A 14-year-old girl presented with pain and swelling in her right leg for 4 months. Imaging showed an expansile lytic lesion in her tibia consistent with an aneurysmal bone cyst. She underwent surgery involving curettage of the lesion and fixation with a fibular bone graft and plate. Histopathology of the removed tissue confirmed the diagnosis of aneurysmal bone cyst. Her post-operative recovery was uneventful and follow-up showed good healing of the bone.

1. Swelling of the right
leg for diagnosis
by. Dr. Giridhar Boyapati
PG.
Dept. of Orthopaedics

2. CASE REPORT
 A 14 year old girl presented with chief complaints of pain
and swelling of right leg since 4 months.
 Pain in middle third of leg which is insidious in onset,
progressive in nature, dull aching continuous type of pain.
Aggravated by weight bearing. Relived by rest and
medication.
 Swelling is gradually progressive in size . Not associated
with edema of the limb.
 No history of trauma ,fever , chronic cough.

3.  No history of recent significant loss of appetite or
weight loss.
 No other co-morbid conditions, otherwise a healthy
individual.
 Family history: no similar complaints in family members.
No history of contact with pulmonary tuberculosis .
 Menstrual history: attained menarche, no menstrual
irregularities.

4. GENERAL EXAMINATION
Pallor present. No clubbing , no icterus no
generalized lymphadenopathy.
No similar swellings elsewhere in the body, no
thyroid and breast swellings.
CVS/CNS/RS : NAD
Abdomen: soft, non tender, no organomegaly.
No signs of infection or any chronic disease.

5. LOCAL EXAMINATION
 Swelling of size 10x5 cm over the anterior aspect of
proximal right leg.
 Skin over the swelling is normal, no trophic changes ,no
scars and sinuses, no dilated veins.
 Firm bony swelling with ill-defined margins, slightly tender.
 Local rise of temperature present.
 The swelling is continuous with tibia proximally and
distally, moving along with tibia.

6. LOCAL EXAMINATION
No muscle wasting.
Fibula is palpable separately from the swelling.
No pulsations, no bruit heard over the swelling.
 Movements at knee and ankle joint are normal. Active toe
movements present.
No distal neurovascular deficit.

7. PRE OP PHOTO
Swelling of the Right leg
skin condition normal.

8. PROVISIONAL
CLINICALDIAGNOSIS
Bony swelling arising from diaphysio-metaphyseal junction of right
tibia; with out any pressure effects.
1. Aneurysmal bone cyst.
2. Unusual presentation of Simple bone cyst.
3. Osteochondroma.
4. Ewing's sarcoma.
4. Telangiectatic osteosarcoma.
5. Fibrous dysplasia.

9. INVESTIGATIONS
Normocytic Normochromic anemia.
No infection
Urine routine is normal.
HB 9.0gm%
PCV 27%
TWC 82OOcells/c
umm
ESR 15mm 1st hr
BT 2min
CT 4min
CRP NEG

10. INVESTIGATIONS
Chest X-RAY normal study RBS 92 mg%
SODIUM 140 meq/l
potassium 4.2 meq/l
T.bilurubin 0.5 mg%
B.urea 12 mg%
S.creatinine 0.6 mg%
ALP 40 IU/L

11. RADIOGRAPH
Standard Anterior- posterior
and LATERAL views of the
right leg

12. RADIOLOGY REPORT
Expansile lytic lesion located in postero-lateral
aspect of tibia with thin internal
septations which are thickened trabecule
noted in the diaphysis.
Lesion shows thin cortex.
Finger in balloon sign.
Fibula appears to be normal.
No soft tissue swelling adjacent to the lesion

13. DIFFERENTIAL DIAGNOSIS
After radiographic study:
1.Aneurysmal bone cyst.
2.Unicameral bone cyst.
3. Giant cell tumor of bone.
4. Telangiectatic osteosarcoma.

14. FURTHER EVALUATION
C.T
M.R.I
BONE SCAN
F.N.A.C/BIOPSY

15. C.T 3D RECONSTRUCTION
CT showing lytic
lesion

16. MRI OF RIGHT LEG

17. MRI

18. MRI
Expansile lesion arising from right tibia measuring 9x5x4cm
Lesion is multiseptated and multiloculated.
Frank breach seen in the posterior cortex.
T1W heterogenous with signal intensities varying from iso-hyperintense.
T2W significantly hyper intense.
Multiple fluid-fluid levels.
No joint extension.
Minimal edema in adjacent muscles in the posterior part.

19. CONTRAST MRI
After contrast study, the walls and septations are
enhancing.
cyst contents and blood products are not
enhancing.

20. M.R.I IMPRESSION
Bone lesion at upper diaphysis of right tibia is
more in favor of
Aneurysmal bone cyst
other possibilities:
1. Hemorrhagic Simple bone cyst
2.Telengectatic osteosarcoma

21. BONE SCAN
 3 PHASE BONE SCAN
 Using Tc-99 MDP.
 Photon deficient area with Rim
of intense tracer uptake noted in
proximal shaft of right tibia –
Aneurysmal bone cyst.
 No evidence of any other lesion
on whole body skeletal survey.

22. FNAC
Smears show hemorrhagic
background with
occasional multinucleate
giant cells and
inflammatory background.
IMPRESSION: cytological
features are suggestive of
aneurysmal bone cyst.

23. CULTURE SENSITIVITY OF
ASPIRATE
 No bacterial growth after 48hrs.
 Gram staining and AFB were
negative

24. FFIINNDDIINNGGSS AA..BB..CC SSIIMMPPLLEE
. CCAASSEE
BBOONNEE CCYYSSTT
TTEELLAANNGGIIEECCTTAATTII
CC
OSTEOSA
RCOMA
GGAAIINNTT CCEELLLL
TTUUMMOORR
AAGGEE 14yr 10-20yr 10-20yr >30yr >30yr
SSEEXX female female male male female
SSIITTEE DIAPHYSIS
METAPHYSIS
RARELY
DIAPHYSIS
METAPHYSIS METAPHYSIS EPIPHYSIS
AAPPPPEEAARREENNCCEE ECCENTRIC ECCENTRIC CENTRAL CENTRAL ECCENTRIC
MULTIPLE
MMRRII
FLUID -FLUID
LEVELS
MULTIPLE
FLUID-FLUID
LEVELS
NO
MULTIPLE
FLUID -FLUID
LEVELS
NO
GGRROOSSSS
AAPPPPEEAARRAANNCCEE
BLOOD FILLED
CYSTIC SPACES
BLOOD FILLED
CYSTIC SPACES
CYST
CONTAINING
CLEAR SEROUS
FLUID
BLOOD FILLED
CYSTIC SPACES
BLOOD FILLED
CYSTIC SPACES

25. MANAGEMENT
Patient was advised surgical management.
INDICATION FOR SURGERY
 1.To prevent pathological fracture.
 2. For open biopsy to rule out malignant tumors.
Informed consent was taken from the patient and
her attenders for surgery.

26. MANAGEMENT
EXTENDED CURETTAGE,
FIBULAR BONE GRAFTING
AND FIXATION WITH
DYNAMIC COMPRESSION
PLATE.

27. SURGICAL APPROACH
Under tourniquet
to reduce blood
loss
Anterolateral
approach to
proximal tibia.
S shaped incision.
Tibialis anterior is
retracted laterally
to expose the
lesion.

28. EXPOSING THE
LESION
Lesion is about 10x5
cm involving
proximal tibial shaft.
Soft cystic swelling
surrounded by thin
cortical bone.

29. CURETTAGE
Entire lesion is
curetted and
removed
No surrounding
soft tissue
involvement
Material sent
for
histopathology.

30. FIXATION
After curettage only
antero-medial cortex of
tibia is left intact.
To prevent any fracture,
fixation along with bone
grafting is required.
Lesion is not involving the
Fibula

31. OBTAINING FIBULAR GRAFT
Fibular graft is
obtained from left
leg.
This graft is used to
provide additional
support for right
tibia.
Fibula is split
vertically and
fixed in medullary
canal of tibia.

32. Fibula
graft

33. POST OPERATIVE X-RAY
OF LEFT LEG
fibula graft .

34. FIXATION
Tibia is fixed using
10 holed D.C.P
and screw
fixation along
with fibular
grafting.

35. POST OPERATIVE
X-RAYS
showing tibia fixed
with plating and
screw fixation and
fibular grafting.

36. POST OPERATIVE PERIOD
Post operative period is uneventful
No h/o fever.
No postoperative wound complications.
After suture removal right leg is immobilized in
Above knee synthetic cast.

37. FOLLOW UP
1MONTH
Fibular graft with implant insitu
in tibia.

38. FOLLOW UP
2 MONTHS
Fibular graft insitu.
patient was
allowed partial
weight bearing.

39. LEFT LEG X-RAY
Intact
periosteum of
the fibula
which was
excised and
used as graft.

40. FOLLOWUP
Surgical Incision healed
by primary intension.
Postoperative knee and
ankle movements are
normal
No distal neurovascular
deficit.

41. BIOPSY
biopsy report confirmed the diagnosis of ABC

42. HISTOPATHOLOGY

43. Histopathology
 Large cystic spaces filled with blood and separated by
fibrous septa, alternating with solid areas.
 Cysts and septa lined by fibroblasts, myo-fibroblasts
and histiocytes but not endothelium.
 Clusters of osteoclast-like multi-nucleated giant cells
with loose spindly stroma to cellular stroma, reactive
woven bone.
 Variable mitotic figures and hemosiderin.
 No malignant osteoid, no atypia.

44. DISCUSSION ABC
 Aneurysmal bone cyst is a benign osteolytic bone lesion first
described by Jaffe and Lichtenstein in
1942.
 ABC is a pseudo-tumoral lesion of unknown etiology accounting for
1% of bone tumors.
 They are locally destructive, blood filled lesions.
Demographics:
 75% of patients are < 20 yrs.
 ABC is most common during the second decade of life and
rare in children under 5 years age.
 Ratio of female to male is 2:1.

45. Location
 Most common in metaphysis of long bones.
 Commonly effecting proximal humerus , distal femur and
proximal tibia.
 Most often eccentrically located in the metaphysis.
 Diaphysis involvement is rare.
 Epiphyseal lesions are usually intramedullary and associated
with chondroblastoma or giant cell tumor.
 Spinal lesions account for 12-30% of cases.
 The pelvis accounts for about half of all the flat bones
involved.

46. Location
TIBIA 17.5%
FEMUR 15.9%
VERTEBRA 11%
PELVIS 11%
HUMERUS 9%
FIBULA 7.3%
FOOT 6.3%
HAND 4.7%
ULNA 3.8%
RADIUS 3.1%

47. Pathophysiology
 Primary ABC:
▪ Occurring de-novo , no pre existing lesion.
known to be neoplasms driven by up-regulation
of the ubiquitin-specific protease USP6 ( Tre 2)
gene on 17p13 .
Secondary ABC:
ABC caused by reaction secondary to another bony
lesion.
Account for 20- 30% of ABCs
Not considered a neoplasm because no known
translocation has been identified
◦

48. Associated conditions
ABC is associated with other tumors 30% of
time
Giant cell tumor
Chondroblastoma
Osteoblastoma
Fibrous dysplasia
Chondromyxoid fibroma
Non ossifying fibroma

49. Pathophysiology
Focal vascular malformation with in the
bone, like A-V fistulas, venous blockage
Increased pressure, expansion, erosion,
and resorption of surrounding bone.
Local hemorrhage initiate formation of
reactive osteolytic lesion.

50. Presentation
Symptoms
 pain and swelling
 may present with pathologic fracture in about 8% of cases
Physical examination
 neurologic deficits possible with spine lesions

51. NATURAL HISTORY OF ABC
ABC evolve through 4 radiologic stages:
INITIAL PHASE : well defined area of osteolysis
with elevation of periosteum
GROWTH PHASE: lesion grows rapidly with progressive
destruction of bone. Characteristic BLOWN OUT
appearance
STABILIZATION PHASE: maturation of the bony shell
giving characteristic SOAP BUBBLE appearance
HEALING PHASE: progressive calcification and
ossification of the lesion

52. STAGING
ENNEKING staging of benign lesions
Stage 1 ( latent ) :intra-compartmental, lesion
have well defined cortex
Stage 2 ( active ) : continue to enlarge, lesion
have thinned cortex which may be broken but
limited to the periosteum
Stage 3 ( progressive ) : lesion penetrate the
cortex.

53. CAPANNA ET AL CLASSIFICATION
Based on radiographic findings:
TYPE 1: central metaphysial presentation
TYPE 2: lesion involve the entire segment of bone.
TYPE 3: eccentric metaphysial location
TYPE 4: sub-periosteal extension
TYPE 5: meta-diaphysial location

54. Treatment
Non-operative management
Indications
 ABC with acute fracture
 Indicated until fracture has healed. Once healed,
treat as an ABC without fracture unless the
fracture has led to spontaneous healing of the
ABC

55. Arterial embolisation
Used to treat vascular bone tumors to limit
blood supply at surgery or as definitive therapy
when surgery is not feasible.
Transcatheter arterial embolisation.
Various materials, such as springs and foam,
have been used to create the emboli.

56. Arterial embolisation
ADVANTAGES:
1.Able to reach difficult locations.
2.Save joint function when subchondral bone
destruction is present.
3. Less bleeding during surgery. Performed
within 48 hours before surgery to reduce the
amount of hemorrhage.
4 Non-surgical technique that may be effective
as the primary treatment but, if it fails intervene
surgically .

57. Intralesional Injection
INDICATIONS
1.Surgical access is difficult
2.Other modalities are contraindicated
CONTRAINDICATIONS
1.Patient has allergies to the injection components
2. A pathologic or impeding fracture
3. Neurologic symptoms, or unbearable symptoms such as
pain.
4. Do not use intralesional injection if a better proven
treatment is indicated.
5. Uncertain diagnosis.

58. Intralesional Injection
1.Calcitonin :osteoclastic inhibitory effect and the
trabecular bone-stimulating properties
2. Methyl prednisolone inhibitory angiostatic and
fibroblastic effects
3. ETHIBLOC :mixture of zein, oleum papaveris, and
propylene glycol and acts as a fibrosing agent, and an
inflammatory reaction may occur after its administration.
Bony healing may take months to years.
4.Aqueous solution of calcium sulphate

59. Percutaneous sclerotherapy
using Polidocanol
 Polidocanol was injected into the lesion under fluoroscopic
guidance using a bone-marrow aspiration needle.
 Approximately 1 ml of 3% polidocanol
(Hydroxypolyaethoxydodecan) was injected per 1 cm3 volume
of the lesion.
 No more than 10 ml of sclerosant was injected into any
lesion.
 Complications Local recurrence, induration at the site of
injection, hypopigmentation, local inflammatory reaction, and an
episode of dizziness

60. POLIDOCANOL
Regular followup after injection
End-point of treatment was defined as the time at
which the:
1. Pain had resolved,
2. The cortical thickness of the wall of the cyst had started
reforming
3. Lesion had stopped growing in size.
A second injection of sclerosant was given if any one or a
combination of the above three parameters was not
observed in the first three months after treatment.

61. Surgical Therapy
1. Intralesional curettage.
2. Intralesional excision. The difference
between curettage and excision is that
excision involves wide unroofing of the lesion
through a cortical window by careful abrasion
of all the surfaces with a high-speed burr and,
possibly, local adjuvants.
3.En bloc or wide excision is typically
reserved for ABCs that are not amenable to
intralesional excision

62. Aggressive curettage and bone grafting
Indicated in symptomatic ABC without acute
fracture.
20% recur after curettage, so aggressive
curettage with bone grafting or en bloc
resection is recommended.
If no coexistent lesion is identified ,lesions are
managed by simple curettage and bone
grafting.
If a more aggressive lesion is present,
treatment must be directed toward that
component.

63. Adjuvant therapy
 Extends the area of treatment beyond that which can
be physically excised.
 Adjuvants involve the use of chemical, freezing, or
thermal means to cause bone necrosis and
microvascular damage to the walls of the physically
excised cyst, disrupting the possible etiology.
 Compared with en bloc and regional resection, the use
of adjuvants leaves more bone intact, and an increased
area is treated compared with that treated with
intralesional resection alone.

64. Liquid nitrogen
 Most popular adjuvant
 After the ABC is exposed and a window is opened, liquid
nitrogen may be applied by pouring it into the cyst through a
funnel or by using a machine that is designed to spray the
liquid onto the walls of the lesion.
 A total of 2 or 3 cycles of freezing and thawing should be
used to obtain maximum bone necrosis.
 The surrounding tissue, especially the neurovascular bundles,
must be protected to ensure these structures are not
damaged.
 Avoid the use of a tourniquet with cryotherapy is to keep the
surrounding tissue vascularized, making it more resistant to
freezing.

65. Liquid nitrogen
COMPLICATIONS OF LIQUID NITROGEN
 Gas Embolism
 Late fracture
 Wound necrosis
 Damage to the surrounding tissue (eg,
neurovascular bundles, physis)

66. Phenol
 Less often used as an adjuvant.
 Poor penetration of bony tissue compared
with that of liquid nitrogen.
 Easy to use. Phenol is simply applied to the
mechanically removed walls by using soaked
swabs.
 Any remaining phenol is removed with
suction, and the cavity is filled with absolute
alcohol.
 Finally, the cavity is irrigated with isotonic
sodium chloride solution.

67. PMMA ( BONE CEMENT)
 Thermal properties in causing bone necrosis.
Advantages :
Immediate stability In case of a large lesion.
Easy to recognize a local recurrence.
 If PMMA is used in a subchondral location, the
joint surface should be protected by cancellous
grafts or Gelfoam placed before cementation.

68. Argon beam coagulation
 Surgical treatment with curettage and
adjuvant argon beam coagulation is an
effective treatment option for ABC
 Reducing recurrence
 The primary complication was fracture.

69. MEGAVOLTAGE RADIOTHERAPY
For recurrent tumors, or tumors for which
surgery would result in significant functional
morbidity, radiotherapy (RT) provide a safe
and effective alternative for local control.
Prescribed tumor dose of 25–30 Gy.
CO60 or equivalent megavoltage X-rays are
used.
Produce rapid ossification of the cyst.
Potential for malignant transformation

70. Endoscopic approach to the
treatment of ABC
Minimally
invasive.
Technically
difficult

71. FOLLOW-UP
 Recurrence usually occurs within the first year after surgery,
and almost all episodes occur within 2 years.
 Patients should still be monitored on a regular basis for 5
years.
 It is beneficial to detect recurrence early when the lesion is
still small and easier to treat.
 Children should be monitored until they have reached
maturity to ensure that any possible recurrence does not
cause deformity or interfere with their growth.
 Any patients that have received radiation should be monitored
for life because of the risk of secondary sarcoma.

72. RECURRENCE
.
recurrence
Curettage and bone grafting 10-20%
Curettage and cryotherapy 12.8%
Curettage and irradiation 14.3%
Resection 0%
Radiotherapy 16%
Embolization 10.6%

73. COMPLICATIONS
Universal complications that have been described
with surgery include the following:
• Recurrence
• Blood loss
• Wound infection
• Wound slough
• Wound hematoma
• Osteomyelitis
• Damage to the surrounding tissue
• Possible physis damage
• Pulmonary embolism

74. Outcome and Prognosis
 The prognosis for an ABC is generally excellent, although
some patients need repeated treatments because of
recurrence, which is the most common problem encountered
when treating an ABC.
 The overall cure rate is 90-95%
Increased risk of recurrence.
 1.Younger age,
 2.Open growth plates,
 3.Metaphyseal location of the lesion
The stage of the ABC has not been shown to influence the rate of
recurrence; however, most clinicians believe that stage 3
lesions have the highest recurrence rate.

75. UNTREATED CASES
May involute spontaneously and develop a
heavy shell of reactive bone at periphery. This
involution process is hastened by surgical
curettage and bone grafting.
May lead to pathological fracture.