Chondroblastoma: MR characteristics with pathologic correlation

Bone metastases from chondroblastoma: a rare pattern of metastatic disease in an adult

Chondroblastoma is a rare benign tumor, typically presenting in the first two decades. Systemic metastases in chondroblastoma are extremely rare and it is the rarity of these metastases which lead the World Health Organisation to re-classify this lesion from "intermediate" to "benign" in its updated classification of bone tumors in 2020. We present an unusual case of a 55 year-old male patient who presented with multiple FDG-avid bone lesions on a background of conventional chondroblastoma of the rib excised at another institution 11-years previously. Two of these lesions were also histologically-proven as conventional chondroblastoma at biopsy. This case highlights that, although rare, metastases can be seen in patients with chondroblastoma. To our knowledge, this is the only case with an unusual pattern of metastases limited to bone.

Recurrent chondroblastoma of the acetabulum in an adult

Chondroblastoma is a rare, benign neoplasm of chondroblast cell origin, accounting for less than 1% of primary bone tumors. It is usually diagnosed in the second decade of life with most of the cases involving the long bones such as the femur and humerus. Furthermore, over 90% of cases are in individuals under 30 years of age. In older adults, chondroblastomas are typically found in bones in the foot, such as the talus and calcaneus. Treatment is usually local curettage of the lesion with a relatively low rate of recurrence. In this case report, we present a patient with an atypical age of initial presentation at 49 years, a rare location of the chondroblastoma in the acetabulum, and a recurrence 14 years after surgical resection in the same location. The lesion's radiographic findings of intralesional calcifications alongside the high-signal, heterogeneous composition on T2-weighted MRI were supportive of the atypical diagnosis of chondroblastoma in this patient.

A rare case of chondroblastoma involving the distal phalanx of the ring finger

Chondroblastoma, a rare benign bone tumor, is typically found in the epiphysis of long bones, with hand involvement being particularly uncommon. We present a case of an 11-year-old female with chondroblastoma involving the fourth distal phalanx of the hand. Imaging revealed a lytic, expansile lesion with sclerotic margins and no soft tissue component. A preoperative differential diagnosis included intraosseous glomus tumor, epidermal inclusion cyst, enchondroma, and chronic infection. The patient underwent open surgical biopsy and curettage for both diagnostic and treatment purpose. The final histopathologic diagnosis was chondroblastoma.

Malignant Bone Tumors Diagnosis Using Magnetic Resonance Imaging Based on Deep Learning Algorithms

Background and Objectives: Malignant bone tumors represent a major problem due to their aggressiveness and low survival rate. One of the determining factors for improving vital and functional prognosis is the shortening of the time between the onset of symptoms and the moment when treatment starts. The objective of the study is to predict the malignancy of a bone tumor from magnetic resonance imaging (MRI) using deep learning algorithms. Materials and Methods: The cohort contained 23 patients in the study (14 women and 9 men with ages between 15 and 80). Two pretrained ResNet50 image classifiers are used to classify T1 and T2 weighted MRI scans. To predict the malignancy of a tumor, a clinical model is used. The model is a feed forward neural network whose inputs are patient clinical data and the output values of T1 and T2 classifiers. Results: For the training step, the accuracies of 93.67% for the T1 classifier and 86.67% for the T2 classifier were obtained. In validation, both classifiers obtained 95.00% accuracy. The clinical model had an accuracy of 80.84% for training phase and 80.56% for validation. The receiver operating characteristic curve (ROC) of the clinical model shows that the algorithm can perform class separation. Conclusions: The proposed method is based on pretrained deep learning classifiers which do not require a manual segmentation of the MRI images. These algorithms can be used to predict the malignancy of a tumor and on the other hand can shorten the time of their diagnosis and treatment process. While the proposed method requires minimal intervention from an imagist, it needs to be tested on a larger cohort of patients.

Chondroblastoma of mandibular condyle: Case report and literature review

Chondroblastoma is one of the uncommon benign bone tumors, particularly when located in the mandibular condyle. Such a location makes its diagnosis difficult when based on only its clinical presentation and radiographic features. Herein the current report presents a case of chondroblastoma of the mandibular condyle: its clinical presentation, radiographic features, and immediate condylar reconstruction after resection. Additionally, the relevant literature is discussed to provide clinical recommendations for its diagnosis and treatment. Chondroblastoma has been reported so infrequently in the temporomandibular joint (TMJ), more common entities should first be considered in the differential diagnosis of masses in this location. Osteochondroma is the most frequent bone neoplasm in the TMJ. Since a correct diagnosis is difficult, additional tools, such as magnetic resonance imaging (MRI) and immunohistochemical analyses, should be used for diagnostics and surgical planning.

Total Calcanectomy and Bilateral Iliac Bone Autograft Reconstruction for the Treatment of Calcaneal Chondroblastoma Involving a Secondary Aneurysmal Bone Cyst: A Case Report and Literature Review

Chondroblastoma is a rare, benign, cartilaginous-derived tumor accounting for ∼1% to 2% of all primary bone tumors and almost 9% of all benign bone tumors. In this case report, we describe a patient with chondroblastoma and a secondary aneurysmal bone cyst, with the adjacent talus being mildly affected. The initial diagnosis was giant cell tumor and was then confirmed after computed tomography-assisted biopsy. We performed a total calcanectomy via bilateral structural iliac bone autografting to relieve pain and reconstruct the loadbearing function because of the presence of extensive lesions. The patient was pain free and expressed satisfaction with postsurgical dorsiflexion and plantarflexion function at the 60-month follow-up visit. Radiographic images showed that the autografted iliac bone was completely healed, with no evidence of local recurrence.

Epithelioid hemangioma of bone: radiologic and magnetic resonance imaging characteristics with histopathological correlation

BACKGROUND

Epithelioid hemangioma is a rare vascular tumor that can occur in soft tissues or bone. The tumor is part of a spectrum of vascular tumors that also includes epithelioid hemangioendothelioma and angiosarcoma. When involving the bone, the tumor usually involves the metaphysis or diaphysis of the long tubular bones and most commonly occurs in adults. It has been rarely reported in pediatric patients, and in these reported patients, the tumor primarily involves the epiphysis.

OBJECTIVE

To review three cases of epithelioid hemangioma of bone occurring in pediatric patients involving the epiphysis and to explore the imaging features of this tumor.

MATERIALS AND METHODS

Retrospectively review three cases of epithelioid hemangioma occurring in skeletally immature patients.

RESULTS

These tumors primarily involved the epiphyses or epiphyseal equivalent bones. One lesion was centered in the metaphysis but extended to the epiphysis. These are three cases presenting in an unusual location and at an unusual age.

CONCLUSION

Epithelioid hemangioma, though rare, can occur in pediatric patients and appears to involve the epiphyses in these patients. This is in contrast to the usual age and location reported. Epithelioid hemangioma may be considered for an epiphyseal lesion in a skeletally immature patient.

Chondroblastoma: An Update

Chondroblastoma is a rare primary bone tumor of young people that typically arises in the ends of the long bones. Radiologic investigations show a small, circumscribed, lytic lesion. The tumor is characterized histologically by the proliferation of chondroblasts along with areas of mature cartilage, giant cells, and occasionally, secondary aneurysmal bone cyst formation. Chondroblastoma, however, may also present with atypical features, such as prominent hemosiderin deposition, numerous giant cells, or the presence of a large aneurysmal bone cyst component. Malignant entities such as clear cell chondrosarcoma and chondroblastic osteosarcoma must also be considered. Recently, immunohistochemical stains such as DOG1 and SOX9 have been described in chondroblastoma, and K36M mutations in either the H3F3A or H3F3B genes have also been identified. While generally regarded as a benign entity, chondroblastoma manifests an intermediate type of behavior, given its ability to recur locally, and rarely, metastasize.

Chondroblastoma-like osteosarcoma: a case report and review

Chondroblastoma-like osteosarcomas are extremely rare malignancies having varying clinical, radiological and histological features. Their rarity causes challenges in both diagnosis and clinical management. They are often misdiagnosed as benign lesions. Their accurate diagnosis is important because they require adequate treatment. Misdiagnosed lesions or undertreatment may result in recurrences. We report a case of chondroblastoma-like osteosarcoma arising in the left first metatarsal bone with tarsometatarsal joint involvement in a 10-year-old boy for whom surgery with an original technique was planned after a multidisciplinary diagnostic review.

Calcaneal chondroblastoma with pathologic fracture and recurrence

Chondroblastomas account for <2% of all bone tumors. The calcaneus is the fifth most common location of occurrence. Males in their second decade of life are most often affected, presenting with an insidious onset of localized pain, swelling, and tenderness. The finding of associated pathologic fracture has been rare. Imaging studies can aid in the formulation of the differential diagnosis and surgical plan. The definitive diagnosis requires histologic examination. Curettage and bone grafting is curative in >80% of cases. Local recurrence rates of ≤38% have been reported, most often because of inadequate resection, and have been associated with malignant conversion and metastasis. Adjuvant therapies can help minimize the incidence of local recurrence. Long-term follow-up examinations are recommended, given the protracted interval that can exist between recurrence and the potential for malignant conversion and metastasis. We present the case of a young, healthy, active male with a calcaneal chondroblastoma and associated pathologic fracture whose initial treatment consisted of curettage, hydrogen peroxide lavage, and allogeneic bone grafting. Recurrence developed at 15 months postoperatively and was treated with repeat curettage, high-speed burring, and reconstruction with steel Steinman pins and polymethylmethacrylate, resulting in no pain or recurrence at the 5-month follow-up point.

The role of magnetic resonance imaging in the evaluation of bone tumours and tumour-like lesions

Bone tumours and tumour-like lesions are frequently encountered by radiologists. Although radiographs are the primary screening technique, magnetic resonance imaging (MRI) can help narrow the differential or make a specific diagnosis when a lesion is indeterminate or shows signs of aggressiveness. MRI can extend the diagnostic evaluation by demonstrating several tissue components. Even when a specific diagnosis cannot be made, the differential diagnosis can be narrowed. MRI is superior to the other imaging modalities in detecting bone marrow lesions and tumoral tissue (faint lytic/sclerotic bone lesions can be difficult to visualise using only radiographs). Contrast-enhanced MRI can reveal the most vascularised parts of the tumour and MRI guidance makes it possible to avoid biopsing necrotic areas. MRI is very helpful in local staging and surgical planning by assessing the degree of intramedullary extension and invasion of the adjacent physeal plates, joints, muscle compartments and neurovascular bundles. It can be used in assessing response to neoadjuvant therapy and further restaging. The post-therapeutic follow-up should also be done using MRI. Despite the high quality of MRI, there are a few pitfalls and limitations of which one should be aware. Applications of MRI in bone tumours will probably continue to grow as new sequences are further studied.

TEACHING POINTS

• When a lesion is indeterminate or shows signs of aggressiveness, MRI is indicated. • When MRI does not lead to a diagnosis, biopsy is indicated. • MRI is superior to the other imaging modalities in detecting bone marrow lesions. • MRI is very helpful in local staging and surgical planning. • MRI is used in assessing the response to neoadjuvant therapy, restaging and post-therapeutic follow-up.

Primary aggressive chondroblastoma of the humerus: an unusual imaging presentation

Chondroblastoma is an uncommon primary benign cartilage-producing neoplasm representing only 1% of all primary bone neoplasia, with male preponderance. It has a predilection to present in any bone ossified in the endochondral pattern. Epiphyseal location, small size, geographic margins, and cartilaginous matrix are virtually pathognomonic radiologic features of this tumor. The tumor rarely transgresses the parent bone to invade adjacent structures. We describe a histologically proven case of chondroblastoma, invading the adjacent glenohumeral joint in a 15-year-old female presented with shoulder pain, in which radiological features belied the nature of the tumor.

A massive chondroblastoma in the proximal humerus simulating malignant bone tumors

Chondroblastoma is a mostly benign bone neoplasm that typically affects the second decade of life and exhibits a lytic lesion in the epiphysis of long bones. We report an extreme case of massive, destructive chondroblastoma of the proximal humerus in a 9-year-old girl. It was difficult to differentiate using imaging information the lesion from malignant bone tumors such as osteosarcoma. Histopathological examination from biopsy proved chondroblastoma. The tumor was resected after preoperative transcatheter embolization. Reconstructive procedure for the proximal humerus was not performed due to the local destruction. The present case demonstrates clinical and radiological differentiations of the massive chondroblastoma from the other lesions and histopathological understandings for this lesion.

The imaging of cartilaginous bone tumours. I. Benign lesions

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.

A rare case of epiphyseal chondromyxoid fibroma of the proximal tibia

Chondromyxoid fibroma is an uncommon benign cartilaginous tumor of the bone. It occurs most frequently in the metaphysis of long tubular bones, and an epiphyseal location is exceedingly rare. We present here an unusual case of a chondromyxoid fibroma that occurred in the epiphysis of the proximal tibia with an open growth plate. MR imaging findings of this tumor, which has, to the best of our knowledge, never been described in an epiphyseal location, makes the present case unique.

Radiologic diagnosis of osteoid osteoma: from simple to challenging findings

Osteoid osteoma is characterized by an intracortical nidus with a variable amount of calcification, as well as cortical thickening, sclerosis, and bone marrow edema. When these findings are present, a diagnosis of osteoid osteoma is easily made. However, osteoid osteoma may display imaging findings that can be misleading, and it can be difficult to differentiate osteoid osteoma from other conditions such as infection, inflammatory and noninflammatory arthritis, and other tumors. In addition, stress fracture, intracortical abscess, intracortical hemangioma, chondroblastoma, osteoblastoma, and compensatory hypertrophy of the pedicle may mimic osteoid osteoma. To make the correct diagnosis, it is necessary to identify the nidus, and it is important to be familiar with the radiologic findings of osteoid osteoma and its mimics.

A case of spine origin chondroblastoma metastasis to lung

Chondroblastoma is a rare benign cartilaginous neoplasm that accounts for approximately 1% of all bone tumors and characteristically arises in the epiphysis of a long bone, particularly the humerus, tibia, and femur. Chondroblastoma can affect people of all ages. It is, however, most common in children and young adults between the ages of 10 and 20 years. Although most chondroblastomas are cured by limited surgical procedures, occasional lesions behave more aggressively and may even metastasis. In this case a young man with pulmonary metastatic chondroblastoma on spine is presented. Unlike previously published examples of metastatic chondroblastoma, these metastasis developed before any operative manipulation of the primary tumor. And primary tumor site was also unusual. The histologic characteristics of the primary, metastatic tumors were those of a conventional chondroblastoma.

Imaging of back pain in children

While back pain presents less frequently in children than in adults, it still poses a significant clinical challenge with respect to making a firm diagnosis and developing an effective treatment plan. When children have back pain and medical attention is sought, an underlying pathology is usually suspected. Pediatric patients are evaluated, first, with a complete clinical history and examination and, second, by an imaging work-up that is based on initial findings, including the child's age and size, signs and symptoms, and suspected etiology. This article describes 1) the epidemiology of back pain in children, 2) the imaging work-up used, and 3) the correlation of imaging findings with disease entities that may cause back pain in the pediatric patient. The list of diseases giving rise to back pain is not meant to be exhaustive but rather reflective of the most commonly identified pathologies and disorders among young children and adolescents, from athletic injuries to lethal cancers.

MR imaging of primary bone tumors and tumor-like conditions in children

This article provides a review of the MR imaging features of the major primary malignant and benign bone tumors and tumorlike conditions encountered in the pediatric population. Malignant tumors discussed include osteosarcoma, Ewing sarcoma, chondrosarcoma, lymphoma, and malignant fibrous histiocytoma. Benign lesions discussed include simple bone cysts, aneurysmal bone cysts, giant cell tumor, osteochondroma, enchondroma, chondroblastoma, osteoid osteoma, osteoblastoma, nonossifying fibroma, fibrous dysplasia, osteofibrous dysplasia, hemangioma, and histiocytosis. The use of MR imaging in the diagnosis of these lesions is discussed, and the text is enhanced with imaging examples of the lesions.

Proximal tibial epiphyseal intraosseous schwannoma: a rare entity

Schwannoma is a benign nerve sheath tumor most commonly located in the soft tissue. Occasionally, schwannomas involve osseous structures. The rarity of osseous involvement leads to omission of schwannoma from the initial differential diagnosis in the majority of cases. Intraosseous schwannomas arising in children have not been reported. We present the case of a schwannoma affecting the proximal tibial epiphysis in a growing child. Intraosseous schwannomas should be included in the differential diagnosis of lytic epiphyseal benign-appearing bone lesions in children. Its radiographic characteristics mimic those of benign chondroblastoma.

Diagnostic imaging of solitary tumors of the spine: what to do and say

Metastatic disease, myeloma, and lymphoma are the most common malignant spinal tumors. Hemangioma is the most common benign tumor of the spine. Other primary osseous lesions of the spine are more unusual but may exhibit characteristic imaging features that can help the radiologist develop a differential diagnosis. Radiologic evaluation of a patient who presents with osseous vertebral lesions often includes radiography, computed tomography (CT), and magnetic resonance (MR) imaging. Because of the complex anatomy of the vertebrae, CT is more useful than conventional radiography for evaluating lesion location and analyzing bone destruction and condensation. The diagnosis of spinal tumors is based on patient age, topographic features of the tumor, and lesion pattern as seen at CT and MR imaging. A systematic approach is useful for recognizing tumors of the spine with characteristic features such as bone island, osteoid osteoma, osteochondroma, chondrosarcoma, vertebral angioma, and aneurysmal bone cyst. In the remaining cases, the differential diagnosis may include other primary spinal tumors, vertebral metastases and major nontumoral lesions simulating a vertebral tumor, Paget disease, spondylitis, echinococcal infection, and aseptic osteitis. In many cases, vertebral biopsy is warranted to guide treatment.

Chondroblastoma of the apex portion of petrousal bone

BACKGROUND

Skull chondroblastoma is extremely rare. We described in this study the first case of petrousal bone apex chondroblastoma.

METHODS

The tumor occurred in a 12-year-old girl and was revealed by left hypoacusis, vertigo, and walking instability. Computerized tomography scan depicted well-demarcated and osteolytic lesion of the left petrousal bone just before the internal acoustic meatus. The tumor was operated on by a subtemporal approach with a subtotal resection. Lesion recurred and was operated a second time by a combined approach subtemporal and translabyrinthine. This treatment was completed by radiotherapy. We used a combination of photon therapy and proton therapy. Outcome was good and free of recurrence 36 months after the second operation.

CONCLUSION

Proton therapy can be particularly useful for skull base tumors frequently radioresistant and near very important structures. This case is the first one of a successful treatment by proton therapy for chondroblastoma recurrence.

Condroblastoma de hueso temporal. Caso clínico y revisión de la literatura

We report a clinical case of a 31 year old male with a left temporal painful mass of six months evolution. After radiologic diagnosis, intraoperatory biopsy and surgical removal, the anatomopathological result confirmed the histology of chondroblatoma, with a satisfactory postoperative evolution. The chondroblastoma is a benign bone tumor typically located in the epiphysis of long bones and the temporal bone is an excepcional location as we have verified through a literature review.

Temporal bone chondroblastoma: a review

The objective of this paper was to review temporal bone chondroblastomas in regard to their presentation, radiographic findings, histopathology, and treatment. A case report of a 38-year-old man who presented with the left-sided hearing impairment and temporal swelling was reviewed. A CT scan revealed an osteolytic lobulated expansile mass. MRI depicted two cystic components with fluid-fluid level and enhanced solid mass. Immunohistochemical study of S-100 was performed using avidinbiotin-complex method. The tumor was totally removed, with eroded squamous bone and temporal muscle, via the left zygomatic-extended middle fossa approach. The pathology of the tumor showed that the tumor cell was spindle-shaped, along with multinucleated giant cells. These cells had oval to polygonal nuclei; some cells showed grooved nuclei. Intercelluar calcification and hemorrhagic components were also observed in the tumor. Tumor cells were strongly positive for S-100 protein. Temporal bone chondroblastomas are extremely rare osseous tumors with only 45 cases previously reported in the published literature. They may be confused with more common lesions seen in the temporal bone. Diagnostic radiology, including CT and/or MRI, as well as immunohistochemical staining with S-100 protein, may assist in making the diagnosis. Treatment is complete surgical excision with preservation of vital neurovascular structures.

Clear cell chondrosarcoma: radiographic, computed tomographic, and magnetic resonance findings in 34 patients with pathologic correlation

OBJECTIVE

To describe the radiographic features of clear cell chondrosarcoma (CCCS), including the computed tomographic (CT) and magnetic resonance (MR) findings, and to correlate them with the histopathologic findings.

DESIGN AND PATIENTS

A retrospective review was carried out of 72 patients with histopathologically confirmed CCCS. Imaging studies were available for 34 patients: conventional radiographs (n=28), CT scans (n=14), and MR images (n=15). Radiographic studies were reviewed by three radiologists who rendered a consensus opinion; the studies were correlated with the histopathologic findings.

RESULTS

Of the 34 patients with imaging studies, 30 were male and 4 were female (mean age 38.6 years; range 11-74 years). Twenty-two lesions were in long bones (15, proximal femur; 1, distal femur; 1, proximal tibia; 5, proximal humerus) and 11 were in flat bones (5, vertebra; 4, rib; 1, scapula; 1, innominate). One lesion occurred in the tarsal navicular bone. Typically, long bone lesions were located in the epimetaphysis (19/22) and were lucent with a well-defined sclerotic margin and no cortical destruction or periosteal new bone formation. More than one-third of the long bone lesions contained matrix mineralization with a characteristic chondroid appearance. Pathologic fractures were present in six long bone lesions (4, humerus; 2, femur). Lesions in the proximal humerus were more likely to have indistinct margins (4/5) and extend into the diaphysis. Flat bone lesions were typically lytic and expansile and occasionally demonstrated areas of cortical disruption. Typically, matrix mineralization, when present, was amorphous. MR imaging, when available, was superior to conventional radiographs for demonstrating the intramedullary extent of a lesion as well as soft tissue extension. CT images better delineated the presence of cortical destruction and the character of matrix mineralization patterns. CCCS lesions were typically low signal intensity on T1-weighted images and moderately or significantly bright on T2-weighted images. Areas of lesion heterogeneity on T1- and T2-weighted images and on post-gadolinium T1-weighted images corresponded pathologically to areas of mineralization, intralesional hemorrhage, and cystic changes. Adjacent bone marrow edema was typically absent (12/15) or only minimally observed in a few cases (3/15). No cases examined with MR imaging demonstrated periosteal new bone formation.

CONCLUSIONS

CCCS typically presents radiographically as a geographic lytic lesion located in the epimetaphyseal region of long bones. Most commonly lesions are found in the proximal femur, followed by the proximal humerus. Lesions within the proximal humerus may exhibit more aggressive features. Lesions in the axial skeleton are typically expansile and destructive, often with soft tissue extension and lack of mineralization. MR imaging may show the presence or absence of bone marrow edema.

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.