Solitary bone lesions
Lecture no. 2
Prepared by Dr.Salah Mohammad Fatih
MBChB,DMRD,FIBMS(radiology)
Radiological approach for diagnosis of
solitary bone lesions
 1st try to decide whether the lesion is benign (i.e.
stable or very slow growing) or whether the lesion is
aggressive (malignant tumor or infection).
1. Age of the patient.
 This can be an extremely important determinant in some
lesions in which the age range of occurrence may be quite
narrow. For example,
Malignant osseous lesions in patients;
 under one year ; metastatic neuroblastoma.
 age range of 1 to 30 years ; osteosarcoma or Ewing's
sarcoma.
 In the 30- to 60-years range ; chondrosarcoma, primary
lymphoma, or malignant fibrous histiocytoma,
 age range over 50 ; metastatic disease or multiple myeloma.
2-Location of the lesion
Three different types of locations should be noted:
1- the particular bone that is involved. ( long bone ,flat bone , small
bones)
3- the location in a transverse axis. (central, eccentric, or a corticallybased).
3- the location in a longitudinal axis of a long bone. (epiphysis,
metaphysis or diaphysis).
Certain lesion occur at the certain sites;
E.g. Osteomyelitis characteristically occur in the metaphyseal areas
specially of the knee & lower tibia whereas giant cell tumor occur in
subarticular areas
3- zone of transition
i.e. Zone of transition of the lesion from abnormal to
normal bone;
 A wide zone of transition denotes an aggressive lesion.
 A narrow zone is a much less aggressive lesion.
 well defined sclerotic edge is almost certainly benign.
4- adjacent cortex
 Any destruction of the adjacent cortex indicates an
aggressive lesion such as a malignant tumor or
osteomyelitis
5- Expansion
 Bone expansion with an intact well formed cortex
usually indicate a slow growing lesion such as an
encondroma or fibrous dysplasia.
6-periosteal reaction
 Presence of an active periosteal reaction in the
absence of the trauma usually indicates an aggressive
lesion
7-Soft tissue involvement
 . Cortical breakthrough of a bone lesion to create a soft tissue mass
generally suggest an aggressive lesion (infection or tumor) .
 ill define soft tissue swelling adjacent to focal bone destructive lesion
suggest infection .
 well define soft tissue swelling adjacent to the bone lesion suggest
neoplasm& such soft tissue masses will often distort but not obliterate
nearby muscle planes.
8-Pattern of bone destruction
 Common terminology includes ;
 "geographic" (well-defined or map-like lesion, the least aggressive pattern),
 "moth-eaten" (holes, with less well-defined margins, appearing more
aggressive)
 "permeative" (a poorly demarcated pattern which is often very difficult to
visualize and represents a highly aggressive lesion)
9. calcific densities within the lesion (tumor
matrix)
allow categorization of a lesion as bone producing
versus cartilage producing.
 Diffuse ill defined calcification within the lesion suggest
osteoid lesion .
 presence of a patchy calcification of popcorn or stippled
type with density more than normal bone usually indicate
cartilaginous tumor
10-Size of the lesion
 Generally, a larger lesion (greater than 5 cm) is more
likely to be malignant or aggressive, but there are
many exceptions to this statement, and other
determinants are generally more important than this
one.
11. Polyostotic versus Monostotic
 This is the last most important point , since polyostotic lesions automatically
restrict the number of disease processes that might be considered. For example,
nonaggressive polyostotic lesions should be confined to;
 fibrous dysplasia
 Paget's disease
 Histiocytosis
 multiple exostosis
 multiple enchondromatosis
Aggressive polyostotic lesions would be confined to
 osseous metastases
 multiple myeloma
 primary bone tumor with osseous metastases,
 multifocal osteomyelitis, aggressive histiocytosis, and multifocal vascular bone
tumors.
Bone tumors
Investigations;
1- plain film radiography in general is the best
imaging technique for making the Dx.
2- MRI&CT often shows the full extend of the tumor &
show the effects on the surrounding structures& the
relation ship to the neurovascular bundles
3- Isotope scan is used to Dx metastatic bone disease
Primary bone tumors
1- malignant
2- benign
1- primary malignant bone
tumors
1- plain radiograph; usually have;
 Wide zone of transition
 Poorly defined margin.
 Lesion may destroy the cortex.
 Periosteal reaction is often present.
 Soft tissue mass may be seen.
Poorly defined margin & wide zone of
transition.
Periosteal reaction
destroy the cortex
Soft tissue mass
2- Isotope scan
Malignant bone tumor show increased activity in
the lesion.
3-MRI
 MRI is the most accurate technique in showing the
local extend of the tumor with the advantage that
images may be produced in coronal & sagittal planes &
MRI provides this information better than CT
Osteosarcoma(osteogenic sarcoma)
 Age ; mainly 5-20 years but also seen in elderly
following malignant transformation of paget’s disease.
 Location;Is often arise in the metaphysis, most
commonly around the knee joint.
 X-ray finding;
1. often there is bone destruction & new bone
formation with typical florid speculated periosteal
reaction(sunray appearance).
2. The tumor may elevate periosteum to form Codman’s
triangle
Chondrosarcoma
 Age; 30-60 years
 Site; most common sites are pelvic bones, scapulae,
humerie & femorae
 Radiographic finding;
1. It produce lytic expansible lesion contains flecks of
calcification.
2. It can be difficult to be distinguished from its benign
counterpart (enchndroma), but condrosarcoma usually less
well defined in at least one portion of its outline & may
show a periosteal reaction & soft tissue component.
chondrosarcoma may arise from malignant degeneration of
the benign cartilaginous tumors.
Ewing sarcoma
 Is a highly malignant tumor.
 Age; most commonly occur in the children ,usually
between 5-15 years.
 site; it arise mostly in the long bone, usually in
diaphyseal region.
 X-ray finding;
 It produce an ill define bone destruction with
periosteal reaction that is typically onion skin in
appearance.
Giant cell tumor
 Has features of both malignant & benign tumor, it is locally
invasive but rarely metastasizes.
 Age; usually 20-40 years.
 site; it is most commonly occur around the knee & wrist
after the epiphysis have fused.
 X-ray finding;
 Expanding destructive lesion which is subarticular in
position.
 the margin is fairly well defined but the cortex is thin &
may be in places completely destroyed.
2-Benign bone tumors
 Common x-ray finding;
 Narrow zone of transition with sclerotic rim.
 Cause expansion but rarely produce cortical
breakdown .
 periosteal reaction is unusual unless there is has been
a fracture through the lesion.
 There is no soft tissue mass .
 Isotope scan; shows little or no increase in the
activity unless fracture has been occurred through
the lesion.
 MRI & CT scan: are rarely needed in their evaluation
Encondroma
 Are seen as lytic expanding lesion .
 Most commonly seen in the hand.
 They often contain flecks of calcium & frequently
present as a pathological fracture.
Fibrus dysplasia
 May affect one or more bone
 It occur most commonly in the long bones& ribs.
 Radiologically it appear as lucent area with a well
defined edge and may expand the bone, there may be
sclerotic rim around the lesion
Simple bone cyst
 Occurs in children & young adult.
 Most common sites are humerous & femur
 X-ray;
 Lucency across the width of the shaft of the bone with
well defined edge.
 The cortex may be thin & the bone expanded.
 Often the 1st clinical finding is pathological fracture
Aneurysmal bone cyst
 are neoplasm.
 Mostly seen in children & young adult.
 Common site; spine, long bone & pelvis.
 Radiological finding;
1. X-ray; purely lytic & cause massive bone
expansion of the cortex.
2. CT & MRI may show the blood pool within the
cyst.
3. Major differential Dx is Giant cell tumor
Oseoid osteoma
 Is a painful condition found most commonly in the
femur & tibia in young adults.
 Radiological appearance; it has a characteristic
appearance;
Small lucency sometime with central specks of
calcification (nidus) surrounded by dense sclerotic
rim & periosteal reaction may be seen.
oseomyelitis
 Usually occur in infant& children.
 Initial radiographic appearance is normal & bone
changes are not visible until 10-14 days of the infection.
 Most sensitive imaging modalities are isotope scan &
MRI which may shows the disease within 1-2 days.
Acute oseomyelitis
 Typically affect metaphysis of the long bone.
 X-ray finding;
 The earliest sign on the plan radiograph is soft tissue swelling with
characteristic obliteration of fat plains & may be apparent within 1st 2
days of the clinical manifestations.
 local osteoporosis may be seen within 10-14 days of the onset of the
symptoms.
 bone destruction in the metaphysis with periosteal reaction that
eventually may become very extensive & surround the bone to form
involucrum which is usually visualized after 3 weeks.
 Part from the original bone may die & separate to form dense fragment
called sequestrum.
sequestrum
 Isotope scan; increased activity in both early & delay
phase.
 MRI; is the investigation of choice & may shows
evidence of bone edema & pass accumulation in the
bone & soft tissue
Chronic oseomyelitis
 The bone become thickened & loss differentiation
between the cortex & the medulla
TB oseomyelitis
 Spine is the most common site followed by large
joints, but any bone may be affected.
 The disease produce large areas of bone destruction &
unlike pyogenic infection, the disease is relatively
asymptomatic in the early stage.