IMAGES Chapter 40 - Benign Cystic Bone Lesions Flashcards by Butch Josef Abuel

DIAGNOSIS ? [FIGURE 40.1]

FIBROUS DYSPLASIA

This patient has polyostotic fibrous dysplasia with diffuse involvement of the pelvis as well as the proximal femurs.

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DIAGNOSIS ? [FIGURE 40.2]

FIBROUS DYSPLASIA

This patient has polyostotic fibrous dysplasia with the involvement of the right femur as well as the supraacetabular portion of the ilium. When the pelvis is involved with fibrous dysplasia, the ipsilateral femur on the affected side is invariably also involved.

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DIAGNOSIS ? [FIGURE 40.3]

This patient has a well-defi ned lytic
lesion with a hazy, ground-glass appearance in the neck of the right femur. The pelvis was uninvolved.

FIBROUS DYSPLASIA

It is not unusual for monostotic fibrous dysplasia to involve the proximal femur and spare the pelvis.

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DIAGNOSIS ? [FIGURE 40.4]

FIBROUS DYSPLASIA

When fibrous dysplasia affects the ribs, the posterior ribs often demonstrate a lytic expansile appearance, as
in this example. When the anterior ribs are involved, they are most often sclerotic in appearance.
Note also the involvement of the thoracic spine.

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DIAGNOSIS ? [FIGURE 40.5]

FIBROUS DYSPLASIA

Polyostotic fibrous dysplasia is seen in the radius in this child. Parts of this lesion have a hazy, groundglass
appearance, whereas others are more lytic appearing. A hazy, ground-glass appearance is often present in fibrous dysplasia, but just as often, the appearance can be purely lytic or even sclerotic.

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DIAGNOSIS [FIGURE 40.6]

ADAMANTINOMA

This mixed lytic and sclerotic process in the midshaft of the tibia is characteristic of fibrous dysplasia.
An adamantinoma has an identical appearance and should be considered in any tibial lesion that resembles
fibrous dysplasia.
Biopsy showed this to be an adamantinoma.

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DIAGNOSIS ? [FIGURE 40.7]

ENCHONDROMA

A lytic lesion in the phalanges is most
commonly an enchondroma. This is the only location in the skeleton where an enchondroma does not contain calcified chondroid matrix. These most often present with pathologic fractures, as in this example.

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DIAGNOSIS ? [FIGURE 40.8]

BONE INFARCT

These _lytic lesions in the distal femurs with
calcified, serpiginous borders_are typical of bone infarcts. Occasionally, the differential between a bone infarct and an enchondroma can be difficult on plain films; however, in this example, infarcts are easily diagnosed.

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DIAGNOSIS ? [FIGURE 40.9]

ENCHONDROMA

This lesion in the distal right femur
shows the stippled punctate calcification typical of chondroid matrix seen in an enchondroma.

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DIAGNOSIS ? [FIGURE 40.10]

OLLIER DISEASE

Multiple enchondromas are present throughout the hand. This is a typical example of Ollier disease.

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DIAGNOSIS ? [FIGURE 40.11]

MAFFUCCI SYNDROME

Multiple enchondromas associated with phleboliths are present in the phalanges. This combination
of findings invariably represents hemangiomas and enchondromas in Maffucci syndrome.

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DIAGNOSIS ? [FIGURE 40.12]
A well-defined lytic lesion is seen involving the mid-femur in this 20-year-old patient.

EOSINOPHILIC GRANULOMA

Biopsy showed this to be EG.

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DIAGNOSIS ? [FIGURE 40.12]

EOSINOPHILIC GRANULOMA

Well-defined lytic lesions are present throughout the pelvis in this 24-year-old patient. In addition to the lesion around the right hip, a lesion is seen at the right
sacroiliac joint.

Biopsy showed this to be EG.

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DIAGNOSIS ? [FIGURE 40.14]

EOSINOPHILIC GRANULOMA

This well-defined lytic lesion contains a bony sequestrum (arrow) , which is typical of osteomyelitis or EG.
Biopsy revealed this to be EG.

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DIAGNOSIS ? [FIGURE 40.15]

GIANT CELL TUMOR

A well-defined lytic lesion without
a sclerotic margin is seen abutting the articular surface of the distal femur in a patient who has closed epiphyses. These are all characteristics of a giant cell tumor.

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DIAGNOSIS ? [FIGURE 40.16]

GIANT CELL TUMOR

This well-defi ned lytic lesion that
does not have a sclerotic margin completely involves the greater trochanter. The apophyses have the same differential diagnosis as lesions in the epiphyses, which makes giant cell tumor a strong possibility in this example. Biopsy showed this to be a giant cell tumor.

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DIAGNOSIS ? [FIGURE 40.17]

GIANT CELL TUMOR

A large, well-defined lytic lesion in the iliac wing is seen, which does contain a sclerotic margin and
does not appear to abut any articular surface. The pelvis is a good location for giant cell tumor, which this proved to be at biopsy.
The usual rules for giant cell tumors such as the presence of a nonsclerotic margin do not apply in flat bones.

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DIAGNOSIS ? [FIGURE 40.18]

FIBROUS CORTICAL DEFECT

A well-defined lytic lesion is seen in the medial metaphysis of this tibia (arrows) , which is typical of a fibrous cortical defect.

DIAGNOSIS ? [FIGURE 40.19]

The examination was obtained for a sprained ankle and not for this asymptomatic lesion.

NONOSSIFYING FIBROMA (NOF)

A large, well-defined lytic lesion, which is slightly expansile with scalloped sclerotic margins, is seen in the distal tibia in this young patient. This is a characteristic appearance of an NOF.

DIAGNOSIS ? [FIGURE 40.20]

NONOSSFYING FIBROMA (NOF)

A well-defined, expansile lytic lesion in the distal fi bula is noted in this asymptomatic patient, which is characteristic of an NOF.

DIAGNOSIS ? [FIGURE 40.21]

A. A well-defined, lytic lesion that is minimally expansile is seen in the distal tibia in this child who was examined for a sprained ankle.

B. A CT examination showed apparent cortical destruction
(arrow), which was believed to be suggestive of an aggressive
lesion.

NONOSSIFYING FIBROMA

B. Biopsy showed this to be a nonossifying fibroma. Both
CT and MR will often show apparent cortical destruction,
which is merely cortical replacement by benign fibrous tissue.

DIAGNOSIS ? [FIGURE 40.22]

A predominantly sclerotic lesion, which is minimally expansile and well defined, is seen in the proximal humerus in this child who is asymptomatic.

HEALING, NONOSSIFYING FIBROMA (NOF)

This is a typical appearance of a disappearing or healing NOF.
With time, this lesion will melt into the normal bone and essentially disappear.

DIAGNOSIS ? [FIGURE 40.23]

NONOSSIFYING FIBROMA (NOF)

This large, well -defined lytic lesion with faint sclerotic margins is seen in the distal femur.
Because of its size, many thought it was not an NOF.
The lesion underwent biopsy and was found to be an NOF.

DIAGNOSIS ? [FIGURE 40.24]

OSTEOBLASTOMA

A lytic expansile lesion involving the right T-12 pedicle ( arrow ) and transverse process is seen on this anteroposterior plain fi lm in (A) which is seen on the CT scan (B) to extend into the vertebral body. It has intact cortices and contains some calcifi ed matrix.

This is a classic example of an osteoblastoma of the spine.

DIAGNOSIS ? [FIGURE 40.25] A well-defined lytic lesion is seen in the proximal femur in this 50-year-old patient who has pain associated with this lesion.

**METASTATIC DISEASE** Biopsy showed this to be a renal metastasis. A significant number of metastatic lesions can have a completely benign appearance, as in this example.

DIAGNOSIS ? [FIGURE 40.26]

**MULTIPLE MYELOMA** A. A diffuse permeative pattern is present throughout the femur in this patient with multiple myeloma. B. A lateral skull fi lm shows a typical presentation of multiple myeloma in the skull with multiple small holes throughout the calvarium, which are well defined.

DIAGNOSIS ? [FIGURE 40.27]

**PLASMACYTOMA** A large, well-defined lytic lesion is seen in the left ilium (arrows) in this patient with multiple myeloma. This is a common location for a plasmacytoma. _Like metastases, plasmacytomas often have a completely benign appearance._

DIAGNOSIS ? [FIGURE 40.28] An expansile lesion with a soapbubble appearance is present in the proximal radius in a patient with renal cell carcinoma.

**METASTATIC DISEASE** An expansile lytic lesion is a common finding with renal or thyroid metastatic disease.

DIAGNOSIS ? [FIGURE 40.29] (A) An axial MRI and (B) a CT through the L5 vertebral body reveal a _“mini-brain” appearance_, with the remaining bony struts resembling cerebral gyri and sulci in an anatomic cut brain section. This is characteristic of a \_\_\_\_\_\_.

**PLASMACYTOMA**

DIAGNOSIS ? [FIGURE 40.30] An expansile lytic lesion is present in the distal femur in this 24-year-old patient who presents with pain. This is a fairly typical appearance of an \_\_\_.

**ANEURYSMAL BONE CYST**

DIAGNOSIS ? [FIGURE 40.31] A well-defined expansile lesion is seen in the midshaft of the ulna in a child who presents with pain in this region. This is a characteristic appearance of an \_\_\_.

**ANEURSYMAL BONE CYST (ABC)**

DIAGNOSIS ? [FIGURE 40.32] An axial T2-weighted image through a thoracic vertebral body shows an expansile lesion involving the posterior elements which has several fluid/fluid levels (arrows). This is a typical appearance of an \_\_\_.

**ANEURYSMAL BONE CYST (ABC)**

DIAGNOSIS ? IDENTIFY ALSO THE SIGN POINTED BY THE ARROW. [FIGURE 40.33}

SOLITARY BONE CYST A well-defined lytic lesion is present in the proximal humerus in this child who suffered a fracture through the lesion. The location and central appearance, as well as the age of the patient, are characteristic of a solitary bone cyst. A piece of cortical bone has broken off and descended through the serous fluid contained within the lesion and can be seen in the dependent portion of the lesion ( arrow ) as a _fallen fragment sign_. A _fallen fragment sign_ is said to be pathognomonic for a unicameral bone cyst.

DIAGNOSIS ? [FIGURE 40.34] A well-defined lytic lesion, which is central in location, is seen in the proximal femur in this child. This is characteristic of a \_\_\_\_\_.

**SOLITARY BONE CYST**

DIAGNOSIS ? [FIGURE 40.35] A well-defined lytic lesion is seen in the calcaneus abutting the inferior surface, which is typical in location and appearance for a \_\_\_\_\_.

**SOLITARY BONE CYST** A solitary bone cyst in the calcaneus occurs almost exclusively in this location and is not subject to pathologic fracture as readily as when one occurs in the proximal femur and humerus.

DIAGNOSIS? [FIGURE 40.36] (A) An expansile lytic lesion is seen in the fifth metacarpal (arrows), and a second, smaller lytic lesion is seen in the proximal portion of the fourth proximal phalanx. This patient can be noted to have subperiosteal bone resorption, best seen in the radial aspect of the middle phalanges (B) (arrows) as indistinct, interrupted cortex.

**BROWN TUMOR** This makes the diagnosis of hyperparathyroidism with multiple brown tumors most likely.

DIAGNOSIS ? [FIGURE 40.37] A. A plain film of the proximal humerus in this child with shoulder pain reveals a well-defined lytic lesion in the medial metaphysis. B. A T2-weighted MR of the humerus shows the lesion to have high signal and an associated joint effusion.

**BRODIE ABSCESS** B. The probable site of connection to the joint can be seen (arrow) , which likely represents a draining abscess. Aspiration of the joint fluid revealed pus. This is a large focus of osteomyelitis or Brodie abscess.

DIAGNOSIS ? [FIGURE 40.38]

**OSTEOMYELITIS** A. A lytic lesion is present in the proximal humerus, which has some associated periostitis laterally. B. A CT scan through this area reveals a lytic lesion that contains a calcific density within (arrow), which is a bony sequestrum. This is an area of osteomyelitis with a bony sequestration.

DIAGNOSIS ? [FIGURE 40.39] A plain film in this young patient shows a well-defined lytic lesion in the greater tuberosity of the humerus.

**CHONDROBLASTOMA** Biopsy showed this to be a chondroblastoma.

IDENTIFY the large, well-defi ned lytic lesion in the proximal humerus is present, which is associated with marked degenerative disease of the glenohumeral joint. [FIGURE 40.40]

GEODE or SUBCHONDRAL CYST When definite degenerative joint disease is present and associated with a lytic lesion, the lytic lesion should be considered to be a _geode_. A biopsy was performed, which confirmed this to be a _geode, or subchondral cyst_; however, the biopsy could have been avoided.

DIAGNOSIS ? [FIGURE 40.41] A well-defined lytic lesion in the distal tibia that _extends slightly into the epiphysis_ is noted on this anteroposterior plain film.

**CHONDROMYXOID FIBROMA** A nonossifying fibroma (NOF) could certainly have this appearance; however, this underwent biopsy and was found to be a chondromyxoid fibroma. _Chondromyxoid fibromas often will extend into the epiphysis_, as in this example, whereas NOFs usually will not.

DIAGNOSIS ? [FIGURE 40.42] A plain film of the knee in this 25-year-old patient reveals a sclerotic lesion in the proximal tibia which is a\_\_\_\_\_\_\_\_\_\_.

**HEALING NONOSSIFYING FIBROMA** A plain fi lm of the knee in this 25-year-old patient reveals a sclerotic lesion in the proximal tibia which is a _healing or resolving nonossifying fibroma_.

A large sclerotic lesion is present in the right supra-acetabular region of the ilium (arrow), which represents a \_\_\_. The slightly feathered margins of the trabeculae blending in with the normal bone, and the long axis of the lesion being in the direction of primary weight bearing, are characteristic for a \_\_\_\_. [FIGURE 40.43]

**GIANT BONE ISLAND; BONE ISLAND**