Diagnostic Features of Bone Tumors

History

Age, Pain

AGE

The patient’s age and clinical presentation are very helpful in predicting the diagnosis in musculoskeletal tumors and greatly aid in the interpretation of the imaging studies. Following are typical ages for common bone tumors:

3–10 years: Langerhans cell histiocytosis, unicameral bone cyst, osteomyelitis
10–15 years: nonossifying fibroma, chondroblastoma, osteosarcoma, Ewing sarcoma
15–20 years: osteosarcoma, osteoid osteoma
20–30 years: giant cell tumor
30–50 years: metastatic carcinoma, malignant fibrous histiocytoma (MFH) and fibrosarcoma of bone, lymphoma in bone
>50 years: metastatic carcinoma, multiple myeloma, chondrosarcoma, Paget disease, Paget sarcoma, MFH and fibrosarcoma of bone, lymphoma in bone

PAIN

The presence or absence of a history of pain can aid in the diagnosis of bone tumors. Many benign indolent tumors are detected incidentally during unrelated radiographic evaluation, whereas benign aggressive and malignant bone tumors are almost always painful.

Pain Timing

The nature of the pain is important to understand. Is pain related to activity or present at rest? Traumatic and degenerative conditions (e.g., meniscal tears, pictured ) do not cause night pain.

Pain Location

Examination helps to determine whether the lesion in question is the cause of pain. For example, knee bursitis pain and spinal (radicular) pain are sometimes incorrectly ascribed to asymptomatic bone tumors in the femur, as in this incidentally discovered enchondroma. Cartilage rests are frequent about the knee and are seen in 2.9% of the population undergoing MR examination.

Location

Location in Bone, Skeletal Distribution

LONGITUDINAL LOCATION

The location of a tumor in bone is of great significance. Each region of bone has biologic properties that predispose it to different tumors. Location in bone is described in two axes: longitudinal and axial. Longitudinal location refers to the epiphysis, metaphysis, or diaphysis of bone.

Epiphysis Typical tumors at this site include chondroblastoma ( pictured ), giant cell tumor (with contiguous involvement of the metaphysis), subchondral cyst, and infection.	Metaphysis Typical tumors at this site include nonossifying fibroma ( pictured ), aneurysmal bone cyst, giant cell tumor (often with contiguous involvement of the epiphysis), and osteosarcoma.
Diaphysis Typical tumors at this site include fibrous dysplasia, histiocytosis, adamantinoma, Ewing sarcoma ( pictured ), and multiple myeloma.	Map of Neoplasms This figure demonstrates typical locations for a variety of benign and malignant bone tumors. (Courtesy of Aletta A. Frazier, MD)

AXIAL LOCATION

The axial location of a tumor is also predictive of the diagnosis. Axial location in bone is described as central medullary, eccentric medullary, intracortical, or juxtacortical/surface.

Central Typical tumors with a central medullary location include enchondroma ( pictured ), fibrous dysplasia, unicameral bone cyst, and round cell tumors (e.g., lymphoma, Ewing sarcoma).	Eccentric Typical tumors with an eccentric medullary location include nonossifying fibroma ( pictured ), aneurysmal bone cyst, and giant cell tumor and osteosarcoma.
Intracortical Typical tumors with an intracortical location include osteoid osteoma ( pictured ) and osteofibrous dysplasia.	Juxtacortical/Surface Typical tumors with a juxtacortical location include osteochondroma, periosteal chondroma, and osteosarcoma surface variants, such as periosteal and parosteal osteosarcoma ( pictured ).

SKELETAL DISTRIBUTION

Although it is generally more important to recognize the location within bone of a tumor, in some cases knowing the particular affected bone can aid in diagnosis. Following are examples of tumors with distinctive skeletal distributions.

Unicameral Bone Cyst The most common location for unicameral bone cysts is the proximal humerus, and the second most common location is the proximal femur.	Adamantinoma The vast majority of adamantinomas are discovered in the tibial diaphysis.
Chordoma This tumor is almost exclusively found in the clivus (skull base) and the sacrum.	Metastatic Carcinoma Metastatic lesions are rare distal to the elbow and knee. Therefore, bone tumors in the distal extremities, even in adults, are unlikely to be carcinomas.

Margins

Pattern of Bone Lysis and Zone of Transition, Periosteal Reaction

PATTERN OF BONE LYSIS AND ZONE OF TRANSITION

Tumor margins, that is the interface between tumor and normal bone, are highly predictive of the aggressiveness of the tumor. Margins are described with two parameters: by the pattern of lysis and by the width of the zone of transition into normal bone. Bone lysis can be geographic, motheaten, or permeative. Geographic lysis represents a single focus of bone destruction. Motheaten and permeative patterns of lysis are produced by multiple small destructive foci of tumor. The zone of transition can be narrow, reflecting indolent growth, or wide, reflecting more rapid growth. Tumors with geographic lysis can have a narrow or a wide zone of transition. Tumors with motheaten and permeative lysis, by definition, have a wide zone of transition.