Malignant Bone and Soft Tissue Tumors - Images Flashcards
Apparent Cortical Destruction.
This benign chondroblastoma has noncalcified chondroid tissue replacing cortical bone in the proximal femur (arrow), which gives this lesion a destructive appearance. This is an example of cortical replacement, rather than cortical destruction, which can be very confusing if one uses cortical destruction as an aggressive or malignant key. Note in this example that the zone of transition is narrow as one would expect in a benign lesion such as this.
Aneurysmal Bone Cyst.
This benign lesion has thinned the cortex to such a degree as
to make it imperceptible (arrow). As in Figure 56.1, this could be misconstrued as cortical destruction, giving the false impression of a malignant or very aggressive lesion.
Periostitis.
A: Benign periostitis. Thick, wavy periostitis (arrows) along the ilium in a child with a permeative lesion in the pelvis is characteristic for infection or eosinophilic granuloma. Ewing
sarcoma was initially considered in the differential; however, the benign periostitis would make a malignant lesion very unlikely. Biopsy showed this lesion to be eosinophilic granuloma.
B: Aggressive periostitis. Lamellated or onion-skin periostitis (arrow) is characteristic of an aggressive process such as
in this patient with Ewing sarcoma of the femur. Again, this aggressive type of periostitis could conceivably occur in a benign process such as infection or eosinophilic granuloma.
Narrow Zone of Transition.
When the margins of a lesion can be drawn with a fine- point pen, as in this example, it is said to be a narrow zone of transition, which is characteristic of a benign lesion. A narrow zone of transition might or might not have a sclerotic border. This is a
nonossifying fibroma.
Wide Zone of Transition.
A lytic, permeative process is seen in the midshaft of the
femur in this patient that on biopsy was found to be a malignant fibrous histiocytoma. The zone of transition in this lesion is said to be wide, as it cannot be easily drawn with a fine-point pen. A permeative lesion such as this, by definition, has a wide zone of transition
Lipoma.
This axial proton-density image through the pelvis shows a large mass lateral to the femur, which has sharp margins and signal characteristics similar to the subcutaneous fat. This is a lipoma. Lipomas will usually contain a small amount of low-signal linear tissue, as in this example, which should not be a cause to consider this lesion malignant.
Hemangioma.
A: A T1-weighted axial image through the midback in a 30-year-old patient with a mass shows a predominantly low-signal mass with stippled areas of high signal
representing fat around numerous vessels.
B: An FSE T2-weighted axial image reveals inhomogeneous
high signal with punctate areas of very bright signal representing vessels. Hemangiomas typically have
mixed fatty and vascular tissue, which gives high signal on both T1 and T2 sequences.
Effect of Fat Suppression.
A: An axial T1-weighted image through the calcaneus shows a low-signal mass that is homogeneously high signal on T2-weighted image.
B: This is the typical appearance of a unicameral bone cyst, which is a fluid-filled benign bone tumor.
C: A sagittal T1- weighted image with fat suppression shows the lesion to be uniformly increased in signal. Had gadolinium been administered, one might wrongly assume this is an enhancing, solid tumor and not a unicameral bone cyst. As no contrast was given, the apparent increased signal is due to the effect of fat suppression.
Osteosarcoma.
A: A mixed lytic and sclerotic lesion in the proximal tibia of a child is noted, which is characteristic for an osteogenic sarcoma.
B: A coronal T1-weighted image shows the full extent of the lesion with some soft tissue extension.
C: These findings are also observed on the T2- weighted image.
Osteosarcoma.
A densely sclerotic lesion in the proximal tibia of a child is seen, which is characteristic for an osteosarcoma.
Parosteal Osteosarcoma.
A: A lateral radiograph of the knee shows a bony lesion emanating from the posterior cortex of the distal femur with a large, calcified soft tissue mass. Note that the densest calcification is central and the periphery is only faintly calcified, characteristics that are typical for a parosteal osteosarcoma.
B: A CT through the lesion reveals the tumor to be invading the
medullary portion of the bone. This is a poor prognostic sign and is an essential information to the surgeon.
Parosteal Osteosarcoma.
A: A lateral radiograph in a different patient with a parosteal osteosarcoma shows soft tissue calcification extending from the posterior femur.
B: A proton- density axial image reveals considerable bony involvement.
Ewing Sarcoma.
An anteroposterior radiograph of the femur of a child shows a predominantly sclerotic process with large amounts of sunburst periostitis in the diaphysis, which on biopsy was found to be Ewing sarcoma
Chondrosarcoma.
Typical snowflake or popcorn-like amorphous calcification in the
proximal humerus is seen, which is typical of an enchondroma. This patient, however, had pain associated with this lesion, and on biopsy, this was found to be a chondrosarcoma.
Chondrosarcoma.
A large soft tissue mass with amorphous, irregular calcification is seen in a lesion arising from the ilium on this CT of the pelvis. This is typical for a chondrosarcoma.
Malignant Fibrous Histiocytoma (MFH) of Bone.
An ill-defined lytic lesion that is permeative or moth-eaten in appearance is seen in the diaphysis of the femur that on biopsy was shown to be an MFH.
Malignant Fibrous Histiocytoma (MFH) of Bone.
A large, lytic, destructive process of the entire right iliac wing (arrows) is noted, which is fairly well defined. On biopsy, this was
shown to be an MFH. MFHs can be very slow growing and will occasionally have a narrow zone of transition such as this.
Desmoid Tumor of Bone.
A multilocular, heavily septated, destructive, lytic lesion of the distal femur is noted in these anteroposterior (A) and lateral (B) radiographs of the femur, which is fairly characteristic for a desmoid tumor. The thick septa and narrow zone of transition are characteristic of a benign process, whereas the Codman triangle (arrow) and large amount of bony destruction indicate
an aggressive process.
Primary Lymphoma of Bone.
A diffuse permeative pattern is seen throughout the humerus in this 35-year-old patient that is characteristic of primary lymphoma of bone
Metastatic Prostate Carcinoma.
Diffuse blastic metastases are seen throughout the pelvis and proximal femurs with a lytic, destructive lesion seen in the right proximal femur (arrow). Prostate metastases tend to be blastic but can occasionally be lytic.
Metastatic Renal Cell Carcinoma.
A lytic lesion in the diaphysis of the femur is noted, which is typical for renal cell carcinoma. As many as one-third of renal cell carcinomas present initially with a bony metastasis. Renal cell carcinoma virtually never presents with a blastic metastatic focus.
Multiple Myeloma.
A diffuse, moth-eaten pattern is seen throughout the diaphysis of the femur in this 45-year-old patient that is characteristic for myeloma. Primary lymphoma of bone could have a similar appearance.
Multiple Myeloma.
A lateral view of the skull shows multiple lytic lesions in the calvarium, which is a characteristic appearance of multiple myeloma.
Synovial Osteochondromatosis.
Multiple calcific loose bodies in a hip joint, as in this example, are virtually pathognomonic for synovial osteochondromatosis. Notice the erosions in the acetabulum (arrows). In up to 20% of cases, the loose bodies are nonossified; in such cases, this process is indistinguishable from pigmented villonodular synovitis.
Pigmented Villonodular Synovitis (PVNS).
Large erosions in the femoral head and acetabulum are characteristic for PVNS; however, nonossified synovial osteochondromatosis could present similarly
Pigmented Villonodular Synovitis (PVNS).
Proton-density (A) and T2-weighted (B) sagittal images of the knee in this patient with painful swelling show diffuse low signal throughout the synovium. The low signal on both T1- and T2-weighted images is typical for hemosiderin deposits in PVNS.
Hemangioma.
Multiple irregular lytic lesions, predominantly cortical in nature, are seen in the tibia in this patient with a soft tissue mass. Cortical holes such as this occur almost exclusively
in radiation and soft tissue hemangioma. Note the phleboliths in the posterior soft tissues (arrows) that
are often seen in hemangioma and make this an easy diagnosis.
Atypical Synovial Cyst.
A: A CT scan through the distal femurs in a patient with a soft tissue mass around the right knee shows a multilocular soft tissue mass adjacent to the distal right femur (arrows).
B: A proton-density MR through the same area shows intermediate intensity signal in a homogeneous multilocular soft tissue mass (arrows) .
C: A T2-weighted image shows high-intensity signal in the lesion, which is typical for fluid, although a tumor could have these signal characteristics. This was an atypicalsynovial cyst arising from the knee joint.
