Clinical outcomes in patients with adamantinoma: Report from the bone and soft tissue tumor registry in Japan

BACKGROUND

Adamantinomas are rare malignant bone tumors. Due to their low incidence, there are few reports on the clinical results of adamantinoma.

OBJECTIVES

This study aims to clarify outcomes in patients with adamantinoma using data from the National Bone and Soft Tissue Tumor Registry.

METHODS

From 2006 to 2019, 38 cases of tibial origin were included. Twenty-four were male and 14 were female, with a mean age of 37 (6-87) years and a mean follow-up of 35 (1-128) months.

RESULTS

Surgery was performed in 33 cases (87%) (curettage: 4 cases, wide resection: 27 cases, amputation: 2 cases). Reconstruction was performed in 27 patients who underwent wide resection. A total of 12 additional surgeries were performed in 11 patients. The main reason for the additional surgeries was nonunion of grafting bone in 6 cases. Oncologic outcomes were DOC (death from other causes) in one case and NED (no evidence of disease) in 37 cases.

CONCLUSIONS

The results of treatment of adamantinomas in Japan have been extremely favorable. This may be due in part to the large number of cases with wide resection.

Rare Case of Recurrent Adamantinoma of the Tibia: Limited Efficacy of Pazopanib as a Standalone Treatment

BACKGROUND Adamantinoma is a rare low-grade malignant bone tumor, usually found in the tibial diaphysis and metaphysis, with histological similarities to mandibular ameloblastoma. The most effective treatment of recurrent adamantinoma is not yet clear. This report is of a 22-year-old woman with recurrent tibial adamantinoma treated with the tyrosine kinase inhibitor pazopanib. CASE REPORT We report the case of a 22-year-old woman who was referred to our center for a suspicious bone lesion in the right tibia. Bone biopsy findings were consistent with an adamantinoma. En bloc resection was completed successfully, with no postoperative complications. Five years later, a positive emission tomography scan revealed mildly increased tracer uptake near the area of the previous lesion and in the right inguinal lymph node. Biopsies of the lesion and inguinal lymph node confirmed recurrence of the adamantinoma. Due to abdominal and pelvic metastasis, the patient underwent surgical debulking, along with an appendectomy, right salpingo-oophorectomy, intraoperative radiation therapy, and hyperthermic intraperitoneal chemotherapy. Subsequently, the patient was placed on pazopanib for 4 months; however, her tumor continued to worsen after 4 months of chemotherapy. Currently, the patient is receiving gemcitabine and docetaxel as second-line medical therapy. CONCLUSIONS This report showed that pazopanib as standalone treatment does not appear to have promising role on patient outcomes. To the best of our knowledge, this is the second report of pazopanib in the treatment of adamantinoma.

Adamantinoma of the Ulnar Shaft Reconstructed With a Vascularized Free Fibula

We describe a 36-year-old man with a long-standing diagnosis of ulnar fibrous dysplasia with associated fracture of the ulna. He presented with a growing and increasingly tender forearm mass and was diagnosed with adamantinoma of the ulna, for which he underwent wide resection of the ulnar diaphysis followed by reconstruction with a vascularized fibula autograft. This case serves to emphasize the importance of performing a stepwise workup for the diagnosis of osseous neoplasms even in cases with long-standing diagnoses. [Orthopedics. 2024;47(2):e102-e105.].

Adamantinoma-Like Ewing Sarcoma Mimicking Merkel Cell Carcinoma in the Parotid Gland: A Diagnostic Pitfall

Adamantinoma-like Ewing sarcoma (ALES) is a newly described rare entity, which shows EWSR1::FLI1 rearrangement characteristic of Ewing sarcoma. This can be diagnostically challenging as it manifests histologically with epithelial differentiation and has diffuse keratin expression as well as p40 and p60 positivity. We hereby report a case of ALES in a 33-year-old woman with a past medical history of breast carcinoma who presented with a right-sided parotid mass. CT scan of the neck showed a heterogenous mass within the superficial lobe, measuring 17 mm in diameter for which the patient underwent superficial parotidectomy. Histopathology of the mass revealed a malignant neoplasm formed of solid nests, cords and sheets of cells with minimal cytoplasm and monomorphic nuclei with granular chromatin and indistinct nucleoli. Brisk mitotic activity and tumor necrosis were also present. The tumor showed strong and diffuse reactivity for pankeratin (clone AE1/AE3) and keratin 20, both in a dot-like pattern, raising the suspicion of metastatic Merkel cell carcinoma; however, molecular studies showed EWSR1::FLI1 rearrangement, supporting the diagnosis of ALES. In summary, it is prudent to have knowledge about this entity to avoid its misdiagnosis as other malignancies of the head and neck region which exhibit a different clinical course, prognosis and hence treatment modalities.

Understanding The Rare Bone Tumor "ADAMANTINOMA"

Adamantinoma is a rare neoplastic bone tumor that has the potential to metastasize. The classic presentation is in the tibial region however; cases involving other bones of the body have been noticed. The tumour is very likely to be mistaken for other bone diseases and therefore it is important to investigate and study about its nature and thus differentiate it from other differentials. Nevertheless, literature on the presentation, findings, investigations and treatment options of adamantinomas are limited. In this case series, we report four cases from a local hospital in Karachi who were diagnosed, treated and followed up for adamantinoma. Studies regarding the disease will help us understand more about its features.

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.

Adamantinoma: metastatic disease masquerading as a gynaecological malignancy

Adamantinoma is a rare low-grade malignancy of the appendicular skeleton with unclear histogenesis. We present the case of a 65-year-old woman with known recurrent and metastatic right tibial disease despite clear resection margins. On further investigation, a positron emission tomography-CT scan identified a primary breast lesion and an 11 cm mass in the right iliac fossa of suspected ovarian malignancy amenable to surgical resection. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy and resection of a retroperitoneal mass arising from the pelvic sidewall encompassing the iliac vasculature. The patient made an uneventful recovery with histology confirming disease metastasising to the pelvis. Currently, clinical management guidelines are not available. We present an overview of adamantinoma and highlight a previously undocumented gynaecological oncology surgical approach to this novel disease location. Regarding metastases, we acknowledge the challenges of investigation pertaining to disease site and origin as well as a paucity of recommendations for surveillance and follow-up.

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.

Microsurgical reconstruction with vascularized fibula and massive bone allograft for bone tumors

INTRODUCTION

Combining massive bone allograft and vascularized fibula in intercalary reconstruction following resection of bone tumors represents a complex reconstructive procedure that requires specialists in microvascular surgery as well as orthopedic surgery. The purpose of our study was to examine the outcomes using this surgical technique in patients with bone tumors in terms of oncologic results, complications related to surgery, Musculoskeletal Tumor Society (MSTS) scores and duration of surgery.

MATERIALS AND METHODS

We analyzed 81 patients with femoral or tibial sarcomas who underwent intercalary resection and microsurgical reconstruction with massive bone allograft and vascularized fibula. There were 56 boys and 25 girls with a mean age of 13.4 years at the time of surgery. The patients' medical records were reviewed for clinical and functional outcomes as well as postoperative complications. The study group was comprised of 33 patients who underwent reconstruction of the femur with massive bone allograft and free vascularized fibula and 48 patients who underwent reconstruction of the tibia with massive bone allograft and free or pedicle vascularized fibula. The mean length of resection was 15.9 cm (8-31 cm). The functional evaluation of the patients was done at the end of the follow-up using MSTS score for the lower limb. All patients had at least a 2-year follow-up.

RESULTS

The overall limb salvage rate was 94%, although many patients required re-operation after the procedure. Complications occurred in 24 patients, 18 of which underwent additional surgical procedures. They included fractures of the massive bone allograft-vascularized fibula construct with or without implant failure (19) and deep infection (5). After surgical or conservative treatment, all the fractures successfully healed. The overall MSTS functional score was good to excellent in 91% of patients.

CONCLUSIONS

The combination of massive bone allograft and vascularized fibula seems to be a reasonable option for reconstruction of diaphyseal defects following intercalary resection of bone tumors. Although there was a high rate of complications and therefore re-operations, the biology of vascularized fibula was able to save the reconstruction in most of the cases that had complications.

[A Case of Liver and Pulmonary Metastases from Adamantinoma, a Bone Tumor]

This case involved a 28-year-old man who had undergone surgery and perioperative chemotherapy for an adamantinoma of the right tibia with multiple lung metastases. Sixteen months after the initial diagnosis, CT revealed an 8 cm diameter liver metastasis and right pneumothorax with little change in the lung metastases. Liver resection and partial pneumonectomy were performed. Pathologic findings confirmed that both liver and lung specimens had metastases from the adamantinoma. Dissimilar from the primary lesion with much interstitial tissue and spindle-shaped cells, the liver metastasis had very dense cell proliferation without interstitial tissue and dominant epithelial parts, suggesting a higher malignant potential. If other lesions are under good control, resection of the newly appearing metastasis, which has a higher malignant potential, might improve prognosis. Further accumulation of cases and detailed studies is required.

Adamantinoma

A 73-year-old woman with no significant past medical history presents with a palpable lump in the midshaft of the left tibia and intermittent mild discomfort for the past 8 months.

Adamantinoma of tibia in Ethiopia: the first bone transplant in Ethiopia

Adamantinoma of long bones is an extremely rare tumor with no report, to authors' knowledge from neither Ethiopia nor Africa. We are reporting a 25 year old female college student with one and half years history of right mid leg pain and swelling with radiologically and histologically proven adamantinoma of right tibia. At CURE Hospital, she had undergone complete excision of the tumor with histologically documented clean margins. The limb was salvaged by reconstructing with a fresh frozen tibial allograft obtained from the USA and an interlocking intramedullary nail (SIGN nail). Such insertion and incorporation of huge allograft using SIGN nail and saving a limb is the first surgery in Ethiopia. The gradual incorporation of the allograft at different months during follow-up is elucidated with clinical signs of healing.

CONCLUSION

At times, limb salvage surgery and technology should be offered to selected patients with a chosen type of bone tumor.

Adamantinoma of the tibia with late skeletal metastasis: an unusual presentation

Adamantinoma is a rare tumour of long bones that occurs most commonly in the tibia. Its pathogenesis is unknown. It is locally aggressive and recurrences are common after resection. Metastases have been reported in 10% to 20% of cases, most commonly in the lungs and rarely in the lymph nodes. We report a patient who developed a skeletal metastasis four years after resection of the primary tumour. There was no evidence of recurrence at the primary site or of secondary deposits in the lungs.

Treatment of osteofibrous dysplasia and associated lesions

PURPOSE

To report long term treatment outcomes of osteofibrous dysplasia and association with adamantinoma.

PATIENTS AND METHODS

From January 1984 to July 2001, 14 patients with osteofibrous dysplasia were followed for an average of 108 months (78 to 260 months). Our patient group consisted of 6 men and 8 women, with a mean age of 13.9 years (2 to 65 years). We reviewed the clinical and pathological features of all 14 patients.

RESULTS

Thirteen patients had a lesion in the tibia, while one patient had lesions in both the tibia and the fibula. Initial treatments were observation after biopsy (6 patients), curettage with or without a bone graft (3 patients), resection followed by a free vascularized fibular bone graft (4 patients), or resection and regeneration with the Ilizarov external fixation (1 patient). Curettage was performed on 6 patients due to recurrence or progression after the initial treatment. Among these patients, one was diagnosed with AD from the biopsy of the recurrent lesion. This patient was further treated by segmental resection and pasteurization. After the initial pathology slides of the 13 patients were reviewed with immunohistochemical cytokeratin staining, one patient diagnosis was changed from osteofibrous dysplasia to osteofibrous dysplasia-like adamantinoma.

CONCLUSION

Some patients with osteofibrous dysplasia require close observation because of the high association risk between osteofibrous dysplasia and adamantinoma, Immunohistochemical staining may be helpful in differentiating these two diagnoses.

Adamantinoma in childhood: report of six cases and review of the literature

BACKGROUND

Adamantinoma is a rare slow-growing malignant bone tumour.

OBJECTIVE

To describe the imaging appearances of six childhood cases and review the published literature.

MATERIALS AND METHODS

The database of the Working Group on Paediatric Oncology, Academic Medical Centre/Emma Children's Hospital Amsterdam, was searched for cases of adamantinoma. Additionally a literature study was performed to identify cases of adamantinoma in childhood.

RESULTS

We identified six local cases of adamantinoma of the long bones, two boys (age 3 and 8 years) and four girls (mean age 8.8 years, range 3.0-14.0 years). The location of the tumour was the tibia in five and the tibia and fibula in one patient. In two patients initially a different diagnosis was made, which led to a delay in appropriate treatment. None of the children showed pulmonary metastases and all underwent total gross resection. On follow-up (mean 6.1 years, range 1.6-12.0 years) all children remained disease-free. Besides a discussion of our six patients, imaging features, histopathology, surgical approach and a literature review of childhood adamantinomas is presented.

CONCLUSION

Although the incidence of adamantinoma is low, it is important to recognize this rare bone tumour, since in the early stages of the disease adequate treatment will result in an excellent prognosis.

Adamantinoma of the spine: case report

OBJECTIVE

We report a patient with a cervicothoracic spinal and a mandibular adamantinoma. Adamantinoma is a rare malignant neoplasm of bone and, to our knowledge, there have been only five cases of spinal adamantinoma reported. The pathogenesis of the adamantinoma, as well as the management of this extremely rare spinal tumor, is reviewed.

CLINICAL PRESENTATION

A 55-year-old man was admitted to our service with cervical pain and signs of C8 and T1 radiculopathy. On physical examination, cervical spine deformity, swelling in the left mandible region, and signs of C8 and T1 radiculopathy were observed. Neuroradiology examinations showed an osteolytic mass of the C6, C7, and T1 vertebral bodies, extending into the lateral masses and transverse processes. After surgical procedures, the patient had clinical improvement.

INTERVENTION

Corpectomy of C6, C7, and T1 was performed through a cervicothoracic anterior approach. Anterior stabilization of the spine was obtained using an autologous iliac crest graft and osteosynthesis with an anterior plate. On a second procedure, posterior tumor resection and spinal stabilization were performed. After the 1-year follow-up examination, a new anterior procedure was performed because of tumor recidivity and spine instability.

CONCLUSION

Adamantinoma, an extremely rare lesion, is a locally aggressive tumor with slow growth and the potential to metastasize. Although it is an extremely rare occurrence in the spine, adamantinoma should be considered on the diagnosis of tumors of the vertebrae. Neuroradiological examinations are not specific in the differentiation of this tumor from other conditions. This fact, coupled with the limited experience that most physicians in general have in dealing with this tumor, makes the diagnosis and treatment of adamantinoma challenging.

Fibular osteoadiposal flap for treatment of tibial adamantinoma: a case report

We treated a case with left tibial adamantinoma by use of a contralateral fibular osteoadiposal flap. The donor site of conventional fibular osteocutaneous flap must be covered with a skin graft because if we close the donor skin defect directly, compartment syndrome might occur. We were able to close the donor skin defect because this combined type flap included only a small monitoring skin paddle. We present herein the utility of the osteoadiposal flap and show the value of a skin-sparing approach with a minimal aesthetic defect.

Tibial adamantinoma with local recurrence and pulmonary metastasis: report of a case with histocytologic findings

BACKGROUND

Adamantinoma is a rare primary bone neoplasm of low malignant potential that may recur or metastasize in a mall percentage of patients. The myriad histologic patterns may cause difficulty in distinguishing this tumor from other primary or metastatic neoplasms. The cytomorphologic findings of fine needle aspiration biopsy were reported previously in only a small number of cases.

CASE

A 32-year-old man presented with a mass in the distal side of the left leg that was diagnosed as classic adamantinoma by open biopsy. Local recurrence and pulmonary metastases were confirmed by fine needle aspiration biopsy, which showed low grade, uniform cells with nuclear membrane grooves. The patient underwent a below-the-knee amputation and is receiving palliative treatment for progressive pulmonary spread.

CONCLUSION

The diagnosis of adamantinoma requires knowledge of compatible clinical and radiologic studies as well as understanding of the variable histologic patterns that one may encounter. Fine needle aspiration biopsy is particularly useful in the diagnosis of recurrent and metastatic adamantinoma. This case report describes a distinctive cytomorphologic feature of nuclear grooves that may be a useful aid in distinguishing the tumor cells of adamantinoma from other cell types.

Classical and atypical location of adamantinomas--presentation of two cases

BACKGROUND

Adamantinomas are rare low-grade primary bone tumors of unknown histological origin. They typically develop in the diaphyses and metaphyses of long bones, prevalently the tibia.

CASE REPORTS

The cases of 2 female patients, one with localized swelling of the lateral metatarsals and one with pain of the tibia are being reported. The diagnostic work-up including biopsy verified an adamantinoma in both cases. In the younger patient, the tumor was located in the metatarsals 4 and 5, in the older patient in the left tibial diaphyses. In both patients, an en-bloc resection of the tumor with wide surgical margins was performed. Further follow-ups 73 and 36 months after surgery showed no local recurrence or metastatic spread.

CONCLUSION

Adamantinomas of the short bones are rarely reported. In accordance to the literature, an en-bloc resection with wide surgical margins seems to reduce the risk of local recurrence and metastatic spread.

Osteofibrous dysplasia of the tibia

Osteofibrous dysplasia is an unusual developmental condition of childhood, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial and some authors believe that they are part of one histological process.

We retrospectively reviewed 16 patients who were diagnosed as having osteofibrous dysplasia initially or on the final histological examination. Their management was diverse, depending on the severity of symptoms and the extent of the lesion. Definitive (extraperiosteal) surgery was localised ‘shark-bite’ excision for small lesions in five patients. Extensive lesions were treated by segmental excision and fibular autograft in six patients, external fixation and bone transport in four and proximal tibial replacement in one. One patient who had a fibular autograft required further excision and bone transport for recurrence. Six initially underwent curettage and all had recurrence. There were no recurrences after localised extraperiosteal excision or bone transport. There were three confirmed cases of adamantinoma.

The relevant literature is reviewed. We recommend extraperiosteal excision in all cases of osteofibrous dysplasia, with segmental excision and reconstruction in more extensive lesions.

Synchronous intracortical adamantinomas with keratin cyst formation

Adamantinoma of the long bones is a rare primary bone tumor of uncertain embryogenesis. It tends to involve the tibia almost exclusively. We report on adamantinomas occurring in a 16-year-old male patient, with synchronous tibial and fibular lesions. Histologically, there were characteristic clusters of epithelial cells in a fibrous background, forming a keratin cyst. Immunohistochemically, these cells were strongly positive for cytokeratin. This keratin cyst formation is quite an unusual finding in classic adamantinoma.

Case report: metastatic adamantinoma of the tibia--an unusual presentation

A 26-year-old female with a tibial lesion diagnosed as an adamantinoma was treated with intra-lesional curettage, bone grafting and intra-medullary nailing. Six years post-surgery, she presented with an asymptomatic primary site but with a metastatic lesion in the mid-shaft of the ipsilateral femur and lung metastases. The femoral lesion was treated with wide excision and reconstructed with an allograft and plate fixation. Pulmonary metastatectomy was carried out for the lung lesions. A follow-up CT scan of the chest at 1 year after the surgery for the metastatic lesions revealed fresh unresectable bilateral metastases. Although cases of local recurrences and pulmonary metastases in adamantinoma are reported, this case is unusual in presenting without a local recurrence but with simultaneous skeletal and pulmonary metastases.

Adamantinoma of tibia: A study of 12 cases

BACKGROUND

Adamantinoma is a rare tumor of long bones that can be mistaken for a carcinoma, and numerous other lesions such as myoepithelial tumor, malignant mixed tumor of bone, fibrous dysplasia/osteofibrous dysplasia, and vascular tumors.

METHODS

The histology and clinical features of 12 cases accrued from the surgical pathology files over a period of 23 years were analyzed.

RESULTS

Of the 12 cases, 4 were men and 8 women, with a mean age of 30 years. Radiologically the tumor presented as a lytic, eccentric, intracortical lesion in the tibia. The histology revealed epithelial islands with basaloid, spindle, and squamous features on a background of fibrotic stroma. Three patients came back with local recurrences, and one of them developed pulmonary metastasis.

DISCUSSION

In this article, an attempt is made to study the morphology, biology, and the differential diagnoses of adamantinoma of long bones.

Allograft reconstruction for bone sarcoma of the tibia in the growing child

The outcome of tibial allograft reconstruction after resection of a tumour is inconsistent and has a high rate of failure. There are few reports on the use of tibial allografts in children with open growth plates. We performed 21 allograft reconstructions (16 osteoarticular, five intercalary) in 19 consecutive patients between seven and 17 years of age. Two had Ewing’s sarcoma, one an adamantinoma and 16 osteosarcoma, one with multifocal disease.

Five patients have died; the other 14 were free from disease at the time of follow-up. Six surviving patients (eight allograft reconstructions) continue to have good or excellent function at a mean of 59 months (14 to 132). One patient has poor function at 31 months. The other seven patients have a good or excellent function after additional procedures including exchange of the allograft and resurfacing or revision to an endoprosthesis at a mean of 101 months (43 to 198). The additional operations were performed at a mean of 47 months (20 to 84) after the first reconstruction.

With the use of allograft reconstruction in growing children, joints and growth plates may be preserved, at least partially. Although our results remain inconsistent, tibial allograft reconstruction in selected patients may restore complete and durable function of the limb.