Many of the bone tumors look very similar and are nearly impossible to differentiate by plain film alone. Initially, one must first determine if the lesion appears slow growing or aggressive. Then, all findings must be properly identified using the appropriate terminology (diagnostic clues). The following terminology would be included in your radiology report of findings. This same terminology would be used to discuss the findings with a radiologist for consultation and would be found in any text you might reference.
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Lateral view, calcaneus. Identify the solitary bone lesion in the superior aspect of the calcaneus, inferior to the posterior talocalcaneal joint. It is geographic and exhibits a sclerotic margin. There is no evidence suggesting break through the outer margin of the bone. These findings typically indicate a slow growing lesion. |
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AP view of distal arm. A spotty, motheaten, or permeative (choose whichever term fits best for you!) loss of bone density can be seen in the distal one-third diaphysis of the radius. There is no definite size or shape to this lesion. This strongly suggests a lesion with aggressive growth activity. |
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Lateral view, foot. This patient presented with heel pain. The lesion is not geographic, and demonstrates mixed increased and decreased density throughout the entire calcaneus. It was confirmed to be a fibrosarcoma, one of the few malignant bone tumors that can demonstrate slow growth activity (i.e., no break through the cortex, no periosteal reaction, etc.). |
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AP view of humerus. Note the motheaten destruction of the distal diaphysis. The cortex is obliterated (osteolysis), and there appears to be invasion of the lesion into the soft tissues. (The soft tissue mass extent would best be evaluated with MRI.) These findings indicate an extremely aggressive lesion, most likely malignant. Also note the pathologic fracture of the opposite cortex. |
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Mortise view, distal leg/ankle. Note the geographic solitary lesion in the distal tibial diametaphysis. Its position is eccentric and demonstrates a sclerotic margin. Though there has been "expansion" of the cortex (the so-called shell periosteal reaction), the cortex is still intact. Also note the "soap-bubbly" appearance (or, lobulated trabeculation) within the lesion. This lesion, in the child or adolescent, is virtually diagnostic of a fibrocortical defect (aka nonossifying fibroma when large in size). It is almost always an incidental finding (the patient is "x-rayed" for some other reason, such as for an ankle sprain). Complications would include pathologic fracture. Fibrocortical defects do heal in adulthood, becoming sclerotic throughout and, if small in size, may disappear. |
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DP view, lesser toes. This patient presented clinically after dropping a heavy object upon her fourth toe. Radiographs were performed to rule out fracture. Indeed, there are fractures (medial cortex and intra-articular, arrows), but they are pathologic fractures. This lytic lesion of the proximal phalanx appears quite aggressive, due to so much bone loss; however, notice the well-defined margins of the bone. This suggests a soft tissue tumor causing pressure atrophy against adjacent bone which was confirmed histologically. |
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DP view, midfoot. This teenager presented clinically with a huge soft tissue mass throughout the midfoot. Radiographically, multiple well-defined, geographic lesions and erosions are located at multiple joints of the midfoot. This was histologically confirmed as pigmented villonodular synovitis. In the literature, this lesion is classically described as being monoarticular. This unique case is multi-articular due to involvement of the great tarsal joint of the midfoot. |
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DP view, fifth metatarsal. A geographic lesion is seen in the distal diaphysis. Some expansion of the cortex is seen laterally, but the cortex remains intact. This was confirmed surgically as a unicameral bone cyst. |
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DP view, third metatarsal. A circular radiolucent lesion can be identified in the diaphysis (arrows). Within it can be seen a faint calcification or nidus. Diffuse sclerosis surrounds the lucent lesion. This is an example of an osteoid osteoma. |
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Medial oblique view, forefoot. A lesion arises from the outer surface of the fourth metatarsal lateral cortex. The outer surface of the cortex is scalloped, and well-defined bone production is seen at its margins. This is possibly a juxtacortical chondroma (aka ecchondroma). Since cartilage is radiolucent, the full extent of the lesion cannot be identified radiographically. |
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DP view of foot. A mixed, complex appearing periosteal reaction involves the second metatarsal distal one-half diaphysis. This exuberant type of periosteal reaction indicates an aggressive underlying process. This particular patient has a primary malignant tumor of the prostate that metastasized to the second metatarsal. (Metastases may either appear lytic, blastic, or both radiographically.) |
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DP view, toes. A geographic, expansile lesion can be identified in the second toe proximal phalanx. It appears somewhat lobulated, and faint calcifications can be identified within it. This location and appearance is fairly characteristic of an enchondroma. |
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Lateral view, left foot. A round, geographic lesion can be identified in the calcaneal "neutral triangle". Note the thin sclerotic margin, indicating slow growth. This is a unicameral bone cyst. Occasionally fat calcifies in the center of this lesion and will appear as an increased density (intraosseous lipoma). These lesions almost always are incidental findings. |
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Lateral view, hallux. Subungual exostosis of the distal phalanx, dome-shaped. The genetic subungual exostosis histologically resembles an osteochondroma, and has a cartilage cap; it is classified as a cartilage tumor, though it appears radiographically as an exostosis. The cartilage cap is not visible radiographically unless it is calcified. |
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DP and lateral views, hallux. Subungual exostosis distal phalanx, plateau-shaped. Note the circular increased density in the DP view (arrow) that appears as a bone island. This is because you are looking axially through the lesion and its attachment site. |
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DP view, lesser toes. Subungual exostosis fifth toe distal phalanx. |
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DP and lateral views, first metatarsal. This patient presented with arch pain. Note the geographic, lytic lesion centered in the proximal diametaphysis. The cortex is expanded, but still intact ("shell" periosteal reaction). Also note the fine, delicate trabeculations within this lesion. This probably is a giant cell tumor. |
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Lateral foot view. A large, geographic lesion encompasses the entire talar body. It is lobulated, with expansion posteriorly. However, the cortex is remains intact. Its internal appearance demonstrates lobulated trabeculations. This lesion was histologically confirmed to be a giant cell tumor. |
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Courtesy John Walter, D.P.M., Philadelphia, PA |
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Mortise and lateral views, distal leg and ankle. A large, geographic lesion can be identified centrally within the distal tibial metaphysis. (Note that it has not crossed the physis nor invaded the epiphysis.) It is expansile, but the cortex is not disrupted. Some trabeculations can be seen within the lesion. This lesion was histologically confirmed to be an aneurysmal bone cyst. |
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Mortise view, distal leg/ankle. Another example of a geographic lesion located eccentrically in the distal tibial diametaphysis. The trabeculations are "coarser" and thicker in appearance than in the above example, but still lobulated or soap-bubbly. Some cortical expansion is noted along with cortical thickening, yet the cortex remains intact. The location and age of the patient suggest a nonossifying fibroma, but the thick/coarse trabeculations suggest chondromyxoid fibroma. Again, this was an incidental finding in a patient who had sprained his ankle. |
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Lateral view, foot. Another large, geographic (its takes the shape of the calcaneal body) lesion demonstrates coarse, thick trabeculations Though there is some "expansion" of the calcaneus, the outer calcaneal margin is still intact. This lesion was confirmed histologically as a chondromyxoid fibroma. |
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DP view, lesser metatarsals. The arrowheads point to a localized increased (cortical-like) bone density in cancellous bone along the endosteal surface of the fourth metatarsal. This lesion is characteristic of a bone island (aka enostosis), and can be found in any bone in the body. It is an incidental finding and not symptomatic. |
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DP view, fifth toe. Osteochondroma proximal phalanx with matrix calcification. Most tumors do not produce calcified matrix; but when they do, a cartilage tumor matrix will appear speckled, stippled, or as rings and arcs. |
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Mortise view, distal fibula and ankle. Another "expansile" lesion. However, its geography cannot be as easily identified as the previous lesions. This would be considered an ill-defined geographic lesion (as opposed to motheaten or permeative destruction). Again, the cortex is intact, but note the hazy or "ground glass" appearance of the center of this lesion. This latter finding is suggestive of fibrous dysplasia. This lesion was another incidental finding; the patient presented with an ankle sprain, and there was no pain associated with the lesion. It was radiographed one and two years later, with no change noted. |
Madewell, JE, Ragsdale, BD, and Sweet, DE: Radiologic and pathologic analysis of solitary bone lesions. Parts I-III. The Radiologic Clinics of North America 19 (4): 715-814, 1981 (Dec).
Resnick, D and Niwayama G: Diagnosis of Bone and Joint Disorders, 2nd Ed., WB Saunders Co., Philadelphia, 1989.
© Copyright 1998, Robert A. Christman, D.P.M.
These articles and figures may not be published, reposted, or redistributed without permission from Dr. Christman.
This page was created May 5, 1998.
Courtesy Dr. Sellig, Glens Falls, NY
Courtesy Louis P. Zulli, D.P.M., Philadelphia, PA
