Extraskeletal Osteosarcoma.
Full Papper Case Report
Extraskeletal Osteosarcoma
dr Nyoman Gde Aditya Gitapradita B
dr Gede Eka Wiratnaya SpOT
Department Of Orthopaedic and Traumatology
Udayana University/Sanglah Hospital
February 2015
EXTRASKELETAL OSTEOSARCOMA
INTRODUCTION
Estraskeletal osteosarcoma is malignant mesenchymal neoplasm that produces
osteoid, bone or chondroid material without demonstrable attachment to bone or periosteum,
as determined by radiographic and intraoperative examination. The diagnosis of extraskeletal
osteosarcoma is very rare and represent 2% to 5% of osteosarcoma and < 1% of all soft tissue
sarcomas. Males are affected more frequently than females. 1,2,4
Previous prospective studies follow of soft tissue sarcoma have not analyzed
extraskeletal osteosarcoma separately, as the number of cases remains small. Most common
location is lower extremity especially in thigh, followed by upper extremity and
retroperitoneum mechanical injury has been hipothesized as causative agent, but the etiologic
eignificance of trauma is difficult to assess. 2,3
CASE AND METHOD
Male, 14 years old with chief complained lump on left thigh since 10 month prior to
admission. Lump getting bigger gradually since 6 month prior to admission. Theere was no
pain on his lump. History of trauma is negative and he can walk normally. From physical
examination therewas mass on medial side of proximal left femur without venectasis and
hyperemia, skin contour is normal. Solid mass 20 x 15 cm with ill define margin without
tenderness. AVN distal is normal. Active ROM of Hip and Knee is normal. From x ray pelvis
AP and x ray left femur AP/lateral we foundd soft tissue mass (extraskeletal mass) with
calsification without connectivity to cortex of medial side os femur. Patient already done
open biopsy in another hospital 10 month prior to admission with result heterotropic
ossificans. MSCT angiography of left femur showed bulging solid soft tissue mass
intramuscular on left proximal femur with calsification and ill define margin, without
destruction to os femur and os pelvis, and no periosteal reaction, conclusion suspected to
myositis ossificans dd/ parosteal osteosarcoma. MRI left femur with contrast showed soft
tissue mass with ill defined margin with size 13.7 x 11.1 x 14.9 cm inside of medial muscle
of femur (m. vastus medial, m. adductor longus – brevis, m. sartorius), that view
isohypointens on T1WI, hyperintens on T2WI and T2 FS, with vassa femoralis pushed to
lateral without encasement vassa femoralis. The soft tissue mass without extend to subcutis.
Os femur without destruction cortex or bone marrow intensity changes. We perform marginal
excisssion and biopsy. The Result of histophatology is extraskeletal osteosarcoma.
Picture 1. Solid mass on medial side proximal left thigh
Picture 2. X ray pelvis AP and Femur AP, soft tissue mass (extraskeletal mass) with
calsification without connectivity to cortex of medial side os femur
Picture 3. MSCT Angiography left femur, bulging solid soft tissue mass intramuscular on
left proximal femur with calsification and ill define margin, without destruction to os femur
and os pelvis, and no periosteal reaction
Picture 4. MRI with contrast left femur, soft tissue mass with ill defined margin with size
13.7 x 11.1 x 14.9 cm inside of medial muscle of femur (m. vastus medial, m. adductor
longus – brevis, m. sartorius), that view isohypointens on T1WI, hyperintens on T2WI and
T2 FS, with vassa femoralis pushed to lateral without encasement vassa femoralis. The soft
tissue mass without extend to subcutis. Os femur without destruction cortex or bone marrow
intensity changes
Picture 5. Clinical Picture post marginal excision and biopsy
Picture 6. Clinical picture of solid mass, red arrow is bone or condroid matrial
Picture 7. Show that mass of the tumor infiltration inside bone trabeculae
Picture 8. Show that cell condrosit atipic
DISCUSSION
Extraskeletal osteosarcoma (EO) is a malignant mesenchymal tumour of soft tissue
composed of neoplastic cells that recapitulate the phenotype of osteoblasts and synthesize
bone. all EOs contain neoplastic bone but may also have cartilaginous and fibroblastic
components. By the definition, extraskeletal osteosarcoma arises from soft tissue without
osseous or periosteal involvement. 4, 5
Extraskeletal osteosarcoma is a rare neoplasm that accounts for 1-2% of all soft tissue
sarcomas and approximately 2- 4% of all osteosarcomas. It typically arises during mid and
late adulthood with most patients in the 5th-7th decades of life at the time of diagnosis. Males
are affected more frequently than females at a ratio of 1.9:1. 4
The majority of EOs arise in the deep soft tissues and fewer than 10% are superficial,
originating in the dermis or subcutis. The single most common location is the thigh
(approximately 50% of cases); other frequent sites include the buttock shoulder girdle, trunk,
and retroperitoneum. 4
EO first described by Wilson in 1941, few large series of these tumors have been
reported. In 1956, Fine and Stout suggested that it may show behavior similar to primary
osteogeneic osteosarcoma in the bone. As compared with osteosarcoma of bone, EOs is rare
and occurs infrequently in patients under 40 years age. 2,6,7
Most patients present with a progressively enlarging mass that maybe associated with
pain. By definition these tumours do not arise from bone, but may secondarily involve the
periosteum, cortex or medullary canal. To be qualified as extraskeletal osteosarcoma, the
tumor must (1) arise in the soft tissue and not be attached to bone or periosteum, (2) have a
uniform sarcomatous pattern (to exclude the possibility of mixed malignant mesenchymal
tumor), and (3) produce osteoid and/or cartilage matrix. 4,6
Plain radiographs, CT and MRI usually reveal a large deep-seated soft tissue mass
with variable mineralization. On radiograph, extraskeletal osteosarcoma often appears as soft
tissue opacity with variable amount of mineralization. Calcification or osteoid matrix
formation is present in approximately 50% of primary lesion. On CT, the tumor separate from
adjacent ossous structures and appears to have pseudocapsule. Matrix mineralization is best
appreaciated on CT rather than radiograph or MRI. On MRI, the tumor is usually a relatively
well circumscribed heterogenous mass, which isointense to skeletal muscle on T1 weighted
sequences and isointense to mildly hyperintense relative to skeletal muscle on T2 weightted
sequences. The presence of hemorrhage is not rare and may be represented by hyperintense
foci on T1-T2 weighted sequences, consistent with methmoglobin, or hypointense foci on T2
weighted sequence, consistent with hemosiderrin deposition. 7
Extraskeletal osteosarcomas range in size from 1-50 cm (mean 8-10 cm) and are
circumscribed, tan-white, haemorrhagic and focally necrotic gritty masses. All of the major
subtypes of osteosarcoma that arise in bone may be seen in EO. The most common is the
osteoblastic variant, followed by the fibroblastic, chondroid, telangiectatic, small cell, and
well differentiated types. The tumour cells are spindle or polyhedral cells that are
cytologically atypical, are mitotically active and frequently demonstrate atypical mitotic
figures. The bone is usually most prominent in the centre of the tumour with the more
densely cellular areas located in the periphery a pattern that is the reverse of myositis
ossificans. Telangiectatic EOs contain numerous large blood filled spaces lined by malignant
cells. Sheets of small round cells that mimic Ewing sarcoma or lymphoma are typical of the
small cell variant. The extremely rare well differentiated subtype contains abundant bone
deposited in well formed trabeculae, surrounded by a minimally atypical spindle cell
component similar to parosteal osteosarcoma. 7
Extraskeletal osteosarcoma, similar to its bone counterpart, was charactheristic by
fully malignant, anaplastic spindle cell proliferation, with the presence of osteoid matrix or
immature bone formed by neoplastic cell. Malignant condroid areas also observed in
association with osteoid or bone component. Occasionally, extraskeletal osteosarcoma has
been mistaken for myositis ossificans. Extraskeletal osteosarcoma can be difficult to
distinguish from MFH, Fibrosarcoma and malignant schwanoma. The pathologic diagnosis
is confirmed by the presence of neoplastic osteoid, with or without cartilage matrix, produced
by the malignant mesenchymal cells, identical morphologically to primary osteogenic
sarcoma of the bone. 2,5,6
Recommended treatment has primarily been surgical. The surgical treatment reported
in the literature has involved intralesional excision, marginal excision, wide excision, radical
excision as an initial operation with or without adjuvant radiation depending on the overall of
the lesion. Radical resections are effective for local control and have the best change of cure
the lungs are the most common site for metastasis (80% of cases) and resection of metastasis
can occasionally achieve a cure. However, chemotherapy and radiotherapy may be useful in
an aggressive multimodality approach to this tumor. Adjuvant radiation and chemotherapy
are considered for high risk lesion (high grade, large) and for incomplete resections. Adjuvant
radiation therapy decreases local recurrences in soft tissue sarcomas, however, most studies
regarding radiation and soft tissue sarcomas do not include cases of extraskeletal
osteosarcoma, if specified at all. 1,5,6
Extraskeletal osteosarcoma has a very poor prognosis and approximately 75% of
patients die of disease within 5 years of diagnosis. More than half of the patient have multiple
recurrences and metastasis. Most local recurrences and distant metastases occur within 3
years postoperatively. Lee and colleagues, found no association between size and
survivability. Therefore, a classification system that guides treatment on basis of prognostic
factors is as yet unefined. Nevertheless, as metastasis is the main factor in survival rate, early
diagnosis is imperative. 4,5,6
CONCLUSION
Extraskeletal osteosarcoma is a rare neoplasm that accounts for 1-2% of all soft tissue
sarcomas and approximately 2- 4% of all osteosarcomas. Classification system that guides
treatment on basis of prognostic factors is as yet undefined. Nevertheless, as metastasis is the
main factor in survival rate, early diagnosis is imperative
Refferences
1. Lisa E. Choi, MD et al. Analysis of Outcomes in Extraskeletal Osteosarcoma: A Review of
Fifty-three Cases. Memorial Sloam-Kettering Cancer Center, New York, NY. Journal Bone
Joint Surgery. 2014; 96: e2 (1-8)
2. Martin D. McCarter et al. Extraskeletal Osteosarcoma: Analysis of Outcome Of Rare
Neoplasm. Memorial Sloam-Kettering Cancer Center, New York, NY. Sarcoma.2000. 4,
119-123
3. Fouzia Lateef et al. Extraskeletal Osteosarcoma. Departement of Hystophatology. Dr.
Ziauddin Hospital, Karachi. Journal of the Collage of Physician and Surgeon Pakistan. 2011.
Vol. 21 (7): 429-430
4. Christhoper D.M. Fletcher et al. Pathology and Genetics of Tumours of Soft Tissue and
Bone. WHO. IARCPress. Lyon. 2002
5. Brian E. Welczak et al. Rare Extraskeletal Osteosarcoma in the Anterolateral Right Leg of
a 37-Year-Old Man. Department Orthopaedic Surgery, Mount Clemens Regional Medical
Centre, Michigan. Am J Orthop. 2009; 38(5): E93-E97
6. Joy S.Y.Lee, M.D et al. A Review of 40 Patients With Extraskeletal Osteosarcoma.
Division Anathomic Pathology and the Department of Orthopaedic, Mayo Clinic and Mayo
Foundation, Rochester, Minesota. 1995
7. Grainne Mc Auley et al. Extraskeletal Osteosarcoma: Spectrum of Imaging Findings.
Department of Radiology, Dana Ferber Cancer Institute, Havard Medical School, 450
Broklyn Ave, Boston. MA. AJR 2012; 198:W31-W37
Extraskeletal Osteosarcoma
dr Nyoman Gde Aditya Gitapradita B
dr Gede Eka Wiratnaya SpOT
Department Of Orthopaedic and Traumatology
Udayana University/Sanglah Hospital
February 2015
EXTRASKELETAL OSTEOSARCOMA
INTRODUCTION
Estraskeletal osteosarcoma is malignant mesenchymal neoplasm that produces
osteoid, bone or chondroid material without demonstrable attachment to bone or periosteum,
as determined by radiographic and intraoperative examination. The diagnosis of extraskeletal
osteosarcoma is very rare and represent 2% to 5% of osteosarcoma and < 1% of all soft tissue
sarcomas. Males are affected more frequently than females. 1,2,4
Previous prospective studies follow of soft tissue sarcoma have not analyzed
extraskeletal osteosarcoma separately, as the number of cases remains small. Most common
location is lower extremity especially in thigh, followed by upper extremity and
retroperitoneum mechanical injury has been hipothesized as causative agent, but the etiologic
eignificance of trauma is difficult to assess. 2,3
CASE AND METHOD
Male, 14 years old with chief complained lump on left thigh since 10 month prior to
admission. Lump getting bigger gradually since 6 month prior to admission. Theere was no
pain on his lump. History of trauma is negative and he can walk normally. From physical
examination therewas mass on medial side of proximal left femur without venectasis and
hyperemia, skin contour is normal. Solid mass 20 x 15 cm with ill define margin without
tenderness. AVN distal is normal. Active ROM of Hip and Knee is normal. From x ray pelvis
AP and x ray left femur AP/lateral we foundd soft tissue mass (extraskeletal mass) with
calsification without connectivity to cortex of medial side os femur. Patient already done
open biopsy in another hospital 10 month prior to admission with result heterotropic
ossificans. MSCT angiography of left femur showed bulging solid soft tissue mass
intramuscular on left proximal femur with calsification and ill define margin, without
destruction to os femur and os pelvis, and no periosteal reaction, conclusion suspected to
myositis ossificans dd/ parosteal osteosarcoma. MRI left femur with contrast showed soft
tissue mass with ill defined margin with size 13.7 x 11.1 x 14.9 cm inside of medial muscle
of femur (m. vastus medial, m. adductor longus – brevis, m. sartorius), that view
isohypointens on T1WI, hyperintens on T2WI and T2 FS, with vassa femoralis pushed to
lateral without encasement vassa femoralis. The soft tissue mass without extend to subcutis.
Os femur without destruction cortex or bone marrow intensity changes. We perform marginal
excisssion and biopsy. The Result of histophatology is extraskeletal osteosarcoma.
Picture 1. Solid mass on medial side proximal left thigh
Picture 2. X ray pelvis AP and Femur AP, soft tissue mass (extraskeletal mass) with
calsification without connectivity to cortex of medial side os femur
Picture 3. MSCT Angiography left femur, bulging solid soft tissue mass intramuscular on
left proximal femur with calsification and ill define margin, without destruction to os femur
and os pelvis, and no periosteal reaction
Picture 4. MRI with contrast left femur, soft tissue mass with ill defined margin with size
13.7 x 11.1 x 14.9 cm inside of medial muscle of femur (m. vastus medial, m. adductor
longus – brevis, m. sartorius), that view isohypointens on T1WI, hyperintens on T2WI and
T2 FS, with vassa femoralis pushed to lateral without encasement vassa femoralis. The soft
tissue mass without extend to subcutis. Os femur without destruction cortex or bone marrow
intensity changes
Picture 5. Clinical Picture post marginal excision and biopsy
Picture 6. Clinical picture of solid mass, red arrow is bone or condroid matrial
Picture 7. Show that mass of the tumor infiltration inside bone trabeculae
Picture 8. Show that cell condrosit atipic
DISCUSSION
Extraskeletal osteosarcoma (EO) is a malignant mesenchymal tumour of soft tissue
composed of neoplastic cells that recapitulate the phenotype of osteoblasts and synthesize
bone. all EOs contain neoplastic bone but may also have cartilaginous and fibroblastic
components. By the definition, extraskeletal osteosarcoma arises from soft tissue without
osseous or periosteal involvement. 4, 5
Extraskeletal osteosarcoma is a rare neoplasm that accounts for 1-2% of all soft tissue
sarcomas and approximately 2- 4% of all osteosarcomas. It typically arises during mid and
late adulthood with most patients in the 5th-7th decades of life at the time of diagnosis. Males
are affected more frequently than females at a ratio of 1.9:1. 4
The majority of EOs arise in the deep soft tissues and fewer than 10% are superficial,
originating in the dermis or subcutis. The single most common location is the thigh
(approximately 50% of cases); other frequent sites include the buttock shoulder girdle, trunk,
and retroperitoneum. 4
EO first described by Wilson in 1941, few large series of these tumors have been
reported. In 1956, Fine and Stout suggested that it may show behavior similar to primary
osteogeneic osteosarcoma in the bone. As compared with osteosarcoma of bone, EOs is rare
and occurs infrequently in patients under 40 years age. 2,6,7
Most patients present with a progressively enlarging mass that maybe associated with
pain. By definition these tumours do not arise from bone, but may secondarily involve the
periosteum, cortex or medullary canal. To be qualified as extraskeletal osteosarcoma, the
tumor must (1) arise in the soft tissue and not be attached to bone or periosteum, (2) have a
uniform sarcomatous pattern (to exclude the possibility of mixed malignant mesenchymal
tumor), and (3) produce osteoid and/or cartilage matrix. 4,6
Plain radiographs, CT and MRI usually reveal a large deep-seated soft tissue mass
with variable mineralization. On radiograph, extraskeletal osteosarcoma often appears as soft
tissue opacity with variable amount of mineralization. Calcification or osteoid matrix
formation is present in approximately 50% of primary lesion. On CT, the tumor separate from
adjacent ossous structures and appears to have pseudocapsule. Matrix mineralization is best
appreaciated on CT rather than radiograph or MRI. On MRI, the tumor is usually a relatively
well circumscribed heterogenous mass, which isointense to skeletal muscle on T1 weighted
sequences and isointense to mildly hyperintense relative to skeletal muscle on T2 weightted
sequences. The presence of hemorrhage is not rare and may be represented by hyperintense
foci on T1-T2 weighted sequences, consistent with methmoglobin, or hypointense foci on T2
weighted sequence, consistent with hemosiderrin deposition. 7
Extraskeletal osteosarcomas range in size from 1-50 cm (mean 8-10 cm) and are
circumscribed, tan-white, haemorrhagic and focally necrotic gritty masses. All of the major
subtypes of osteosarcoma that arise in bone may be seen in EO. The most common is the
osteoblastic variant, followed by the fibroblastic, chondroid, telangiectatic, small cell, and
well differentiated types. The tumour cells are spindle or polyhedral cells that are
cytologically atypical, are mitotically active and frequently demonstrate atypical mitotic
figures. The bone is usually most prominent in the centre of the tumour with the more
densely cellular areas located in the periphery a pattern that is the reverse of myositis
ossificans. Telangiectatic EOs contain numerous large blood filled spaces lined by malignant
cells. Sheets of small round cells that mimic Ewing sarcoma or lymphoma are typical of the
small cell variant. The extremely rare well differentiated subtype contains abundant bone
deposited in well formed trabeculae, surrounded by a minimally atypical spindle cell
component similar to parosteal osteosarcoma. 7
Extraskeletal osteosarcoma, similar to its bone counterpart, was charactheristic by
fully malignant, anaplastic spindle cell proliferation, with the presence of osteoid matrix or
immature bone formed by neoplastic cell. Malignant condroid areas also observed in
association with osteoid or bone component. Occasionally, extraskeletal osteosarcoma has
been mistaken for myositis ossificans. Extraskeletal osteosarcoma can be difficult to
distinguish from MFH, Fibrosarcoma and malignant schwanoma. The pathologic diagnosis
is confirmed by the presence of neoplastic osteoid, with or without cartilage matrix, produced
by the malignant mesenchymal cells, identical morphologically to primary osteogenic
sarcoma of the bone. 2,5,6
Recommended treatment has primarily been surgical. The surgical treatment reported
in the literature has involved intralesional excision, marginal excision, wide excision, radical
excision as an initial operation with or without adjuvant radiation depending on the overall of
the lesion. Radical resections are effective for local control and have the best change of cure
the lungs are the most common site for metastasis (80% of cases) and resection of metastasis
can occasionally achieve a cure. However, chemotherapy and radiotherapy may be useful in
an aggressive multimodality approach to this tumor. Adjuvant radiation and chemotherapy
are considered for high risk lesion (high grade, large) and for incomplete resections. Adjuvant
radiation therapy decreases local recurrences in soft tissue sarcomas, however, most studies
regarding radiation and soft tissue sarcomas do not include cases of extraskeletal
osteosarcoma, if specified at all. 1,5,6
Extraskeletal osteosarcoma has a very poor prognosis and approximately 75% of
patients die of disease within 5 years of diagnosis. More than half of the patient have multiple
recurrences and metastasis. Most local recurrences and distant metastases occur within 3
years postoperatively. Lee and colleagues, found no association between size and
survivability. Therefore, a classification system that guides treatment on basis of prognostic
factors is as yet unefined. Nevertheless, as metastasis is the main factor in survival rate, early
diagnosis is imperative. 4,5,6
CONCLUSION
Extraskeletal osteosarcoma is a rare neoplasm that accounts for 1-2% of all soft tissue
sarcomas and approximately 2- 4% of all osteosarcomas. Classification system that guides
treatment on basis of prognostic factors is as yet undefined. Nevertheless, as metastasis is the
main factor in survival rate, early diagnosis is imperative
Refferences
1. Lisa E. Choi, MD et al. Analysis of Outcomes in Extraskeletal Osteosarcoma: A Review of
Fifty-three Cases. Memorial Sloam-Kettering Cancer Center, New York, NY. Journal Bone
Joint Surgery. 2014; 96: e2 (1-8)
2. Martin D. McCarter et al. Extraskeletal Osteosarcoma: Analysis of Outcome Of Rare
Neoplasm. Memorial Sloam-Kettering Cancer Center, New York, NY. Sarcoma.2000. 4,
119-123
3. Fouzia Lateef et al. Extraskeletal Osteosarcoma. Departement of Hystophatology. Dr.
Ziauddin Hospital, Karachi. Journal of the Collage of Physician and Surgeon Pakistan. 2011.
Vol. 21 (7): 429-430
4. Christhoper D.M. Fletcher et al. Pathology and Genetics of Tumours of Soft Tissue and
Bone. WHO. IARCPress. Lyon. 2002
5. Brian E. Welczak et al. Rare Extraskeletal Osteosarcoma in the Anterolateral Right Leg of
a 37-Year-Old Man. Department Orthopaedic Surgery, Mount Clemens Regional Medical
Centre, Michigan. Am J Orthop. 2009; 38(5): E93-E97
6. Joy S.Y.Lee, M.D et al. A Review of 40 Patients With Extraskeletal Osteosarcoma.
Division Anathomic Pathology and the Department of Orthopaedic, Mayo Clinic and Mayo
Foundation, Rochester, Minesota. 1995
7. Grainne Mc Auley et al. Extraskeletal Osteosarcoma: Spectrum of Imaging Findings.
Department of Radiology, Dana Ferber Cancer Institute, Havard Medical School, 450
Broklyn Ave, Boston. MA. AJR 2012; 198:W31-W37