among which p values ≤.05 were considered statistically significant.

RESULTS

A total of 31 (31 of 226, 13.7%) PSGCTs patients (9 male and 22 female) were included in the study, with a mean age of 15.9 years and a mean follow-up period of 85.1 (median 84.0; range 12-221) months. The majority of patients (80.6 %) were 14-18 years of age. Recurrence was detected in 12 (38.7%) of the 31 patients. Univariate and multivariate analyses suggested that Jaffe grade II-III was an adverse prognostic factor for RFS, while total spondylectomy and bisphosphonate treatment were positive prognostic factors.

CONCLUSIONS

Total en bloc spondylectomy (TES) is associated with excellent prognosis for PSGCTs, and total piecemeal spondylectomy is a viable alternative if total en bloc spondylectomy is unfeasible. Long-term bisphosphonate administration could significantly reduce the recurrence risk of PSGCTs. Denosumab treatment is recommended, especially for advanced PSGCTs. Jaffe grade II-III is an adverse prognostic factor for recurrence.

Histologic Spectrum of Giant Cell Tumor (GCT) of Bone in Patients 18 Years of Age and Below: A Study of 63 Patients

Although the majority of giant cell tumors (GCTs) of the bone occur in adult patients, occasionally they arise in the pediatric population. In this setting they may be mistaken for tumors more commonly seen in this age group, including osteosarcoma, aneurysmal bone cyst, and chondroblastoma. All cases of primary GCT of the bone arising in patients 18 years and below were retrieved from our institutional archives and examined with emphasis on the evaluation of various morphologic patterns. Clinical/radiologic records were reviewed when available. Analysis for H3F3A/H3F3B mutations was performed in a subset of cases. Sixty-three (of 710) patients treated at our institution for GCT were 18 years of age and below. The following morphologic patterns were identified: fibrosis (31 cases, 49%), reactive-appearing bone (26, 41%), cystic change (7, 11%), foamy histiocytes (6, 10%), secondary aneurysmal bone cyst (3, 5%), and cartilage (2, 3%). Infarct-like necrosis was present in 17 tumors (27%), and the mitotic rate ranged from 0 to 35 mitoses/10 high-power fields (median 5 mitoses/10 high-power field). Follow-up information (n=55; 6 mo to 69.6 y; median, 11.6 y) showed 21 patients with local recurrence (38%) and 2 patients with lung metastasis (4%). Polymerase chain reaction with sequencing showed that 5 of 5 tested cases harbored H3F3A mutations. In summary, GCT arising in the pediatric population is rare, representing 9% of GCTs seen at our institution. The morphologic spectrum of these tumors is broad and similar to that seen in patients above 18 years of age. It is important to recognize that matrix formation may be observed in GCT, including reactive-appearing bone and cartilage, as well as areas of fibrosis mimicking osteoid production, to avoid misclassification as osteosarcoma or other giant cell-rich lesions common in children.

Giant Cell Tumor: A Rare Condition in the Immature Skeleton-A Retrospective Study of Symptoms, Treatment, and Outcome in 16 Children

Background. Pediatric giant cell tumor (GCT) of bone is rare and the course of the disease in the immature skeleton is sparsely described. We performed a retrospective study addressing symptoms, treatment, and outcome in children with GCT. Methods. Review of medical records and images of patients with GCT. Patients were detected from our hospital prospective database and those with open epiphyseal cartilages were included. Results. 16 children (75% girls) from 6 to 15 years old were identified. Eight lesions (50%) were in long bones and 4 (25%) in flat bones. One lesion appeared to be purely epiphyseal. All patients had pain as the initial symptom. Local recurrence developed in 2 patients. 14 of 16 patients returned to normal activity with no sequelae. One patient developed anisomelia after surgery. Conclusions. The biological tumor behavior in children does not seem to differ from what is reported in adults. Lesions in flat bones are very unusual, but our data alone do not provide enough evidence to conclude that this is more common in the immature skeleton. Literature review showed only one previous case report describing a purely epiphyseal GCT. Intralesional curettage is appropriate treatment and gives good functional results with acceptable recurrence rates.

Giant Cell Tumor of Bone: Documented Progression over 4 Years from Its Origin at the Metaphysis to the Articular Surface

The exact location of origin for giant cell tumors of bone (GCTB) remains controversial, as lesions are not routinely imaged early but rather late when the tumor is large and clinically symptomatic. At the time of diagnosis, GCTB are classically described as lucent, eccentric lesions with nonsclerotic margins, located within the epiphysis to a greater extent than the metaphysis. Here we present a case of a biopsy proven GCTB initially incidentally seen on MRI as a small strictly metaphyseal lesion, which over the course of several years expanded across a closed physis to involve the epiphysis and abut the articular surface/subchondral bone plate.

Rapidly growing giant cell tumor of bone in a skeletally immature girl

Giant cell tumor of bone (GCTB) in skeletally immature patients is rare, and little is known regarding how fast GCTB can grow. We report a case of a 10-year-old skeletally immature girl with pathologically proven GCTB with obvious growth plate invasion that showed surprisingly rapid growth over only 14 days. A radiograph of the left knee revealed well-circumscribed, geographic bone destruction at the distal metaphysis of the femur with a focal cortical defect, suggesting a pathologic fracture. No abnormal mineralization or periosteal reaction was seen. A CT without contrast and an MRI demonstrated a homogeneous lesion with cortical disruption posteriorly and laterally with a slight soft tissue extension. Biopsy showed numerous multinucleated giant cells and spindle-shaped mononuclear cells without any sign of malignancy, suggesting GCTB. However, rapid lesion enlargement and destruction of the surrounding cortex were noted 14 days after biopsy. Considering the amount of bone destruction, traditional treatment of curettage and bone cement would not suffice to sustain structural strength. In addition, considering the patient's age, the tumor location, and the aggressive course, a malignant tumor, especially a giant cell-rich osteosarcoma, could not be excluded. Therefore, en bloc resection, including the growth plate and prosthetic replacement, were performed. Confirmation of GCTB was made from a pathologic evaluation, and a breach to the growth plate was identified. Since very little inflammatory reaction, degenerative change, or aneurysmal, bone, cyst-like change was found, the growth plate invasion was confirmed as due to GCTB extension, not due to the preoperative biopsy.

Giant cell tumor of bone arising in long bones possibly originates from the metaphyseal region

Giant cell tumor of bone (GCTB) is a primary benign bone tumor with a locally aggressive character. Definitive descriptions of the site of origin for this type of tumor are not available. The aim of the present study was to evaluate the site of origin of GCTB of long bones with regards to epiphyseal lines by means of radiographic examination. For that purpose, plain X-ray scans of 71 GCTBs arising in long bones were retrospectively reviewed. The tumor locations were the distal femur in 31 cases, proximal femur in 11 cases, proximal tibia in 13 cases, distal radius in 6 cases, proximal humerus in 5 cases and proximal fibula in 5 cases. The vertical center (VC) of the tumor was determined with X-ray anteroposterior view, and the correlation between the VC and the epiphyseal line, and between the distance from the epiphyseal line to the VC and tumor area or volume were analyzed using a regression model equation based on scatter plot diagrams. The VC of the tumor was located in the metaphyseal region in 57 cases, in the epiphyseal line in 11 cases and in the epiphyseal region in 3 cases. In cases of GCTB located in the distal femur or proximal tibia, significant correlations between the distance from the VC to the epiphyseal line and tumor area or volume were identified. The site of origin of GCTB was estimated to be located in the metaphyseal region. GCTB often occurs in mature patients, which renders it challenging to estimate the true site of origin of this lesion, since the metaphyseal line has disappeared in mature patients. The results of the present study suggest that GCTB possibly originates in the metaphyseal region.

The hypermetabolic giant: 18F-FDG avid giant cell tumor identified on PET-CT

An 87 year-old white female presented with a two-year history of intermittent discomfort in her left foot. PET-CT identified intense18F-fluorodeoxyglucose (FDG) uptake corresponding to the lesion. Histology of a fine needle aspiration and open biopsy were consistent with a benign giant cell tumor (GCT) of the bone. GCT of bone is an uncommon primary tumor typically presenting as a benign solitary lesion that arises in the end of the long bones. While GCT can occur throughout the axial and appendicular skeleton, it is exceedingly uncommon in the bone of the foot. While 18F-FDG has been established in detecting several malignant bone tumors, benign disease processes may also be identified. The degree of 18F-FDG activity in a benign GCT may be of an intensity that can be mistakenly interpreted as a malignant lesion. Therefore, GCT of the bone can be included in the differential diagnosis of an intensely 18F-FDG-avid neoplasm located within the tarsal bones.

The multidisciplinary management of giant cell tumor of bone

Giant cell tumor of bone is a locally aggressive lesion with a predilection for local recurrence, and in a small proportion of patients, metastatic disease can develop. Surgery is the mainstay of management for extremity-based lesions. For tumors located in challenging anatomical locations such as the sacrum and spine however, surgery may be associated with unacceptable functional morbidity. There are limited data regarding other treatment modalities such as radiation therapy, cytotoxic chemotherapy, interferon and bisphosphonates. Serial arterial embolization can be effective in some cases. Recent evidence has demonstrated denosumab to be a promising agent in the treatment of unresectable or metastatic disease.

Giant cell tumor of bone in childhood: clinical aspects and novel therapeutic targets

Giant cell tumor of bone (GCTB) is a rare primary bone tumor that primarily affects young adults, but can be seen in children. The primary modality of treatment is surgical resection; however, this is not always possible given the location and extent of the neoplasm. Recent developments in the understanding of the underlying molecular pathogenesis of disease have pointed to interactions between the stromal component producing receptor activator of nuclear factor-kappaB (RANK) and RANK-ligand (RANKL) causing the formation of osteoclast-like giant cells that drive bone destruction. The development of a monoclonal humanized antibody to RANKL, denosumab, has been shown to reduce skeletal-related events from osteoporosis and from bony metastases from solid tumors. Recent phase II clinical trials with denosumab in skeletally mature adolescents over age 12 years and adults with GCTB, have shown both safety and efficacy, leading to its accelerated US FDA approval on 13 June 2013. In children who are skeletally immature, safety and efficacy has not been established, and there has been only published anecdotal use.

Multicentric giant cell tumor in adolescents: three case reports

The presentation of multicentric giant cell tumor in adolescents with an open physis is very rare. We report three cases of a multicentric giant cell tumor of the bone in adolescents, and a review of the literature is also presented.

Giant cell tumor of the distal phalanx of the biphalangeal fifth toe: a case report and review of the literature

Giant cell tumor of the distal phalanx of a toe is rather unusual. We report an unusual case of giant cell tumor arising at the distal phalanx of the left biphalangeal fifth toe in a 13-year-old boy. This was treated successfully with curettage and packing with bone substitution.

Metatarsal giant cell tumor in adolescents

Level of Evidence: V, Expert Opinion

Giant cell tumour in the foot of a skeletally immature girl: a case report

We present a case of delayed diagnosis of a benign giant cell tumour (GCT) of the third metatarsal in a skeletally immature girl. The patient underwent en bloc excision of the tumour. The tumour had replaced the third metatarsal and had infiltrated the surrounding soft tissue and the second and fourth metatarsal bases. Deep, lateral and medial margins were all involved. A high index of suspicion is needed when evaluating any tumours of the foot, because the compact structure of the foot may delay diagnosis. Early detection is important for avoiding amputation, as the hindfoot and midfoot are classified as one compartment and radical resection is impossible to achieve. Tumours grow faster in the foot than in other bones. GCT in this location and age-group are rare and should be considered in the differential diagnosis of a destructive bony lesion in skeletally immature patients.

Epiphyseal giant cell tumour in an immature skeleton

It is well known that giant cell tumours of the bone rarely occur below the age of 20 years. Many radiologists and orthopaedicians do not even consider giant cell tumours as a differential diagnosis from a lytic lesion before epiphyseal closure. This is a rare case report of a 14-year-old girl with proven giant cell tumour of the epiphysis of the distal femur.

Giant cell tumor of bone in children and adolescents

BACKGROUND

There are very few series that document giant cell tumor of bone (GCT) in the immature skeleton, and the reported incidence in literature varies from 1.8% to 10.6%. The purpose of this study was to document the incidence of GCT in patients with open physis in the Indian population and study the course of the disease with respect to its adult counterpart to see if it behaved any differently.

METHODS

Between January 2000 and December 2005, 17 (6%) of 285 surgically treated patients with histologically proven GCT had open physis on imaging. Treatment was directed toward local control without sacrificing joint function, with most lesions treated with intralesional curettage.

RESULTS

Fourteen (82%) patients were girls. The most common site was around the knee (53%). Of 15 lesions in tubular bones, 13 were epiphysiometaphyseal in location. An open physis did not prevent GCT from penetrating the epiphyseal cartilage. Histologically, the tumors were typical of GCT. Of 15 patients available for follow-up, 3 (20%) developed local recurrence.

CONCLUSIONS

Although the overall incidence of GCT may be higher in the Asian population, the percentage of skeletally immature patients or those nearing skeletal maturity is similar to that described in literature. The biological behavior of the disease is similar to that seen in adults, except a marked female preponderance, principles of treatment, recurrence patterns, and course of the disease mirror the behavior of its adult counterpart.

Giant-cell tumours of bone of the hand and wrist: a review of imaging findings and differential diagnoses

Giant-cell tumour of bone (GCTOB) is a benign, locally aggressive, primary bone tumour. Involvement of the distal radius accounts for between 10 and 12% of cases of GCTOB, with the bones of the hand and wrist being rarely affected. GCTOB most commonly affects skeletally mature patients between the ages of 20 and 40 years, with the peak incidence being in the third decade. Women are affected slightly more commonly than men. GCTOB involving the bones of the hand most commonly occurs in a central location, which differs from the usual eccentric location seen in GCTOB at other sites. The radiographic features of GCTOB in the hand and wrist are presented. The role of bone scintigraphy, computed tomography and magnetic resonance imaging is discussed. Evaluation of the postoperative patient is also addressed, including the role of dynamic contrast-enhanced magnetic resonance imaging. A comprehensive review of the potential differential diagnoses that should be considered when GCTOB is suspected in the hand and wrist is also presented.

From the archives of AFIP. Imaging of giant cell tumor and giant cell reparative granuloma of bone: radiologic-pathologic correlation

The radiologic features of giant cell tumor (GCT) and giant cell reparative granuloma (GCRG) of bone often strongly suggest the diagnosis and reflect their pathologic appearance. At radiography, GCT often demonstrates a metaepiphyseal location with extension to subchondral bone. GCRG has a similar appearance but most commonly affects the mandible, maxilla, hands, or feet. Computed tomography and magnetic resonance (MR) imaging are helpful in staging lesions, particularly in delineating soft-tissue extension. Cystic (secondary aneurysmal bone cyst) components are reported in 14% of GCTs. However, biopsy must be directed at the solid regions, which harbor diagnostic tissue. These solid components demonstrate low to intermediate signal intensity at T2-weighted MR imaging, a feature that can be helpful in diagnosis. Multiple GCTs, although rare, do occur and may be associated with Paget disease. Malignant GCT accounts for 5%-10% of all GCTs and is usually secondary to previous irradiation of benign GCT. Treatment of GCT usually consists of surgical resection. Recurrence is seen in 2%-25% of cases, and imaging is vital for early detection. Recognition of the spectrum of radiologic appearances of GCT and GCRG is important in allowing prospective diagnosis, guiding therapy, and facilitating early detection of recurrence.

Malignant and benign bone tumors

The authors have intentionally included some confusing examples to demonstrate that the imaging findings of benign and malignant pediatric bone lesions are not always pathognomonic. The radiologist's role is to recognize malignant bone lesions and encourage the prompt referral of these patients to an appropriate institution for biopsy and treatment. The radiologist must also be able to identify benign lesions and help determine whether these lesions require biopsy and intervention or simply observation.

Giant cell reparative granuloma: a comparative clinicopathologic study of lesions in gnathic and extragnathic sites

This study attempts to define the clinicopathologic aspects of extragnathic giant cell reparative granuloma (GCRG) by contrasting it with the much better recognized GCRG of jaw bones and highlights the manifestations that are unique to the extragnathic localization. Ninety-one GCRGs of 89 patients, 22 in jaw bones and 69 in the extragnathic bones, were examined. Females were affected twice as frequently as males in both groups. The age distribution of extragnathic GCRGs overlaps that of gnathic counterparts. Small bones of the hands (17 lesions) and feet (16 lesions) were the most common sites for extragnathic lesions. The radiographic findings were nonspecific. Histology of extragnathic lesions was closely similar to that of lesions affecting the jaw. These giant cell lesions should be distinguished from giant cell tumors. Int J Surg Pathol 9(3):189-200, 2001

Giant cell tumor in the skull of a 9-year-old child: immunohistochemistry to confirm a diagnosis rare for age and site

Giant cell tumor of the bone is usually located within the epiphysis of a long bone, the majority of the lesions occurring in the third and fourth decades of life. We report an unusual case of giant cell tumor (GCT) arising in the parietal skull bone of a 9-year-old girl. The tumor exhibited histologic findings typical for GCT, with conspicuous intravascular giant cells. Based on microscopic features, not only conditions like aneurysmal bone cyst or bone changes associated with hyperparathyroidism but also tumors such as chondroblastoma or osteosarcoma had to be considered. Immunohistochemistry revealed strong reactivity of the tumor giant cells and normal bone osteoclasts with CD68 but not Mac-387; tumor stromal cells were uniformly negative for both. The stromal cells exhibited two immunohistochemically distinct phenotypes. One, involving 50-80% of the tumor cells, exhibited negative lysozyme staining with positivity of proliferating cell nuclear antigen (PCNA) in about 30% of the nuclei. The other showed reactivity with lysozyme but negative PCNA staining. Immunohistochemistry thus helped to distinguish chondroblastoma and osteosarcoma, in which lysozyme positivity would reside in macrophages but not within stromal cells. Instead, chondroblastoma would exhibit protein S-100 positivity in the tumor cells. The biological behavior of GCT is difficult to predict based on morphology alone, although the malignant potential seems to rest in the stromal cells rather than the giant cells. Specifically, in reported cases, the intravascular occurrence of giant cells in GCT is not associated with an increased incidence of metastasis.

Magnetic resonance imaging of musculoskeletal tumors

In summary, MRI is the preferred modality for the evaluation of a soft-tissue mass following radiography. The radiologic appearance of certain soft-tissue tumors or tumor-like processes such as benign fatty tumors, intramuscular hemangiomas, pigmented villonodular synovitis, and certain hematomas may be sufficiently unique to allow a strong presumptive radiologic diagnosis. It must be emphasized that MRI cannot reliably distinguish between benign and malignant lesions and, when radiologic evaluation is nonspecific, one is ill advised to suggest a lesion is benign or malignant solely on its MR appearance. The role of MRI in the evaluation of bone tumors is predominantly one of staging. MRI is superb to evaluate the extent of intraosseous and soft-tissue involvement as well as the relationship of the lesion to the neurovascular bundle. Unfortunately, MRI remains nonspecific and is unable to predict lesion histology. Finally, the value of Gd-DTPA enhanced imaging is still to be determined.

Multicentric giant cell tumor: report of five new cases

The typical giant cell tumor (GCT) is a solitary neoplams that occurs in the epiphysis or epimetaphysis of long bones. GCT is seen with a slightly increased frequency in females, and 70% of patients are between 20 and 40 years of age at the time of presentation. Multicentric giant cell tumor (MGCT; two or more centers) is an unusual variant of GCT. Patients with MGCT are likely to be younger than those with a solitary lesion. The multicentric variety is often of a higher stage at diagnosis and is more often associated with a pathological fracture than the unifocal tumor. We are reporting five new cases of MGCT, with a total of 21 tumors seen over a period of 25 years from 1967 to 1992.

Giant cell tumor in children and adolescents

The radiological appearance of giant cell tumors (GCT) in the developing skeleton was retrospectively assessed in 49 (10.6%) of the 462 patients with GCTs seen in consultation by the Netherlands Committee on Bone Tumors. There were 31 female and 18 male patients, all below 19 years of age. Thirty-four tumors were located in short and long tubular bones, two in the tarsus, while the others were in the pelvis, vertebral spine, and a rib. Involvement of the epiphysis in tubular bones was closely related to the age of the patient: the average age of the 3 patients with a lesion in the metaphysis was 11 years, that in the 6 patients with metadiaphyseal lesions 13 years, average age in the 10 patients with epimetaphyseal lesions 17 years, and it was also 17 years in the 17 patients with epimetadiaphyseal lesions. In tubular bones with the epiphyseal growth plates still open, the epiphysis was never involved, with the exception of two epimetadiaphyseal lesions in which closure of the growth plate was difficult to establish. Assessing GCT characteristics in this study population demonstrated that epiphyseal involvement increased with age and showed; to some extent, a predominance of female patients.