Common benign and malignant bone tumors

1. Manal Ismail Abd-Elghany
Associate Professor of Pathology, PhD (UK),
MD(Egypt)
Musculo-skeletal System Part II
Bone Tumors

2.  I. According to histological origin:
 A. Osseous tumours
 B. Non-Osseous tumours
 II. According to their Behavior:
 A. Benign
 B. Locally malignant
 C. Malignant
Classification of Primary Bone Tumours

3. Histological
derivation (origin) Benign Locally
Malignant
Malignant
A. Osseous tumours
I. Bone-forming (osteogenic,
ostaoblaslic) tumours
o Osteoma
o Osteoid osteoma
o Osteoblastoma
- o Osteosarcoma
II. Cartilage-forming
(chondrogenic) tumours
o Enchondroma
o Osteochondroma
o Chondroblastoma
o Chondromyxoid
fibroma
- o Chondrosarcoma
III. Haematopoietic (marrow)
tumours
- - o Myeloma
o Lymphoma
IV. Unknown - o Giant cell tumor o Malignant giant cell
tumour
o Ewing's sarcoma
V. Notochordal tumour - - o Chordoma
VI. Epithelial - o Adamantinoma o Malignant
Adamantinoma
Classification of Primary Bone Tumours
1

4. Malignant
Locally
malignant
Benign
Histological
origin
B. NON-OSSEOUS TUMOURS
o Haemangiopericytoma
o Angiosarcoma
-
o Haemangioma
I. Vascular tumours
o Fibrosarcoma
-
o Non-ossifying
fibroma
II. Fibrogenic tumours
o Neurofibrosarcoma
o Malignant
Schwannoma
-
o Neurofibroma
o Schwannoma
III. Naurogenic tumours
o Liposarcoma
-
o Lipoma
IV. Lipogenic tumours
o Malignant fibrous
histiocytoma
-
o Fibrous
histiocytoma
V. Histiocytic tumours
2
Classification of Primary Bone Tumours continued

5. Benign Bone Tumours
 Examples of benign bone tumours include:
 Osteoma
 Chondroma & Enchondroma
 Osteochondroma (Exostosis)
 Chondroma & Enchondroma
 In each tumour, the followings will be discussed:
 Histological Origin:
 Site:
 Gross picture:
 Microscopic picture:

6. Osteoma
 Origin: It is a benign tumour arising from bone.
 Site: It arises from membranous bones of skull.
 Gross picture: A hard sessile mass which is
not capsulated.
 Microscopic picture:
 The lesion is composed of well-differentiated
mature lamellar bony trabeculae separated by
fibro-vascular stroma.
3

7. Gross Picture of Osteoma
It appears as a hard sessile mass which is not capsulated.

8. Microscopic Picture of Osteoma
The lesion is composed of well-differentiated mature lamellar bony trabeculae
separated by fibro-vascular stroma.
Mature bony trabeculae
Stroma.

9. Osteoid Osteoma
 Origin: It’s a benign tumour arising from bone.
 Site: The cortex of long bones e.g. femur & tibia.
 Gross picture:
 It’s generally small (usually less than 1 cm) and
painful tumour.
 The tumour is clearly demarcated.
 Microscopic picture:
It’s composed of the following:
 Central Nidus: Contains dilated blood vessels,
osteoid, woven bone & osteoblasts .
 Surrounding fibrovascular rim & reactive new bone
formation.
4

10. Gross Picture of Osteoid Osteoma
 The tumour ’s generally small (usually <1 cm), painful & is
clearly demarcated.

11. Gross Picture of Osteoid Osteoma

12. Microscopic Picture of Osteoid Osteoma
Central
Nidus
Fibrovascular rim & reactive new bone formation

13. Osteochondromas
(Exostoses)
 Origin:
 They are the commonest benign cartilage-
forming lesions. N.B. They may undergo
transformation into chondrosarcoma.
 Site:
 The tumour arises from metaphysis of long
bones as exophytic lesions, so they’re called
exostoses.
 They affect most commonly lower femur and
upper tibia (i.e. around knee joint) and upper
humerus. 5

14.  Gross picture:
 Osteochondromas are mushroom-like
exophytic lesions (i.e. protrude over the surface)
with outer cartilage cap and inner well-formed
cortical bone and marrow.
6

15.  Microscopic picture:
 The lesion is composed of outer mature
cartilage (cap) and inner mature lamellar
bone & marrow.
7
Cortical bone &
marrow
Cartilage Cap

16. Chondroma & Enchondroma
 Origin:
 Chondroma is a benign tumour arising from
cartilage and is located peripherally.
 Enchondroma develops centrally within the
interior of the affected bone. It may develop
into chondrosarcoma.
 Site:
 Enchondromas most commonly involve short
bones of the hands and feet, and less
commonly the ribs or long bones.
8

17.  Gross picture:
 Enchondroma is
lobulated, bluish-
gray, translucent,
cartilaginous mass
lying within the
medullary cavity.
9

18.  Microscopic
picture:
 The tumour has
characteristic
lobulated
appearance.
 The lobules are
composed of
normal adult
hyaline cartilage
separated by
vascularized
fibrous stroma.
10

19. Locally Malignant Tumours
 Example of locally-malignant bone tumours includes:
 Giant cell tumor/Osteoclastoma
 The followings will be discussed:
 Behavior:
 Origin:
 Age:
 Gender/sex:
 Sites:
 Gross picture:
 Microscopic picture:

20. Giant cell tumor of bone “Osteoclastoma”
 Behavior: Locally malignant (Mostly),
however few (10%-20%) are malignant
and metastasize.
 Origin: ? uncertain
 Age: usually between the age of 20-40ys.
 Gender/sex: No special link.
 Sites: Most commonly around the knee
joint. It involves the epiphysis of long
bones. 11

21.  Grossly:
 It is partially cystic, large,
eccentric lesion in the
epiphysis of long bone.
 It shows areas of
hemorrhage.
 It’s characterized by egg-
shell like cracking feature
due to thinning of cortex.
12

22.  Microscopically:
The tumour consists of:
1. Multinucleated giant cells
(which are non-
neoplastic). They are
considered the hallmark of
giant cell tumour.
2. Mononuclear stromal
cells (which are the
neoplastic component of
the tumour).
3. Other features of the
stroma: such as scanty
collagen, rich vascularity &
macrophages.
13

23. Osteoclastoma

24. Malignant Tumours
 Examples of malignant tumours include:
 Osteosarcoma
 Chondrosarcoma
 In each tumour, the followings will be discussed:
 Origin & Behavior:
 Age:
 Gender/sex:
 Sites:
 Gross picture:
 Microscopic picture:
 The tumour is characterized by:
 Predisposing factors:

25. Osteosarcoma
 Origin & Behavior: It’s the commonest & most malignant bone
tumour. The tumour is thought to arise from primitive osteoblast-forming
mesenchymal cells.
 Age: Children & young adults, usually below 20 years.
 The tumour is characterized by: formation of osteoid, bone, or both by
sarcoma cells.
 Predisposing factors:
1. Trauma
2. Irradiation
3. Osteochondroma
4. Paget’s disease of bone
5. Fibrous dysplasia
 Sites: The tumour arises in the metaphysis of long bones.
 1. Most common sites:
A. The lower end of Femur, upper end of tibia i.e. around knee joint
(about 60%)
B. Pelvis and the upper end of femur (about 15%)
C. The upper end of humorus (about10%).
 2. Less often in jaw bones, vertebrae and skull.
14

26.  Grossly:
 The tumour:
It forms a large
mass that extends
within the medullary
cavity & destroys the
bone matrix.
 The periosteum:
It is elevated then
becomes invaded
 Adjacent soft
tissues is infiltrated
by the tumour.
spreads to the.
 Hemorrhage &
necrosis is
frequently marked.
15
Note a large, infiltrative lesion situated within the
metaphysis. The tumour destroyed the bony
cortex, extended inward into the bone marrow and
outward into the adjacent soft tissue.
Gross picture of a case of osteosarcoma

27.  Microscopically:
1. Sarcoma cells have
marked pleomorphism.
2. Osteoid deposition
as a an anastomosing
network of delicate
trabeculae. Some
osteoid is mineralized
(new bone formation).
16
Microscopic picture of a case of
osteosarcoma

28. Microscopic picture of osteosarcoma

29. Microscopic picture of a case of osteosarcoma
Osteoid
Mineralized Osteoid

30. Chondrosarcoma
 Origin & behavior: Chondrosarcoma is a malignant tumour
arising from chondroblasts.
 Age: Chondrosarcoma usually occurs in patients between
3rd and 6th decades of life.
 Sex/gender: There’s slight male predominance.
 Predisposing factors:
1. Paget’s disease of bone
2. Fibrous dysplasia
3. Chondroma and osteochondroma
 Sites:
 The majority are found in the central skeleton (i.e. in
the pelvis, ribs and shoulders)
 The rest occurs around the knee joint.
17

31.  Grossly:
 Chondrosarcoma may vary in
size from a few centimeters to
extremely large and lobulated
masses of firm consistency.
 Cut section shows
translucent, bluish-white &
gelatinous appearance with
foci of calcification.
18

32. Chondrosarcoma

33. Chondrosarcoma

34. 34
Chondrosarcoma
B
Microscopic (A) and gross (B)
Pathological features of a case of
Chondrosarcoma.

35.  Microscopically:
 The hallmark of
chondrosarcoma is the
invasive character &
formation of lobules of
malignant cartilage cells
showing cytologic features
of malignancy.
 The malignant cells are
present within a hyaline
matrix.
 Spotty calcification is
common.
19

36. 36
Chondrosarcoma
Normal cartilage.

37. 37
Chondrosarcoma
b
A. Cut section shows infiltrating
chondrosarcoma into the marrow.
B. Higher power view of the previous
image showing atypical
chondrocytes in a Grade I
chondrosarcoma. Plump
hyperchromatic nuclei with
prominent nucleoli and binucleated
cells are occasionally seen.
Normal cartilage.

38. Quiz
A B
A. Microscopic picture of ……….., which shows ……………………………
B. Cut section shows ……………..