Imaging in osteofibrous dysplasia, osteofibrous dysplasia-like adamantinoma, and classic adamantinoma

The 2020 World Health Organization classification of bone tumors: what radiologists should know

Improved understanding of tumor biology through molecular alteration and genetic advances has resulted in a number of major changes in the 2020 World Health Organization's (WHO) classification of bone tumors. These changes include the reclassification of the existing tumors and the introduction of several new entities. A new chapter on undifferentiated small round cell sarcomas of bone and soft tissue was added to classify Ewing sarcoma and the family of Ewing-like sarcomas, which share similar histologies but different molecular and clinical behaviors. Knowledge of the current classification of bone tumors is essential to ensure the appropriate recognition of the inherent biological potential of individual osseous lesions for optimal treatment, follow-up, and overall outcome. This article reviews the major changes to the 2020 WHO's classification of primary bone tumors and the pertinent imaging of selected tumors to highlight these changes.

Comparison of MRI Findings among Osteofibrous Dysplasia, Fibrous Dysplasia, and NonOssifying Fibroma of the Long Bone

Background The characteristics of magnetic resonance imaging (MRI) findings among osteofibrous dysplasia (OFD), fibrous dysplasia (FD), and nonossifying fibroma (NOF) have yet to be determined.

Aims This study determines the differences of MRI features among OFD, FD, and NOF of the long bone.

Patients and Methods This study included 39 patients including 10 OFD, 13 with FD, and 16 with NOF of the long bone. All patients underwent preoperative MRI and histological examination. We retrospectively reviewed the MRIs and compared the imaging findings among the three pathologies.

Results The maximum diameter was significantly different among OFD (47.0 ± 18.6 mm), FD (59.0 ± 35.0 mm), and NOF (33.3 ± 15.0 mm) (p < 0.05). Multiplicity (60%, p < 0.01), eccentric distribution (100%, p < 0.05), septation (70%, p < 0.01), homogeneous intensity on T2-weighted images (70%, p < 0.01), homogeneous contrast enhancement (63%, p < 0.05), and intense contrast enhancement (88%, p < 0.01) were significantly more frequent in OFD. Centric distribution (69%, p < 0.01), cyst formation (54%, p < 0.01), and fluid-fluid level formation (31%, p < 0.01) were significantly more frequent in FD. Eccentric distribution (100%, p < 0.01), heterogeneous on T2-weighted images (100%, p < 0.01), predominant hypointensity on T2-weighted images (44%, p < 0.01), and the presence of intralesional hypointensity on T2-weighted images (88%, p < 0.01) were significantly more frequent in NOF.

Conclusion MRI features could differentiate OFD, FD, and NOF of the long bone.

Osteofibrous dysplasia-like adamantinoma: A case report and literature review

ABSTRACT BACKGROUND

Osteofibrous dysplasia-like adamantinoma (OFD-like adamantinoma), classical adamantinoma and dedifferentiated adamantinoma were previously considered to be three subtypes of adamantinoma of long bones. In the 5th edition of the World Health Organization (WHO) classification of bone tumors in 2020, OFD-like adamantinoma was newly proposed and classified as an intermediate-locally aggressive tumor in other mesenchymal tumors of bone. OFD-like adamantinoma is rare, accounting for only 0.4% of all primary bone tumors. OFD-like adamantinoma is often misdiagnosed due to the insufficient understanding of it. Here we report a case of OFD-like adamantinoma treated in our hospital with a literature review.

CASE PRESENTATION

The patient, a 14-year-old male, had swelling in his right leg with intermittent pain for one year. Plain radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. Based on the radiological and histological examinations, a diagnosis of OFD-like adamantinoma was suspected. After admission, the patient underwent tumor resection of the right tibia, free transplantation of the left fibula and internal fixation. After resection of the tumor, the wound recovered well, the vital signs were stable, and activity was normal. The patient has been followed up for more than a year with no recurrence or distant metastasis.

CONCLUSION

OFD-like adamantinoma is a rare primary bone tumor with nonspecific clinical features. Imaging examination can demonstrate the lesion and help diagnosis. The pathological discovery of epithelioid tissue is the key evidence for diagnosis.

Osteofibrous dysplasia-like adamantinoma of isolated fibula in a child mimicking chronic osteomyelitis with pathological fracture

The occurrence of a pathological fracture in children requires a rigorous diagnostic approach in order to establish the etiology and to develop a precise therapeutic strategy. Several causes are associated with these fractures, the most frequent being benign tumors in children in developed countries and chronic osteomyelitis in developing countries. More rarely, malignant tumors must however always be considered. The differential diagnosis on imaging may be difficult to establish between bone tumors and chronic infection. Surgical biopsy is therefore often performed to establish the precise origin of the fracture. We report the case of an adamantinoma (osteofibrous dysplasia-like) of the fibula in a 7-year-old child, discovered during the management of a pathologic fracture. The presumed diagnosis before biopsy was chronic osteomyelitis. A 14-cm-resection of the affected fibula was performed with good functional result. Differential diagnosis between adamantinoma, osteofibrous dysplasia and osteofibrous dysplasia-like adamantinoma remains very challenging.

Neonatal osteofibrous dysplasia: Synchronous tibial and fibular involvement is common

Osteofibrous dysplasia is a rare non-malignant fibro-osseous bone tumour, first described and characterised under this name by Campanacci in 1976. It is most commonly encountered in the tibia of children and young adults, but less frequently seen in the neonate with only few prior reports in the literature. We report a case of neonatal congenital osteofibrous dysplasia, presenting with unilateral limb deformity at birth. Radiographs demonstrated well-defined mixed lytic-sclerotic lesions, in a previously unreported distribution in this age-group, confined to the distal metadiaphysis of the affected tibia and fibula. Open surgery was performed for deformity correction, with tissue biopsy confirming the radiographically-suspected diagnosis. We present the up-to-date clinical, radiological and pathological findings in this case of a rare pathology with some novel features, within this age group, in disease distribution and consequent radiographic appearances. OFD should be considered in the differential of similar congenital deforming bone lesions of the lower limb. We also review the small number of previously published cases of congenital OFD in the neonate, noting in particular that the frequency of ipsilateral fibular involvement appears to be higher than that observed in older patients.

Osteofibrous dysplasia: A rare case in 3-day-old female

Osteofibrous dysplasia (OFD) is a nonneoplastic tumor-like lesion, made up of fibrous matrix with immature bone tissue surrounded by osteoblasts, occurring usually in the cortex of tibial diaphysis. OFD is usually seen in the first decade of life and, according to literature, it is rarely seen in the newborn period. Diagnosis of congenital OFD in the newborn is challenging because it is uncommon in this age group and can be confused with other bone benign or malignant lesions. Imaging plays an important role in diagnosis, although histological confirmation is often required. Our report presents a rare case of pathologically confirmed congenital OFD in 3-day-old female which presented with a swelling of her right leg. We will focus on imaging findings of OFD and main differential diagnosis of this lesion in neonatal age.

Osteofibrous dysplasia and adamantinoma: A summary of diagnostic challenges and surgical techniques

Osteofibrous dysplasia is an indolent benign fibro-osseous tumor, while adamantinoma is a locally aggressive biphasic malignancy with epithelial and fibro-osseous components. Predominantly arising in the tibial diaphysis of children and young adults, both tumors are resistant to chemotherapy and radiation. Wide surgical resection is regarded as the mainstay of therapy for adamantinoma, and limb-salvage reconstructive procedures can achieve good functional outcomes, albeit with non-negligible rates of complications. This review discusses emerging advances in the pathogenesis, histogenesis, and diagnosis of these entities and presents advantages and limitations of the most common surgical techniques used for their management.

Osteofibrous dysplasia-like adamantinoma versus osteofibrous dysplasia in children: A case report of challenging diagnosis

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Challenging diagnostic regarding diagnosis of Osteofibrous dysplasia and Osteofibrous dysplasia-like adamantinoma.

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There is controversy spectrum disease between adamantinoma and OFD-like adamantinoma and OFD in children.

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Histopathology and immunohistochemical staining for diagnostic OFD, OFD-like adamantinoma and adamantinoma.

Introduction

Osteofibrous dysplasia (OFD) and Osteofibrous dysplasia-like Adamantinoma have a similar appearance both in clinical and radiography, but different in its histopathology. Despite this similarity, the treatment and prognosis are different, therefore the diagnosis should be established precisely.

Case illustration

A three-year-old boy was admitted to hospital after falling on his lower leg. A bead size lump appeared on his tibia with pain and swelling, which later became enlarged. Diagnosis of osteofibrous dysplasia and adamantinoma was considered. We performed limb-salvage procedure by curretage, bone grafting, and internal fixation application. The histology section showed woven bone rimmed by polygonal osteoblast cell with intervening fibrous stroma and small nests of tumour cells raised the possibility of epithelial differentiation. The positivity for cytokeratin immunostaining confirmed the diagnosis as osteofibrous dysplasia-like adamantinoma. In this case it is a very rare spectrum of malignancy in children.

Discussion

These two tumor entities have identical radiographic characteristics, histopathology features the distinction between classic adamantinoma and OFD-like adamantinoma based on the predominant epithelial component. The relationship of osteofibrous dysplasia with adamantinoma is unclear. Several authors considered possible calling relationship osteofibrous dysplasia as “juvenile adamantinoma”. However, does not rule out the possible existence of de novo osteofibrous dysplasia not related to adamantinoma.

Conclusions

OFD-like adamantinoma and Osteofibrous Dysplasia had similar histopathology pattern, a pathologist must be aware of this feature and perform immunohistochemical staining for keratin particularly when the histopathological feature of osteofibrous dysplasia showed small nests of tumor cells within the fibrous stroma. diagnostic challenging and require multidisciplinary approach.

Adamantinoma filling the medullary space of the tibia: A case report

Adamantinoma of the bone is a rare low-grade bony tumor that accounts for less than 1% of all primary bone tumors. On imaging, adamantinoma may be similar to other tumors such as osteofibrous dysplasia, for which the treatment protocol is completely different. Therefore, correct diagnosis and staging of adamantinoma ensures that the patient will undergo appropriate surgery. We present a case of atypical adamantinoma to highlight the fact that adamantinoma should be considered in the differential diagnosis of tibial tumors.

Cutaneous Basal Cell Carcinoma with Bone Metastases: An Orthopaedic Case Report

Basal cell carcinoma (BCC) is the most common skin cancer, and its incidence is increasing. Though metastatic BCC (mBCC) is uncommon, the literature demonstrates a 0.0028%-0.55% rate of metastasis. We report on a patient treated at our institution who was found to have mBCC with osseous metastases. To our knowledge, this is the first report of mBCC in the orthopaedic literature. Orthopaedic oncologists should consider mBCC in patients diagnosed with carcinoma of unknown origin, with a known history of BCC, or individuals with light skin pigmentation and age 50 or greater. This can help clinicians make the correct diagnosis and provide the appropriate treatment.

Extraperiosteal segmental excision for osteofibrous dysplasia of tibia with reconstruction by liquid nitrogen-treated recycled autograft

BACKGROUND

Osteofibrous dysplasia usually progresses until ten years of age and occasionally regresses spontaneously after puberty. Patients with osteofibrous dysplasia usually require close observation. Surgery is an option considered only for extensive, deforming lesions and those with pathological fractures and rapid progression prior to puberty. If surgery is indicated, the traditional intra-lesional curettage or subperiosteal resection usually leads to high recurrence. Hence, extraperiosteal wide excision and various methods of reconstruction after resection have been advocated for this lesion. We reviewed the clinical results of patients managed with extraperiosteal segmental excision and reconstruction by liquid nitrogen-treated tumor-bearing autograft combined with allograft.

METHODS

From January 2010 to December 2014, twelve patients with final diagnosis of tibial osteofibrous dysplasia were studied retrospectively. All these patients were treated with extraperiosteal segmental excision and reconstruction by liquid nitrogen-treated tumor-bearing autograft combined with allograft.

RESULTS

The patient group consisted of 5 males and 7 females, with a median age of 13 years (6-24 years). 3 lesions were located in left tibia and 9 in right. The median length of resected segment was 8 cm (5-11 cm). The patients were followed for 36-84 months (median 52 months). Follow-up radiographs showed that the median time for complete union of the grafted bone was 9 months (6-15 months). There was no evidence of recurrence. All patients had full range of motion in the knee and ankle joints after surgery.

CONCLUSIONS

Extraperiosteal segmental excision for osteofibrous dysplasia of tibia with reconstruction by liquid nitrogen-treated recycled autograft and allograft is a good surgical option to prevent recurrence and fill bone defects in this rare lesion.

TIBIAL ADAMANTINOMA: ANALYSIS OF SEVEN CONSECUTIVE CASES IN A SINGLE INSTITUTION

Objective:

Adamantinoma accounts for less than 1% of the primary bone neoplasms. The tibia is the most affected bone and it is predominant in male patients between the second and third decades of life. The objective of this study is to obtain epidemiological and clinical information on patients with adamantinoma of the tibia treated surgically between 1989 and 2016.

Methods:

Retrospective series of seven patients diagnosed with adamantinoma of the tibia that underwent surgery at the orthopedic oncology service of our hospital. The information was obtained from the medical records and histopathological reports of our institution.

Results:

A total of 2870 medical records with histological reports were evaluated. Seven cases of adamantinoma of the tibia were included. The mean age was 28.5 (17-49) years. We found a predominance of females (71.4%) and the most affected side was the left one, with four cases (57.1%). The biopsy revealed bone adamantinoma in four (57.1%) patients, while the diagnosis of the other patients was confirmed after the histological examination of the surgical specimen. All the patients underwent surgery as definitive treatment. No positive margins were reported. No local recurrence (LR) was reported and two patients had distant metastasis (DM).

Conclusion:

The prognosis of survival in cases of adamantinoma of the tibia is high. The rates of LR and DM were low. Surgical treatment with extensive tumor resection is the treatment of choice. Level of Evidence IV, Case Series.

Peering beneath the surface: Juxtacortical tumors of bone (part I)

Juxtacortical or surface tumors of bone are neoplasms arising from or just outside the cortex, and are composed of different histologic types. Although the imaging appearances of these lesions have similarities to their intramedullary counterparts, their location alters their radiographic and MR characteristics, creating difficulties in diagnosis. Meanwhile, several non-neoplastic lesions, such as stress reaction/stress fracture and indolent infectious processes, compound the differential diagnosis. Neoplastic juxtacortical lesions of bone have been classified into five categories: cartilaginous, fibrous, lipomatous, osseous, and metastatic tumors. Our goal in part one of this review is to illustrate the characteristic radiographic, CT and MR imaging features of various juxtacortical neoplasms, including pathognomonic imaging findings that can aid in diagnosis, and to develop an appropriate differential diagnosis for surface lesions based on imaging characteristics, lesion location and patient age.

Bilateral Tibial Osteofibrous Dysplasia on 18F-FDG PET/CT

A 17-year-old girl had pain in the right front lower leg while road racing 2 months earlier. Radiography and CT showed osteolytic lesions in the medial part of the bilateral tibia. Bone scintigraphy showed focally increased radiotracer uptake in the bilateral tibia. The lesions showed hypermetabolism on FDG PET/CT. Osteofibrous dysplasia was suspected from the radiographic findings, but adamantinoma or metastases could not be excluded. Surgical biopsies were performed, and histopathologic studies confirmed the diagnosis of bilateral osteofibrous dysplasia.

Angiomyolipoma of the rib: A rare case report

Angiomyolipoma is a benign mesenchymal tumor, most commonly arising from the kidney. With the exception of the liver, extrarenal angiomyolipoma is an infrequent entity that may be misdiagnosed as other tumors. Angiomyolipoma occurring in the skeleton is an extremely rare occurrence and often difficult to differentiate from other bone diseases. We herein present a case of angiomyolipoma in the rib of a 44-year-old male patient, a highly unusual location for this type of tumor. Angiomyolipoma of the skeleton usually exhibits an infiltrative tendency. Although this clinical entity is rare, angiomyolipoma should be considered in the differential diagnosis of skeletal lesions, particularly in patients presenting with imaging findings of fat within the lesions.

Surface primary bone tumors: Systematic approach and differential diagnosis

Surface primary bone tumors may appear similar to their intramedullary counterpart, but because they are rare, they may pose diagnostic challenges when showing different characteristics compared to their intramedullary counterpart. It is important for radiologists to recognize the imaging findings for various uncommon surface primary bone tumors, which may help to reduce the differential diagnosis or to lead to a specific diagnosis. Radiography is typically used for first-line imaging. If necessary, it is followed by CT or MRI for evaluation and characterization of surface bone tumors. The aim of this article is to review the imaging findings and differential diagnosis for surface primary bone tumors.