• A bone tumor, is a neoplastic growth of tissue
in bone. Abnormal growths found in the bone
can be either benign or malignant.
Bones are classified according to their shapeLong bone
Long bone anatomy
Diaphysis: long shaft of bone
Epiphysis: ends of bone
Epiphyseal plate: growth plate
Metaphysis: b/w epiphysis and diaphysis
Articular cartilage: covers epiphysis
Periosteum: bone covering (pain sensitive)
Sharpey’s fibers: periosteum attaches to underlying
• Medullary cavity: Hollow chamber in bone
- red marrow produces blood cells
- yellow marrow is adipose.
• Endosteum: thin layer lining the
• Histology of bone tissue
Cells are surrounded by matrix.
- 25% water
- 25% protein
- 50% mineral salts
4 cell types make up osseous tissue
• Osteoprogenitor cells:
- derived from mesenchyme
- unspecialized stem cells
- undergo mitosis and develop into
- found on inner surface of periosteum
- bone forming cells
- found on surface of bone
- no ability to mitotically
- collagen secretors
- mature bone cells
- derived form osteoblasts
- do not secrete matrix
- cellular duties include
nutrients and waste with
- bone resorbing cells
- bone surface
- growth, maintenance and bone repair
Abundant inorganic mineral salts:
- Tricalcium phosphate in crystalline form called
- Calcium Carbonate: CaCO3
- Magnesium Hydroxide: Mg(OH)2
- Fluoride and Sulfate
• 0.001% of all cancers
• MC benign tumor--- Osteochondroma; Osteoid
• MC Skeletal malignancy– Metastasis.
• MC Bone tumor in Pediatric age group & adultsOsteosarcoma
• MC in < 10 y--- Ewing’s sarcoma
• MC Primary bone tumor – Multiple Myeloma
Patient may present with
An abnormal radiographic finding detected during evaluation of unrelated problem
PAIN:- is most frequent symptom
MASS:- rate of enlargement is important
-Fluctuating mass can be cyst,ganglion or hemangioma
-Family H/O masses near the joint may be indicator of Ollier’s disease or Maffucci
NEUROLOGICAL SYMPTOM:- found in few patients such as sacral tumors & with tumors
located near the nerve causing compression of nerve,especially common in sciatic notch
,inguinal canal & popliteal fossa
UNEXPLAINED SWELLING OF THE LOWER EXTREMITY:- found in pelvic
tumors which are painless & without a palpable mass & cause swelling due to
compression of iliac vein.
• Evaluation of patient’s general health
• TUMOR MASS should be measured & its location,shape,
consistency,mobility,tenderness,local temp & change with
position should be noted.
• SKIN & SUBCUTANEOUS TISSUE :
• Small dialated superficial veins overlying the mass are produced
by large tumors
• Café-au-lait spots & subcutaneous neurofibromas indicate Von
• A venous malformation Maffucci Syndrome
• REGIONAL LYMPH NODES: sign of metastatic disease
• Atrophy of surrounding musculature should be recorded,also
neurological deficits & adequacy of circulation.
HISTORY OF THE PATIENT
• AGE:- most imp information,bcoz of their presentaion in sp age
• 1st decade- usually ABC ,SBC
• 2nd decade-Chondroblastoma,osteosarcoma,Ewings
• 3rd decade- GCT
• 4th decade- chondrosarcoma
• 5th decade- Multiple myeloma
• SEX:- less imp than age
• RACE:- little imp, Ewings rare in african descent
• H/O any exposure to radiation Tt or Carcinogens- bone seeking
radionucleotide can cause sarcoma.
• Various chemical carcinogens- zinc beryllium silicate, beryllium oxide.
• Currently the most worrisome & controversial is Nickel which is used
in many orthopedic devices.
TECHNETIUM BONE SCAN-This type of scan uses a
very low radioactive material (diphosphonate) to see
whether or not the cancer has spread to other
bones and the damage suffered by the bone.
• PET- uses radioactive glucose to locate cancer. This
glucose contains a radioactive atom that is absorbed
by the cancerous cells and then detected by a special
• The biopsy is the most conclusive test because it confirms if
the tumor is malignant or benign, the bone cancer type
(primary or secondary bone cancer), and stage.
• According to the tumor size and type (malignant or benign)
and the biopsy's purpose (to remove the entire tumor or only a
small tissue sample), there are two types of biopsies used in
bone cancer diagnosis. These are: needle biopsy and incisional
• 1. Needle biopsy: During this procedure, a small hole is made
in the affected bone and a tissue sample from the tumor is
• There are two types of needle biopsies:
• Fine needle aspiration: During this procedure, the tissue
sample is removed with a thin needle attached to a syringe.
• Core needle aspiration: During this procedure, the surgeon
removes a small cylinder of tissue sample from the tumor with
a rotating knife like device.
• 2. Incisional biopsy: During this procedure, the surgeon cuts
into the tumor and removes a tissue sample.
Figure 2: The lesion consists of dense and lamellar cortical
bone with a focal area of active bone modeling.
Figure 3: Photomicrograph of the more solid area of the
lesion to demonstrate the cellular woven character of the
• Pain, characteristically more intense at night, relieved by NSAID
and eliminated by excision
• 10-30 years
• M > F (2:1)
• Anatomic Distribution:
• Nearly every location, most frequent in femur, tibia,( Over 50%)
humerus, bones of hands and feet, vertebrae and fibula
• Metaphysis / Diaphysis (cortical) of long bones
• Vertebral lesions may be associated with scoliosis.
Small central osteolytic nidus surrounded by dense
The small, reddish central nidus is surrounded by a thick layer
of sclerotic bone
New osteoid and bone formation by plump osteoblasts.
The stroma is cellular and well vascularized
Osteoid osteoma with anastomosing trabeculae of
• Also called as Giant osteoid osteoma.
• Osteoblastoma is similar to osteoid osteoma with
more aggressive behavior.
• D/D from osteoid osteoma*Pain
*Absence of reactive bone
* Large size
• Location :
– In spine or major bones of lower extremity
Well differentiated radiopaque/radiolucent lesion
Osteoblastoma.-The histologic appearance is identical
to that of osteoid osteoma.
Recurrent osteoblastoma.-The appearance is similar to
that of osteoid osteoma
Tumor is located at the typical metaphyseal site. The tumor
shown in A is largely restricted to bone, whereas that illustrated
in B is accompanied by massive soft tissue extension.
‘skip metastasis’ located in the upper half of the femur. The
primary tumor was located in the lower metaphysis of the same
The malignant bone is more basophilic and has more
irregular borders than the preexisting bone
Osteosarcoma showing characteristic basophilic thin
trabeculae of neoplastic bone with an appearance that
is reminiscent of fungal hyphae
Lace-like osteoid deposition is very
characteristic of this neoplasm.
Osteoblastic osteosarcoma with finely ramifying matrix
between tumor cells
• Blood filled cystic space and thus
radiologically appears as pure lytic lesion.
• Pathological fractures.
• Grossly the lesion simulate aneurysmal
• Detection of malignant stroma in the septa
that separate the bloody cysts.
Well differentiated intramedullary
.This tumor is microscopically so bland looking as to be often
underdiagnosed as a benign lesion.
In contrast to fibrous dysplasia
1- this tumor shows radiographic evidence of cortical
2-Microscopically, atypia is minimal but still present.
3-The invasive growth pattern.
Variants defined on the basis of topographic,
clinical and radiographic features:
• Slightly older age group
• Juxtacortical position in the metaphysis of
of upper femur. There is only
minimal involvement of the
large extracortical component
Juxtacortical osteosarcoma--Moderately atypical spindle tumor cells
grow between irregularly shaped bone trabeculae
Parosteal osteosarcoma-The spindle cells demonstrate
minimal atypia, and the bone appears to arise directly from
the spindle cells.
• Grows on surface of long bones.
• Upper tibial shaft or femur.
Periosteal osteosarcoma. The white shining appearance
is due to the high content of cartilage
periosteal chondrosarcoma. There is a predominance of
Bone formation in the center of a cartilaginous lobule
in periosteal osteosarcoma
Osteosarcoma of jaw:
• Patients affected are slightly older (average age, 34
• And most lesions show a prominent chondroblastic
• The most common sites of involvement are the body
of the mandible and the alveolar ridge of the maxilla.
Osteosarcoma in Paget’s disease.
• Osteosarcoma are of the polyostotic type
• Pelvis, humerus, femur tibia & skull.
• Large number of osteoclasts alternating with atypical
• Benign tumor of mature hyaline cartilage
• Age – 20-50 yrs
• Usually solitary,30% are multiple.
• Bones involved: small bones of hand & feet.
• Asymptomatic, pain & swelling.
Enchondroma is the most common tumor of
the bones of the hand
• Begin in spongiosa of diaphysis, from which they expand
and thin cortex
• Unusual in ribs and long bones
• Much less common than enchondroma
• Involve parosteal region of long bone or small bone of
hand or foot
2 syndromes characterized by multiple
• Ollier’s disease
• Maffucci’s syndrome
• Both disorders have 25% risk of malignant transformation to
Maffucci syndrome-Innumerable chondromas are seen
concentrated in the distal aspect of the extremity
Juxta-cortical - The tumor produces a
semispherical expansion of the involved bone.
Enchondroma-The tumor has a typical
Also known as exostosis.
Most frequent benign cartilaginous tumour.
Age/sex - <20yr, M:F=3:1
Bones involved: lower femur, upper tibia,
upper humerus and pelvis.
• Location: Metaphysis
• Probably not a true neoplasm.
• Inactivation of both copies of the EXT gene in
the growth plate chondrocytes.
• Presents as slow growing mass, painful.
• <1% cases show malignant transformation.
A- Large osteochondroma of femur with a bilobed appearance.
B Cut surface of osteochondroma of ribthick cartilaginous cup
Projection with cortex continuous with underlying bone;
may be pedunculated; cartilaginous cap with frequent
Microscopic-Mature bone is covered by a welldifferentiated cartilaginous cap.
Chondroblastoma with eosinophilic chondroid matrix,
giant cells, and mononuclear cells
Imagine the cells present without the nuclei: The thickened cell membranes
would give a chicken wire fence appearance
• Benign tumour of cartilaginous origin.
• Age/Sex: 20-30 yr/ M:F=2:1
• Bones involved: Long bones>flat bones
• Location: Metaphysis.
• Localised pain with or without tenderness
Sharply delimited chondromyxoid fibroma of lower
femoral metaphysis in a young boy.
A-Chondromyxoid fibroma of proximal femur extending into
B-The tumor has a lobulated appearance, in which
myxochondroid islands alternate with more cellular foci.
Chondromyxoid fibroma- (A) An irregularly shaped
hypocellular center is surrounded by a cellular spindle
(B) The lobules contain tumor cells with small nuclei
and eosinophilic cytoplasmic extensions within a
• Second most common malignant tumour of bones.
• Arise de novo or from pre-existing benign
• Divided into two major categories:
• 30 – 60 yr of age.
• Divided according to location:
Typical chondrosarcoma of femurI-ill defined margins;
fusiform thickening of shaft; perforation of cortex
• Tumour is present on the surface of bone.
• May arise de-novo or from cartilaginous cap
of preexisting osteochondroma.
Peripheral chondrosarcoma of femur resulting in a huge
– shaft of long bone (most often femur)
• Cartilaginous lobular pattern with areas of:
– spotty calcification
– endochondral ossification
• Closely related to periosteal osteosarcoma.
• Wide range of differentiation and graded into:
– well differentiated
– moderately differentiated
– poorly differentiated
Well-differentiated chondrosarcoma. The tumor has a
distinctly lobulated quality
Well differentiated- High-power appearance of grade 1
chondrosarcoma. A few doubly nucleated cells and
moderate atypia .
Moderately differentiated - High-power
appearance of grade 2 chondrosarcoma with necrosis .
The nuclei are crowded and hyperchromatic
• Grade I : lesions contain hyaline cartilage manifested by
sparse cellularity. The cells typically contain dark, pyknotic
nuclei. <20% of cells contain large nuclei and fine nuclear
chromatin. Mitosis is absent.
• Grade II: A) lesion are slightly more cellular and >20% nuclei
are larger than nucleus of mature lymphocyte. Binucleate
cells are easily found. Mitosis is absent.
B) cellular lesions with numerous binucleated cells and
nuclear atypia. Mitosis is present but not more than
• Grade III: Mitosis atleast >=2 / 10 hpf
• The main differential is of low grade (Grade 1)
chondrosarcoma and enchondroma.
• Features consistent with chondrosarcoma are:
*Pain attributable to lesion
*Age greater than 50
*Cortical destruction and a soft tissue mass
*Periosteal reaction and thickening
*Endosteal erosion>2/3 cortical thickness on a CT scan
*Size greater than 5 cm
• Worst prognosis.
• Age/sex: sixth decade/ M:F =1:1.
• Bones involved: pelvis, femur.
• Poorly differentiated sarcomatous component
at periphery of otherwise typical low-grade
– usually central type
– can be peripheral
Gross appearance of dedifferentiated
chondrosarcoma of pelvic bone -
– may be in initial lesion
– more often in specimens from recurrent tumor:
• microscopic appearance of this component may be:
pleomorphic sarcoma with MFH-like features
The edge of an island of well-differentiated cartilage (upper left) is
surrounded by highly pleomorphic sarcoma containing tumor giant
Chondrosarcoma is juxtaposed with high-grade
malignant fibrous histiocytoma
Clear cell variant:
• Behaves as low-grade malignancy
• Can undergo dedifferentiation
• Age/Sex : 30-40 yrs/M:F= 2.5:1
• Location: proximal end of femur and humerus.
Clear cell chondrosarcoma with faint lobulation, woven
bone, and clear cells
• Usually second or third decade of life
• Great variability in clinical course.
– most commonly:
Shows an island of well-differentiated cartilage in the
SALIENT PATHOLOGIC FINDING
MINERALIZED COMPACT BONE
CORTEX OF 10-30/2:1
IS OF LB
“NIDUS” OF IMMATURE BONE SURROUNDED BY
IDENTICAL TO OSTEOID OSTEOMA BUT LARGER AND
OFTEN NO SCLEROSIS
-OSTEOID FORMED DIRECTLY BY MALIGNAT CELLS
-B- MILDLY ATYPICAL FIBROBLASTIC
PROLIFERATION+THICK BONE TRABECULAE