Bone Cysts and Tumors

Question 1

Pre-operative evaluation

Answer 1

• History and physical
• Radiographic evaluation
• labs
• Type of tumor
• Local and distant involvement
• Recurrence rate
• Age
• Occupation
• Lifestyle

Question 2

Lytic lesions

Answer 2

• Lytic lesions that occur in the lower extremity
  are not common, but you need to be aware of
• Boards will include this a great deal

Question 3

Ill- defined lesions

Answer 3

o Indicates that the lesion is a fast growing tumor
o No real parameters
o very hard to determine the area the lesion is limited to
o Hard to tell if surrounding tissues (bone or soft tissue) are affected

Question 4

Well-defined lesions

Answer 4

o AKA a “geographic” lesion

o This indicates that the lesion is slow growing

Question 5

3 types of lesion appearances

Answer 5

• Geographic
• Moth-eaten
• Permeative

Question 6

Example of geographic lesion

Answer 6

Bone cyst

• Very well-defined, geographic lesions
• Cystic changes in the bone are common (bone cyst)
• Not necessarily something you need to treat
• Need for treatment depends on the size of lesion and if any secondary problems are occurring
• Not unusual to see a pathological fracture around this – this then NEEDS to be treated
• If no pathological fractures, you can just do serial radiographs over a number of years

Question 7

Example of moth eaten appearance

Answer 7

• Multiple lucent changes that are not well defined
• This is a very good example of what a moth-eaten appearance
• NEED to know this image ***

Question 8

Example of permeative appearance

Answer 8

• No true beginning or end, no well-defined area
• On the left side, you see some subtle changes, but no well-defined area
• Same thing on the right – you see some lucent lytic changes
  but you also see that more proximally as well

Question 9

NOTE - clinical approach to diagnosing bone lesions

Answer 9

• The first thing you do is determine the appearance (geographic, moth-eaten,
  or permeative), which will give you an idea of how benign or malignant the lesion is
• Geographic is typically the most benign, permeative is typically the most malignant
• The next step is to assess the margins and periosteal reaction…

Question 10

Narrow margins

Answer 10

o 0.1-1.0 mm tumor and surrounding normal bone are touching, and you see a very small distance between them
o Usually can’t tell the difference between 0.1 and 1.0 mm – just know it is very narrow

Question 11

Wide margins

Answer 11

o 2-10 mm can see where the tumor is, and you can see where there is undamaged bone, but in between the two there is an area that is indistinct that looks like it might be partially damaged

Question 12

Poorly defined margins

Answer 12

o Correlates with permeative lesions
o May be several centimeters or it may be impossible to measure the margin
o One can tell there is a tumor in the bone, and there are areas that are distinctly abnormal, but you can’t tell how big the lesion is or where it begins or ends

Question 13

NOTE about margins

Answer 13

o The margins will also correlate to the level of aggressiveness (benign vs. malignant)
o If you have a narrow, well defined margin, it is typically a more benign lesion
o If you have a wide margin, there is likely activity taking place there, more aggressive and more likely to be malignant

Question 14

Description of periosteal reaction

Answer 14

• Periosteal reaction is an indicator of biologic activity of the bone lesion, indicating a more aggressive tumor
• This occurs on the outside of the bone (associated with the periosteum)
• If the lesion is expansive or if there is a lot of bone activity, you will likely see periosteal reaction associated with it

Question 15

Types of periosteal reaction

Answer 15

o	Solid 
o	Lamellar
o	Multilamellar
o	Spiculated
o	Buttress
o	Codman’s triangle

Question 16

Solid periosteal reaction

Answer 16

o There is expansion of the lesion, but it is growing at a slow enough rate that the bone is able to keep up with it and lay down new bone surrounding the growth – this allows for a solid periosteal reaction

Question 17

Lamellated periosteal reaction

Answer 17

o Multiple layers of periosteal reaction which appears like an “onion skin”
o The lesion is growing, but again the body does have a chance to lay down bone, but in this case it is in multiple layers

Question 18

Spiculated periosteal reaction

Answer 18

o “Sun-burst” or “hair-on-end” appearance
o Sharpey’s fibers become stretched out perpendicular to the bone, and then ossify
o The body does NOT have a chance to lay down a solid layer of bone due to the rapid growth of the lesion
o Results in a spiculated or “sun burst” reaction which appears like a “hair on end”

Question 19

Codman’s periosteal reaction

Answer 19

o Only the edges of the raised periosteum will ossify
o This little bit of ossification forms a small angle with the surface of the bone, but not a complete triangle
o Very aggressive, again the body does not have a chance to lay down bone due to very rapid growth

Question 20

Example of spiculated periosteal reaction

Answer 20

• What the diagram looks like and what the radiograph
  looks like can be very different
• In this example, you mostly see a light “rim” around the
  lesion where it looks “fluffy”
• You don’t actually see all the little spicules coming out of
  the bone

Question 21

Example of Codman’s triangle

Answer 21

• Only the edges of the raised periosteum will ossify
• This little bit of ossification forms a small angle with
  the surface of the bone, but not a complete triangle
• You will NEED to do some type of biopsy which will give
  you more definitive information

Question 22

Example of lamellar periosteal reaction

Answer 22

• This is a good example of what lamellar or onion skinning

will look like, you can see the actual layers

Question 23

Staging of benign lesions

Answer 23

o Stage 1: lesions that are static or tend to heal spontaneously.
o Stage 2: lesions that present with a more aggressive radiographic presentation, and evidence of continued growth.
o Stage 3: locally aggressive lesions, and show progressive growth not limited by barriers – can see invasion into cortical bone or joints.
o Stage 2 and 3 are histologically immature

Question 24

Treatment for benign stage 1 and 2

Note: treatment is based on STAGE***

Answer 24

o Intra lesional curettage

o Reconstructed with cancellous bone grafting, methyl methacrylate augmentation

Question 25

Treatment for benign stage 2 and 3

Note: treatment is based on STAGE***

Answer 25

o Over treat with marginal excision that removes the intra articular surface with associated fusion – take more than just the lesion to assure complete removal

Question 26

Adjunct therapy for benign lesions

Answer 26

o Cryotherapy where you remove healthy bone in the area with either phenol or polymethacrylate – used in combination with the bone packing

Question 27

Staging of malignant lesions

Answer 27

o Stage 1: low grade lesions
o Stage 2: high grade lesions
o Stage 3: presence of metastasis

Question 28

Treatment for malignant stage 1 lesions

Note: treatment is based on STAGE***

Answer 28

o Requires a wide marginal excision, may require a partial or complete amputation at the appropriate level

Question 29

Treatment for malignant stage 1B (hybrid of stage 1 and 2) and stage 2 lesions

Note: treatment is based on STAGE***

Answer 29

o Reconstruction and/or amputation, but this will be more aggressive
o If unsure, consult oncology, especially if chemotherapy/radiation may be necessary

Question 30

Bone biopsy types

Answer 30

• Fine needle biopsy
• Core needle biopsy
• Excisional biopsy

Question 31

Principles of bone biopsy

Answer 31

Incision placement and orientation
o Longitudinal and based on the anticipated area of resection
o Performed without the formation of tissue planes
o Hemostasis

• Dissection should be carried out sharply to the level of bone and remain within one fascial compartment
• Soft tissue mass sent if present
• Cortical window created
• Closed in layers

Question 32

CASE STUDY I

Answer 32

• 12 year old male presents with a chief complaint of right heel pain 2 weeks duration
• Initial presentation secondary to increase in level of activity
• PMH: unremarkable, Med: none, NKDA
• Initial treatment: ibuprofen 600mg. Bid, modify level of activity.
• What are some differentials that would be appropriate for a 12 year old male? Fracture, NOT plantar fasciitis (not in adolescents), Sever’s disease, bone cyst
• CT shows a large lytic lesion in the calcaneus

Question 33

Treatment for CASE STUDY I

Answer 33

o Creation of a cortical window, curettage of tumor and adjacent bone
o Packing of the defect (tri-cortical graft) iliac crest
o Below knee cast and non-weight bearing (until you start to see integration)

Question 34

CASE STUDY II

Answer 34

• 37 year old male presents with pain to the right hallux of 4 months duration. Pain associated with ambulation and weight bearing activities.
• Bone scan shows increase in uptake in the proximal portion of the hallux
• MRI shows pathology in the base of proximal phalanx – lesion is present here and it is well-defined (you see some gray uptake, but that is just swelling)

Question 35

Treatment for CASE STUDY II

Answer 35

o Treatment: excision of the lesion with bone curettage
o Packing with allogenic bone graft
o You can see the bone packing on radiographs post-op

Question 36

CASE STUDY III

Answer 36

• 14 year old male presents with a history of heel pain, unresponsive to conservative treatment
• Radiographs show a very large, well-defined lytic lesion of the calcaneus
• Patient taken to surgery, bone window created and defect packed with allogenic bone graft matrix, then you put the bone window back on to increase stability on the lateral calcaneus
• The pathology report indicated findings consistent with an aneurysmal bone cyst

Question 37

CASE STUDY IV

Answer 37

• 27 year old female presents with a chief complaint of stiffness and periodic pain in ankle joint
• PMH: unremarkable, neuro/vascular intact, musculoskeletal: limited ROM of the ankle joint
• X-ray shows portion of normal tibia with area of lucent change in medial portion of distal tibia
• MRI shows a well-defined lesion, consistent with the radiographs
• The MRI is used to determine if there is any soft tissue involvement and here we see that the lesion is limited to the tibia

Question 38

Diagnosis for CASE STUDY IV

Answer 38

Diagnosis is an Intra-osseous ganglion
o Just by looking at it you can tell it is a ganglion (sac filled with viscous or gel material)
o Typically ganglions are associated with tendons, ligaments or capsular structures
o Here we see the ganglion associated with the articular surface of the bone

Even though it looks like a ganglion structure, you would still send to pathology just to be safe

Question 39

CASE STUDY V

Answer 39

• Patient presents with pain and large prominence along the 5th metatarsal head
• Lesion is dorsally and plantarly located, comes close to bone
• MRI shows that it is a well-defined lesion, even though there is invasion into the soft tissue, it is not integrated into the soft tissue, it is still its own structure – This is the important information you can gain by looking at MRI
• Diagnosis was a chondroma – this in itself is not necessarily a bone tumor, but it is a tumor associated with the articular surface
• Any time you have a lesion, you need to have a good understanding of the pathology

Question 40

CASE STUDY VI

Answer 40

• 57 year old female presents with a recent onset of severe pain to the hallux.
• PMH: NIDDM w/ neuropathy, HTN
• Objective findings: DP and PT +1/4, epicritic sensation intact, atrophic, scaly, xerotic skin, +5/5 extrinsic muscles, pain on palpation to the hallux
• MRI shows increase in activity, lesion present within the base of the proximal phalanx
• Treatment consists of curettage and packing the area
• Follow up MRI shows a walled off appearance of the bone packing site

Question 41

CASE STUDY VII

Answer 41

• An 11 year old male presents with a chief complaint of a left painful 2nd digit with no history of trauma, pain associated with shoe gear
• PMH: unremarkable, meds: none, surgical history: none
• The first radiograph taken shows a tiny change in the bone, the second radiograph taken 1 month later shows a fast growing lesion is present at the distal phalanx
• Treatment: Symes amputation of the 2nd digit – just removed a part of the distal bone, no soft tissue loss was necessary
• Pathology report: findings consistent with chondroma (non-malignant)