Does osteofibrous dysplasia progress to adamantinoma and how should they be treated?

Evaluation of subperiosteal hemicortical resection and bone grafting to treat tibial osteofibrous dysplasia in children

Osteofibrous dysplasia (OFD) is a rare disease that may lead to tibial lesions. Currently, no gold standard method exists for the treatment of OFD. Recurrence is the most severe complication in OFD. Autogenous iliac bone grafting may reduce postoperative recurrence rates in children with tibial OFD. We aimed to evaluate the clinical effects of subperiosteal hemicortical resection in patients with OFD. We included 21 patients who were diagnosed with OFD. Retrospective clinical data were analyzed from our hospital between November 2009 and October 2016. All the tibial lesions were removed with a subperiosteal hemicortical resection, and bone grafts were implanted. Patient age, sex, symptoms, lesion site, imaging, surgical methods, and histopathological data were analyzed. Local recurrence, postoperative recovery, and postoperative function were evaluated. The postoperative function was evaluated using the Musculoskeletal Tumor Society score (MSTS). OFD recurrence postsurgery occurred in eight patients; seven had no further recurrence after a second procedure, while one patient did not undergo another procedure. There were statistical differences in postoperative recurrence rates between the autogenous and other graft groups (P = 0.046). The median MSTS was 28 (27-30) and 30 (29.5-30) in the nonautologous (n = 15) and autologous graft groups (n = 6), respectively. The function of the nonautologous graft group was significantly worse than that of the autologous group (P = 0.029). We recommend that patients with tibial OFD undergo subperiosteal hemicortical resection plus autogenous iliac bone grafting. Our study findings showed that these patients experience reduced postoperative recurrence rates and improved prognostic function. Level of Evidence: IV.

Correction of anterior bowing complicating tibial osteofibrous dysplasia in preadolescents by osteotomy and telescopic nailing without lesional resection: a preliminary study of four-case reports

BACKGROUND

Osteofibrous dysplasia (OFD) occurs most frequently in the tibia and may result in deformity and pathological fracture. Surgical treatment such as curettage or segment excision has been performed but remains controversial due to high complication rates and surgical burden. This study introduces a new method to manage OFD with anterior bowing of the tibia using minimally invasive tibial osteotomy and telescopic rod (TR) osteosynthesis without extensive lesion resection.

METHODS

A retrospective study of 4 children with OFD and tibia bowing deformity treated with minimally invasive tibial wedge osteotomy and TR fixation between January 2015 and November 2020 was performed. Results including bone healing, complications, function based on MSTS score, and recurrance of deformity were assessed.

RESULTS

The median follow-up was 29 months. Radiographs showed the median time for union was 3 months. There were no instances of refracture or recurrence of deformity. The mean post-operative MSTS score was significantly higher than preoperative score.

CONCLUSIONS

This method avoids large bone defects and reconstructive procedures. It is an effective and minimally invasive approach for managing anterior bowing deformity secondary to OFD while improving function and quality of life.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

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.

Secondary osteosarcoma associated with osteofibrous dysplasia: a case report

Secondary osteosarcoma is a rare complication of primary malignancies and benign bone lesions. There are various types of diseases that cause secondary osteosarcoma. A 15-year-old male presented at our medical center complaining of pain and redness in the right lower leg. He had been diagnosed with osteofibrous dysplasia in the right tibia when he was 2 years old and since then had been followed up. Although he had a pathological fracture of the right tibia at the age of 7, his fracture healed with a plaster cast and did not require surgery. At the time of the patient's last visit, a radiograph revealed a periosteal reaction as well as erosion of the bone cortex. Magnetic resonance imaging revealed an infiltrative area in the soft tissue surrounding the osteofibrous dysplasia lesion in the tibia. Consequent to pathological examination (through bone biopsy), the patient was diagnosed with secondary osteosarcoma. The patient underwent chemotherapy and extensive resection with liquid nitrogen. He has been progressing satisfactorily after the operation. The present case is the first report of secondary osteosarcoma associated with osteofibrous dysplasia. During the long-term follow-up of osteofibrous dysplasia, oncologists should be aware of the possibility of secondary osteosarcoma.

Update of pediatric bone tumors-other mesenchymal tumors of bone, hematopoietic neoplasms of bone, and WHO classification of undifferentiated small round cell sarcomas of bone

There are numerous bone tumors in the pediatric population, with imaging playing an essential role in diagnosis and management. Our understanding of certain bone tumors has rapidly evolved over the past decade with advancements in next-generation genetic sequencing techniques. This increased level of understanding has altered the nomenclature, management approach, and prognosis of certain lesions. We provide a detailed update of bone tumors that occur in the pediatric population with emphasis on the recently released nomenclature provided in the 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumours. We discuss other mesenchymal tumors of bone, hematopoietic neoplasms of bone, and WHO classification of undifferentiated small round cell sarcomas of bone. We have detailed osteogenic tumors and osteoclastic giant cell-rich tumors, as well as notochordal tumors, chondrogenic tumors, and vascular tumors of the bone in separate manuscripts.

[Bone tumours-What's new in the 2020 WHO classification and beyond]

The recent WHO classification of Bone Tumours (2020) has introduced several changes. Conceptionally, small round cell sarcomas are now summarized in a distinct chapter, acknowledging their occurrence in both, bone and soft tissue. In the light of new molecular findings some diagnostic categories, such as fibrohistiocytic tumors, have been abandoned, and a few new entities have been added to the classification. Finally, systematic changes were made with regard to the terminology employed in the classification of chondrogenic tumours, and modifications have been made with respect to the biological potential of some lesions. This article summarizes the major changes made, underscoring the elementary role of an interdisciplinary approach in the diagnosis and management of bone lesions.

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.

Rapidly Progressive Classic Adamantinoma of the Spine: Case Report and Literature Review

Adamantinoma is a locally aggressive or malignant tumor, accounting for <0.5% of all primary bone tumors. The tumor usually progresses slowly, with a relatively promising prognosis. Primary or metastatic spinal adamantinoma of bone are rarer. Only four cases have been documented till date. We present two cases of aggressive spinal adamantinoma whose microphotography and radiographic appearance were unusual, with extensive involvement of multiple segments and rapid progression. Case 1 was a 36-year-old woman, presenting with back pain, progressive numbness and motor weakness, who was diagnosed with metastatic adamantinoma in the T2, T7, L2, and L4. She underwent spondylectomy three times to resect these lesions, respectively. Case 2 was a 68-year-old male with complaints of severe left back pain. MRI revealed destructive changes in T1-T4. He underwent posterior decompression (T1-T3), partial vertebrectomy (T2), fixation and fusion (C5-C7, T4-T6). The pathology of two patients was metastatic spinal adamantinoma, whose primary lesions were from tibia and femoral adamantinoma, respectively. Rapid squamous progression was observed in specimens of T2 and T7 lesions of Case 1 in two months. Twenty-five months after surgery, Case 1 developed paralysis, but she refused to receive further examination and treatment. Two months after surgery, Case 2 presented with an upper back pain again. The MRI revealed an increase in osseous destruction and paravertebral mass size. He was administered radiotherapy, with his upper back pain partially relieved. The biological behavior of classic adamantinoma is highly unpredictable, often exhibiting more aggressive behavior upon recurrence or metastasis. The pathological diagnosis of adamantinoma should be confirmed by preoperative biopsy. En bloc resection with a wide margin is the preferred treatment for primary spinal adamantinoma. Radiation therapy can partially relieve the pain.

Osteofibrous dysplasia of the tibia : the importance of deformity in surveillance

AIMS

Osteofibrous dysplasia (OFD) is a rare benign lesion predominantly affecting the tibia in children. Its potential link to adamantinoma has influenced management. This international case series reviews the presentation of OFD and management approaches to improve our understanding of OFD.

METHODS

A retrospective review at three paediatric tertiary centres identified 101 cases of tibial OFD in 99 patients. The clinical records, radiological images, and histology were analyzed.

RESULTS

Mean age at presentation was 13.5 years (SD 12.4), and mean follow-up was 5.65 years (SD 5.51). At latest review, 62 lesions (61.4%) were in skeletally mature patients. The most common site of the tibial lesion was the anterior (76 lesions, 75.2%) cortex (63 lesions, 62.4%) of the middle third (52 lesions, 51.5%). Pain, swelling, and fracture were common presentations. Overall, 41 lesions (40.6%) presented with radiological deformity (> 10°): apex anterior in 97.6%. A total of 41 lesions (40.6%) were treated conservatively. Anterior bowing < 10° at presentation was found to be related to successful conservative management of OFD (p = 0.013, multivariable logistic regression). Intralesional excision was performed in 43 lesions (42.6%) and a wide excision of the lesion in 19 (18.8%). A high complication rate and surgical burden was found in those that underwent a wide excision regardless of technique employed. There was progression/recurrence in nine lesions (8.9%) but statistical analysis found no predictive factors. No OFD lesion transformed to adamantinoma.

CONCLUSION

This study confirms OFD to be a benign bone condition with low rates of local progression and without malignant transformation. It is important to distinguish OFD from adamantinoma by a histological diagnosis. Focus should be on angular deformity, monitored with full-length tibial radiographs. Surgery is indicated in symptomatic patients and predicted by the severity of the initial angular deformity. Surgery should focus more on the deformity rather than the lesion. Cite this article: Bone Joint J 2022;104-B(2):302-308.

Osteofibrous Dysplasia and Adamantinoma

For decades, the diagnosis, treatment, and even pathogenesis of the osteofibrous dysplasia/osteofibrous dysplasia-like adamantinoma/classic adamantinoma spectrum of neoplasms have been controversial. Herein, we discuss and illustrate the radiographic and histologic spectrum, differential diagnoses, unifying chromosomal and molecular abnormalities, and current controversies and treatment recommendations for each entity.

Osteosarcoma arising in a case of osteofibrous dysplasia of tibia with classic adamantinoma: A case report and literature review

A five-year-old boy presented with left tibial swelling; there was a typical radiological feature of osteofibrous dysplasia. He was observed until the age of 14 years; there was development of aggressive radiological features. Biopsy revealed chondroblastic osteosarcoma. It was excised and the histology revealed chondroblastic osteosarcoma. A small lesion distal to the main tumour revealed adamantinoma within a background of feature of osteofibrous dysplasia. Proximally, feature of osteofibrous dysplasia was identified focally. The finding of adamantinoma over the distal part of the lesion supports that feature of osteofibrous dysplasia may be a precursor of adamantinoma. They may be a spectrum of diseases with multistep neoplastic transformation. The osteosarcoma may be a result of de-differentiation from adamantinoma. This case is remarkable as the patient was only 14 years old and the tumour showed typical features of osteosarcoma, with feature of osteofibrous dysplasia and adamantinoma found in the same specimen. Feature of osteofibrous dysplasia may be a precursor of adamantinoma, and adamantinoma may dedifferentiate into osteosarcoma.

Sclerotic bone lesions caused by non-infectious and non-neoplastic diseases: a review of the imaging and clinicopathologic findings

Bone sclerosis is a focal, multifocal, or diffuse increase in the density of the bone matrix on radiographs or computed tomography (CT) imaging. This radiological finding can be caused by a broad spectrum of diseases, such as congenital and developmental disorders, depositional disorders, and metabolic diseases. The differential diagnosis can be effectively narrowed by an astute radiologist in the light of the clinical picture and typical findings on imaging. Some of these lesions are rare and have been described as case reports and series in the literature. This article aims to collate the clinical-radiologic findings of non-infectious and non-neoplastic causes of bone sclerosis with relevant imaging illustrations.

Does the management of osteofibrous dysplasia of the tibia and fibula in children should be tailored to the extent and location of the lesion? A case control study investigating different surgical options

BACKGROUND

Osteofibrous dysplasia (OFD) is a rare non neoplastic, self-limited intracortical fibro-osseous lesion that most commonly affects the diaphysis of the tibia and fibula of children, the best treatment is still debated. Therefore we performed a retrospective study in children mostly under 10 years old with OFD aiming to determine whether early surgery is necessary and which is the best treatment.

HYPOTHESIS

Symptomatic OFD lesions should be treated proactively, and appropriate treatment can achieve favorable outcome.

METHODS

We retrospectively reviewed 23 patients with OFD of the tibia (n=22) and fibula. Management varied according to the severity of symptoms (deformity, pain or pathological fracture) and the extent of the lesion. Cases were divided into four groups (Gr.): Gr. 1: observation (n=4); Gr. 2: curettage and allograft (n=6); Gr. 3: curettage, allograft and elastic stable intramedullary nailing (ESIN) fixation (n=9); Gr. 4: extra-periosteal resection and bone transport (n=5). One patient received two different treatments successively (23 patients and 24 cases). All patients had regular clinical and radiographic follow-up to assess bone consolidation and complications.

RESULTS

In Gr. 1, four asymptomatic patients underwent observation after open biopsy. Gr. 4 had the lowest local recurrence rate: 0 cases (0%) vs. 4 (66.7%; Gr. 2) vs. 1 (11.1%; Gr. 3) (p=0.002), incidence of deformity: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 3 (50%; Gr. 3) (p=0.023), and pathological fracture: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 1 (16.7%; Gr. 3) (p=0.006), although the consolidation time was longer: 6.8 vs. 2 (Gr. 2) vs. 2.7 months (Gr. 3) (p=0.017) and the rate of complication was higher than those of Gr. 2 and Gr. 3 (p<0.05). Gr. 3 had a lower local recurrence rate: 1 case (11.1%) vs. 4 cases (66.7%) (p=0.002), incidence of deformity: 0 case (0%) vs. 3 cases (50%) (p=0.023), and pathological fracture: 0 case vs. 1 case (16.7%) (p=0.006) than Gr. 2.

DISCUSSION

Open biopsy is an important step in the management of patients with imaging suggestive of OFD in order to rule out Adamantinoma and other bone tumors or infection. Observation should be reserved for asymptomatic patients, while surgical treatment is indicated in patients with persistent pain, pathological fracture or significant deformity of the tibia. ESIN is a valid option to preserve the anatomical axis of the tibia in symptomatic patients with lesions of limited size; large circumferential lesions or recurrence can be managed by extra-periosteal resection and bone transport, although the complication rate can be relatively high.

LEVEL OF EVIDENCE

III; case control study.

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.

Updates from the 2020 World Health Organization Classification of Soft Tissue and Bone Tumours

The fifth edition of the World Health Organization (WHO) classification of soft tissue and bone tumours was published in May 2020. This 'Blue Book', which is also available digitally for the first time, incorporates an array of new information on these tumours, amassed in the 7 years since the previous edition. Major advances in molecular characterisation have driven further refinements in classification and the development of ancillary diagnostic tests, and have improved our understanding of disease pathogenesis. Several new entities are also included. This review summarises the main changes introduced in the 2020 WHO classification for each subcategory of soft tissue and bone tumours.

Recurrent adamantinoma of the mandible

Adamantinoma is an extremely rare tumour originating from bone that can be divided into classical and osteofibrous dysplasia (OFD)-like adamantinoma. This low-grade malignancy almost exclusively occurs in long bones, and only few cases of mandibular adamantinoma have been reported. Here, we report the case of a 30-year-old female with a 2-year history of right mandible tenderness. Radiological examinations showed a lytic lesion involving the right mandible without a well-defined margin. Biopsy confirmed the diagnosis of adamantinoma. She underwent a segmental mandibulectomy and reconstruction with a fibula flap. The definitive diagnosis was OFD-like adamantinoma. However, the tumour recurred after 5 years. The residual mandible and fibula flap were widely involved. A total mandibulectomy was performed. Five years later, there is no evidence of recurrence or metastasis. We recommend that adamantinoma be treated by radical resection with clear margins, and long-term surveillance is necessary due to the likely high local recurrence rate and the potential for late tumour metastasis.

Surgical Outcome and Oncological Survival of Osteofibrous Dysplasia-Like and Classic Adamantinomas: An International Multicenter Study of 318 Cases

BACKGROUND

Osteofibrous dysplasia-like adamantinoma (OFD-AD) and classic adamantinoma (AD) are rare, neoplastic diseases with only limited data supporting current treatment protocols. We believe that our retrospective multicenter cohort study is the largest analysis of patients with adamantinoma to date. The primary purpose of this study was to describe the disease characteristics and evaluate the oncological outcomes. The secondary purpose was to identify risk factors for local recurrence after surgical treatment and propose treatment guidelines.

METHODS

Three hundred and eighteen confirmed cases of OFD-AD and AD for which primary treatment was carried out between 1985 and 2015 were submitted by 22 tertiary bone tumor centers. Proposed clinical risk factors for local recurrence such as size, type, and margins were analyzed using univariable and multivariate Cox regression analysis.

RESULTS

Of the 318 cases, 128 were OFD-AD and 190 were AD. The mean age at diagnosis was 17 years (median, 14.5 years) for OFD-AD and 32 years (median, 28 years) for AD; 53% of the patients were female. The mean tumor size in the OFD-AD and AD groups combined was 7.8 cm, measured histologically. Sixteen percent of the patients sustained a pathological fracture prior to treatment. Local recurrence was recorded in 22% of the OFD-AD cases and 24% of the AD cases. None of the recurrences in the OFD-AD group progressed to AD. Metastatic disease was found in 18% of the AD cases and fatal disease, in 11% of the AD cases. No metastatic or fatal disease was reported in the OFD-AD group. Multivariate Cox regression analysis demonstrated that uncontaminated resection margins (hazard ratio [HR] = 0.164, 95% confidence interval [CI] = 0.092 to 0.290, p < 0.001), pathological fracture (HR = 1.968, 95% CI = 1.076 to 3.600, p = 0.028), and sex (female versus male: HR = 0.535, 95% CI = 0.300 to 0.952, p = 0.033) impacted the risk of local recurrence.

CONCLUSIONS

OFD-AD and AD are parts of a disease spectrum but should be regarded as different entities. Our results support reclassification of OFD-AD into the intermediate locally aggressive category, based on the local recurrence rate of 22% and absence of metastases. In our study, metastatic disease was restricted to the AD group (an 18% rate). We advocate wide resection with uncontaminated margins including bone and involved periosteum for both OFD-AD and AD.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

[Tumor-like bony lesions of the skeleton]

Tumor-like bony lesions are, by definition bony lesions, which can be clinically, radiologically and histologically mistaken for real bone tumors. This article presents the aneurysmal bone cyst (ABC), solitary bone cyst (SBC), fibrous dysplasia, osteofibrous dysplasia Campanacci and non-ossifying fibroma (NOF). Many tumor-like bony lesions are often incidental findings. The combination of X‑ray imaging specifically supplemented by magnetic resonance imaging (MRI) or computed tomography (CT) enables a diagnostic classification in the majority of cases.

Osteofibrous dysplasia-like adamantinoma treated via intercalary segmental resection with partial cortex preservation using pedicled vascularized fibula graft: a case report

Background

Morphologically, osteofibrous dysplasia-like adamantinoma is thought to be intermediate between osteofibrous dysplasia and adamantinoma. Its treatment is not well established owing to its rarity.

Case presentation

We report about of a 10-year-old girl with osteofibrous dysplasia-like adamantinoma initially diagnosed as osteofibrous dysplasia and treated via intercalary segmental resection with partial cortex preservation using a pedicled vascularized fibula graft for reconstruction. Bone union was observed 9 weeks after surgery. Twenty-two months after the definitive surgery, no recurrence was observed.

Conclusion

This case illustrates the upgrade from osteofibrous dysplasia to osteofibrous dysplasia-like adamantinoma. The surgical method may aid the treatment of osteofibrous dysplasia-like adamantinoma with incomplete cortex involvement of the tumor.

Adamantinoma of Pelvis: A Rare Tumor at an Uncommon Site, with Diagnostic Implications

Adamantinoma is a low-grade malignant bone tumor with metastatic potential in the range of 15-20%, commonly affecting mid-diaphyseal tibial region and jaw. Numerous cases of adamantinoma affecting the appendicular skeleton have been reported but only three in the pelvis till date. We present the case of a 24-year-old male, who was initially reported as fibrous dysplasia for a lesion in pelvis. On review, a cellular tumor was noted, including areas resembling fibrous dysplasia, along with cords and nests of polygonal cells, which displayed positive immunoexpression with cytokeratin and p40. Subsequently, he underwent wide local resection (internal hemipelvectomy), along with mesh pseudoarthrosis was done. Diagnosis of adamantinoma was further confirmed, with clear resection margins. Currently, the patient is on a regular clinical and radiological follow-up. Careful assessment of key histomorphologic features, coupled with immunohistochemical stains and clinico-radiological correlation, is helpful in identifying this uncommon tumor at a rather rare site.

Outcome of osteofibrous dysplasia-like versus classic adamantinoma of long bones: a single-institution experience

Background

The clinical and molecular characteristics of osteofibrous dysplasia (OFD)-like adamantinoma (AD) differ from those of classic AD. Most reports about OFD-like AD are case reports or small case series. More cases from different centers are still warranted.

Methods

The orthopedic oncology database of our institution was searched to identify patients with AD. The cases of OFD-like and classic AD of the long bones were retrospectively analyzed. Between December 1999 and August 2016, 23 patients were treated for AD, comprising seven with OFD-like AD and 16 with classic AD. The outcomes were compared between AD subtypes.

Results

In the OFD-like AD group, four lesions were treated with extensive curettage, while three were treated with wide resection. The median follow-up duration in the OFD-like AD group was 66 months (range 43–131 months). At the end of follow-up, there was only one case of local recurrence (LR) in the OFD-like AD group, giving a LR rate of 14.3% (1/7). No distant metastasis or progression to classic AD was detected in the OFD-like AD group. In the classic AD group, the treatments were below-the-knee amputation in one patient with extensive tibial and fibular lesions, curettage with a bone graft in one patient who was diagnosed with OFD based on a core needle biopsy, hemi-cortical excision and reconstruction in two patients, and segmental resection and reconstruction in 12 patients. At the end of follow-up, there were three cases of LR in the classic AD group, giving a LR rate of 18.8% (3/16); two patients developed lung metastasis after LR and died of the disease at 88 and 126 months after the first surgery in our hospital, respectively. The classic AD group had a metastatic rate of 12.5% (2/16), a final limb salvage rate of 75%, and estimated 5- and 10-year survival rates of 88.9% and 77.1%, respectively.

Conclusions

OFD-like AD has a better outcome than classic AD. For OFD-like AD, extensive curettage is suggested if the tumor extent allows. For classic AD, aggressive resection with wide margins is essential to achieve local control. A long-term follow-up is necessary due to the possibility of late complications.

[Tumor-like bony lesions of the skeleton]

Tumor-like bony lesions are, by definition bony lesions, which can be clinically, radiologically and histologically mistaken for real bone tumors. This article presents the aneurysmal bone cyst (ABC), solitary bone cyst (SBC), fibrous dysplasia, osteofibrous dysplasia Campanacci and non-ossifying fibroma (NOF). Many tumor-like bony lesions are often incidental findings. The combination of X‑ray imaging specifically supplemented by magnetic resonance imaging (MRI) or computed tomography (CT) enables a diagnostic classification in the majority of cases.

Epidemiological Study of Adamantinoma from US Surveillance, Epidemiology, and End Results Program: III Retrospective Analysis

Objective

Adamantinomas are rare low-grade malignant bone tumors. This study aims to describe the demographic characteristics and survival rates of patients suffering from adamantinomas.

Methods

The National Institute of Cancer Surveillance, Epidemiology, and Recent Results (SEER) database was used, and patients diagnosed with adamantinoma between 1973 and 2016 were screened. Patients were classified according to sex, age, race/ethnicity, and marital status, and also tumors were classified according to year of diagnosis, laterality, type of treatment, and follow-up.

Results

The mean age of patients was 30.8 ± 16.7 (range: 4–75). A total of 92 patients were identified; of these, 43 were females and 49 were males. The mean follow-up period was 138.1 ± 90.3 (range: 1–156) months. Mean survival duration was 287.8 ± 15.4 (95% CI: 257.7–317.9) months. Five- and ten-year survival rates were 98.8% and 91.5%, respectively. Besides, survival time was also observed to be independent of gender, age groups, race, marital status, tumor location, and year of diagnosis.

Conclusion

Adamantinoma is a very rare bone tumor that affects the long bones in lower extremities and is more common in men. Five- and 10-year survival prognoses are reasonably satisfactory. Also, survival time is independent of variables such as gender, age, and tumor location.

Adamantinomatous tumors: Long-term follow-up study of 20 patients treated at a single institution

BACKGROUND AND OBJECTIVES

Adamantinomas are primary, low-grade malignant tumors of the bone that have metastatic potential to the lungs, lymph nodes, and other regions. The rarity of this disease and its nonspecific symptoms complicate diagnosis.

MATERIALS AND METHODS

Records for 20 patients who underwent treatment for adamantinoma from 1975 to 2018 were reviewed for demographic, clinical, and pathological data, treatment details, postoperative complications, and outcomes.

RESULTS

Patients presented at a median age of 22 years (1-79 years): 14 patients had a localized primary tumor, three presented with local recurrence, and three with metastatic disease. Median tumor size was 5.7 cm (0.5-15.5 cm). Wide excision was performed primarily in 15 cases; the remaining five patients underwent intralesional curettage. At a median follow-up of 7.3 years, 14 patients had no evidence of disease; two patients were alive with disease, and four patients died from the disease. Local recurrence and distant metastasis occurred at a median of 11.4 years (6 month-19 years) and 15.8 years (4 month-23 years) after diagnosis.

CONCLUSIONS

Adequate histopathological diagnosis is crucial to avoid misdiagnosis of this rare tumor. Local and distant recuAbs_Para_meprrence can occur more than 20 years after the initial diagnosis. Life-long follow-up with clinical examination and imaging is required.

Osteofibrous Dysplasia of the Tibia in Children: Outcome Without Resection

BACKGROUND

The proposed association between osteofibrous dysplasia and adamantinoma has led some to advocate resection of the entire lesion, which can require major subsequent reconstruction. However, this link remains unproven and there is some support in more recent literature for a less aggressive approach. This study aims to describe our experience managing pediatric tibial osteofibrous dysplasia with such an approach and to report functional outcomes in children treated thus.

METHODS

A total of 28 cases of osteofibrous dysplasia in 25 patients were managed at a referral center for pediatric bone tumors with observation in the first instance, then limited surgical intervention if required to address pain and deformity. Surgery aimed to restore stability and alignment without excising the lesion. Clinical records provided basic clinical outcome measures involving walking, recreation, orthoses and school/work participation and patients provided a Musculoskeletal Tumour Society score (MSTS) where contactable.

RESULTS

Mean age at presentation was 6.0 years and mean follow-up was 8.3 years. Only 8 patients required surgery. According to basic outcome measures, 13 patients were symptom-free. About 15 patients (17 cases) provided a MSTS and the mean score was 24 of 30. No transformation to adamantinoma was observed. Those who presented at a younger age and with bilateral disease more often required surgery and remained symptomatic.

CONCLUSIONS

A less aggressive approach to pediatric tibial osteofibrous dysplasia achieves good functional outcomes and patient satisfaction in most cases. Surgery is required in the minority of cases. Transformation to adamantinoma was not observed in this series. We recommend patient education, clinical observation and reactive intervention if required, rather than proactive resection and reconstruction.

LEVEL OF EVIDENCE

Level IV-case series.

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.