eMedicine Specialties > Radiology > Musculoskeletal
Adamantinoma
Updated: Mar 19, 2008
Introduction
Background
Adamantinoma is a rare tumor, and its origin remains controversial. Fischer first described the tumor in 1913,7 and since then, only approximately 200 cases have been reported. The tumor occurs almost exclusively in the long bones; tumors in the tibia account for more than 80% of cases. The diaphyseal region is the area most commonly affected.
Adamantinomas are classified into 2 distinct types: classic and differentiated. Classic adamantinomas usually occur in patients older than 20 years, whereas differentiated adamantinomas occur almost exclusively in patients younger than 20 years. In addition, the 2 classifications of adamantinomas have distinct radiographic and histologic differences.
Patients with adamantinomas present with variable signs and symptoms; most commonly, they report pain and swelling. The tumor is slow growing, and patients may describe discomfort lasting months to years. Although ascertaining accurate mortality statistics is difficult because of the extremely rare nature of this tumor, the 10-year survival rate is believed to be 10%. Treatment options for adamantinoma are surgical and include either marginal or en bloc resection. Unfortunately, neither radiation therapy nor chemotherapy has been proven effective in the treatment of this insidious tumor.1,2
Pathophysiology
Although adamantinomas can cause a variety of pathologic and histologic abnormalities, the tumors are usually lobular and well defined. Generally, adamantinomas remain intracortical; however, when prior surgery has been performed or when the tumor is of the classic type, the lesions may extend beyond the periosteum.
The histologic features of adamantinomas have a multitude of variations that are present not only among patients but also among different areas of the same tumor. The histologic features of differentiated adamantinomas are predominantly characterized by a pattern of osteofibrous dysplasia. Conversely, in classic adamantinomas, the cells form a tubular, basaloid, squamoid, or spindled pattern. As a result of the variety of manifestations of the tumor, multiple biopsies must often be performed to obtain a representative sample for study.
Adamantinomas typically range from 3-15 cm in size, and metastases occur in approximately 15-20% of patients. Metastases generally appear in the lungs and local lymph nodes. Adamantinomas can be found in many other bones in addition to their usual location in the tibia. The humerus, ulna, femur, fibula, and radius are other possible locations in the long bones. Occasionally, the tumor occurs in the spine. Adamantinomas are locally aggressive and extremely slow growing.
Related eMedicine topics:
Osteofibrous Dysplasia
Related Medscape topics:
CME Surgery More Effective Than Nonsurgical Treatment for Spinal Stenosis
Pathologic and Radiologic Features of Primary Bone Tumors
Frequency
United States
Because only approximately 200 well-documented cases of adamantinoma have been identified in the almost 100 years since the tumor has been classified, it can be described only as extremely rare.
International
Adamantinomas are extremely rare.
Mortality/Morbidity
Despite their slow-growing nature, adamantinomas can cause significant morbidity and mortality. The 10-year survival rate is estimated to be approximately 10%. In addition, painful bowing deformity of the tibia is not an infrequent occurrence in this condition.
Race
To the authors' knowledge, no racial comparative studies have been performed because of the infrequent occurrence of the tumor and because of the difficult and technologically sophisticated diagnosis. Knowing how many cases have been missed in the less developed regions of the world is impossible, just as knowing how many cases remain undiagnosed in industrialized Western nations is difficult.
Sex
Adamantinomas have a male predominance, with an approximate male-to-female ratio of 1.25:1.
Age
The more common classic adamantinoma usually occurs in individuals older than 20 years, whereas the differentiated form of the tumor almost exclusively occurs in those younger than 20 years. However, the tumors have occurred in individuals aged 10-70 years.3
Anatomy
The tibia is by far the most commonly affected bone; tibial tumors account for 80-85% of primary adamantinomas. Other long bones are also commonly affected; occasionally, primary involvement of the spine occurs.
Presentation
Patients present with complaints such as a dull ache or bone pain that has been present for months to years. Another common complaint is localized swelling. Often, a history of trauma may be elicited. A palpable mass may be firm or soft; its diameter is usually in the range of 3-15 cm.4
Preferred Examination
Plain radiography, CT, and MRI may all be used to help assess suspected adamantinomous tumors. However, CT and MRI are not specific in the differentiation of this tumor from other conditions; findings often overlap with those of other tumors and tumor-like lesions. A variety of tumors and tumor-like lesions can mimic an adamantinoma. Histologic examination is key to the identification of an adamantinoma; the histologic features of these tumors have many variations.5,6
Limitations of Techniques
Limitations of plain-film radiography include the relatively long list of differential diagnoses for adamantinoma. Many pathologic conditions that are as rare as or more common than adamantinoma demonstrate similar characteristics on plain radiographs, as well as CT scans and MRIs. This fact, coupled with the limited experience that most radiologists (and physicians in general) have in dealing with this tumor, makes the diagnosis and treatment of adamantinomas challenging.
Differential Diagnoses
Aneurysmal Bone Cyst
Chondromyxoid Fibroma
Chondrosarcoma
Fibrous Dysplasia
Other Problems to Be Considered
Eosinophilic granuloma
Hemangioendothelioma
Nonossifying or ossifying fibroma
Osteofibrous dysplasia
Simple bone cyst
Radiography
Findings
In its early stages, an adamantinoma appears as an elongated linear lucency on plain radiographs, and no periosteal reaction is noted in the surrounding bone. In later stages, cortical sclerosis becomes apparent on plain radiographs [see Image 1].
The most common location is in the diaphyseal region of long bones, especially the tibia. A periosteal reaction and fracture are less common late-term sequelae of adamantinomas that can also be depicted on plain radiographs.
The differentiation of adamantinoma from fibrous dysplasia and osteofibrous dysplasia may be difficult by using plain radiographs alone. When questions arise in the diagnosis of the tumor, the histologic and clinical features must be included to narrow the differential diagnosis.
Degree of Confidence
Because of the extremely rare nature of this tumor, the degree of confidence has not been determined.
False Positives/Negatives
False-positive findings include fibrous dysplasia, osteofibrous dysplasia, fibroma (nonossifying or ossifying), bone cyst (aneurysmal or simple), chondrosarcoma, chondromyxoid fibroma, eosinophilic granuloma, and hemangioendothelioma.
Because of the extremely rare nature of this tumor, a list of false-negative findings has not been adequately formulated.
Related Medscape topics:
What Is Appropriate Therapy for Fibrous Dysplasia?
Pathologic and Radiologic Features of Primary Bone Tumors
Young Female With Painful Soft Tissue Mass
Computed Tomography
Findings
CT scans often are used to study adamantinomas, but the findings are not specific. CT scans of the lower extremity often reveal a hypoattenuating sclerotic region in the tibial diaphysis [see Image 2].
Degree of Confidence
Degrees of confidence have not been accurately determined because of the rarity of this tumor.
False Positives/Negatives
False-positive findings include fibrous dysplasia, osteofibrous dysplasia, fibroma, bone cyst, and chondromyxoid fibroma.
Magnetic Resonance Imaging
Findings
MRI often is used to image adamantinomas, but the findings are nonspecific. When MRI is used to study adamantinomas, the tumors demonstrate low signal intensity on T1-weighted spin-echo images and high signal intensity on T2-weighted images. Because these appearances are also typical of most tumors, these findings are nonspecific.
Degree of Confidence
Because of the rarity of this tumor, the degree of confidence cannot be accurately determined at this time.
False Positives/Negatives
False-positive findings include fibrous dysplasia, osteofibrous dysplasia, fibroma, bone cyst, and chondrosarcoma.
Related Medscape topics:
Aneurysmal Bone Cyst as a Rare Cause of Spinal Cord Compression in a Young Child
Nuclear Imaging
Findings
Use of nuclear medicine to study adamantinomas is a relatively new undertaking; therefore, few data regarding the tumors have been collected. However, the following findings are believed to correspond to adamantinomous lesions: increased blood flow in the region of the tumor, increased blood pooling, and increased accumulation of technetium-99m methylene diphosphate in the area of the tumor.
Intervention
The only intervention that has been shown to be effective in these tumors is a surgical approach. Neither radiation therapy nor chemotherapy has been proven effective.
Treatment options for adamantinoma are surgical and include either marginal or en bloc resection. Marginal resection of the tumor has been shown to be effective in less than one half of the cases studied; however, en bloc resection generally prevents local recurrence of the tumor.
Multimedia
Media file 1: Plain radiograph in a patient with adamantinoma reveals bony sclerosis, which is typical of a well-established adamantinoma. Courtesy of UCSD Medical Library.
Media file 2: CT scan in a patient with adamantinoma reveals an expansile lesion and superficial erosion on the surface. Courtesy of UCSD Medical Library.
References
Dorfman HD, Czerniak. Bone Tumors. Mosby-Year Book;1998:949-73.
Kitsoulis P, Charchanti A, Paraskevas G, Marini A, Karatzias G. Adamantinoma. Acta Orthop Belg. Aug 2007;73(4):425-31. [Medline].
Gleason BC, Liegl-Atzwanger B, Kozakewich HP, Connolly S, Gebhardt MC, Fletcher JA, et al. Osteofibrous Dysplasia and Adamantinoma in Children and Adolescents: A Clinicopathologic Reappraisal. Am J Surg Pathol. Mar 2008;32(3):363-376. [Medline].
Jain D, Jain VK, Vasishta RK, Ranjan P, Kumar Y. Adamantinoma: A clinicopathological review and update. Diagn Pathol. Feb 15 2008;3(1):8. [Medline].
Resnick D. Diagnosis of Bone and Joint Disorders. Vol 6. Philadelphia, PA: W. B. Saunders Co;1995:3882-4.
Taveras JM. Radiology, Diagnosis, Imaging Intervention. Vol 5. Philadelphia, PA: Lippincott Williams & Wilkins;1993.
Fischer B. Uber ein primares Adamantinom der Tibia. 12. Frankfurt: Zeitschr. f. Path.; 1913:422-441.
Keywords
long bone tumors, classic adamantinomas, differentiated adamantinomas, adamantinomous tumors, primary adamantinomas
Contributor Information and Disclosures
Author
Christopher D Smelser, DO, Staff Physician, Department of Radiology, William Beaumont Army Medical Center
Christopher D Smelser, DO is a member of the following medical societies: American Osteopathic Association
Disclosure: Nothing to disclose.
Coauthor(s)
Robert D Stoffey, DO, Director of Women's Imaging, Department of Radiology, Chief of Mammography Section, William Beaumont Army Medical Center
Robert D Stoffey, DO is a member of the following medical societies: American College of Radiology, American Medical Association, American Osteopathic Association, American Roentgen Ray Society, and Radiological Society of North America
Disclosure: Nothing to disclose.
B Wade Mahaney, MD, Staff Physician, Department of Radiology, William Beaumont Army Medical Center
Disclosure: Nothing to disclose.
Sean C Keenan, MD, Staff Physician, Department of Radiology, William Beaumont Army Medical Center
Sean C Keenan, MD is a member of the following medical societies: American Medical Association
Disclosure: Nothing to disclose.
Gary E Simmons, MD, Chief, Department of Radiology, William Beaumont Army Medical Center
Gary E Simmons, MD is a member of the following medical societies: American Roentgen Ray Society, Radiological Society of North America, and Society of Skeletal Radiology
Disclosure: Nothing to disclose.
Medical Editor
Michael A Bruno, MD, Associate Professor, Departments of Radiology and Medicine, Pennsylvania State University College of Medicine; Director, Radiology Quality Management Services, Milton S Hershey Medical Center, Pennsylvania State University College of Medicine
Michael A Bruno, MD is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America, Society of Nuclear Medicine, and Society of Skeletal Radiology
Disclosure: Nothing to disclose.
Pharmacy Editor
Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.
Managing Editor
Murali Sundaram, MBBS, FRCR, FACR, Consulting Staff, Department of Diagnostic Radiology, The Cleveland Clinic Foundation
Disclosure: Nothing to disclose.
CME Editor
Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute
Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray Society and Radiological Society of North America
Disclosure: Nothing to disclose.
Chief Editor
Felix S Chew, MD, MBA, EdM, Professor, Department of Radiology, Vice Chairman for Radiology Informatics, Section Head of Musculoskeletal Radiology, University of Washington
Felix S Chew, MD, MBA, EdM is a member of the following medical societies: American Roentgen Ray Society, Association of University Radiologists, and Radiological Society of North America
Disclosure: Nothing to disclose.
© 1994-
by Medscape.
All Rights Reserved
(http://www.medscape.com/public/copyright)