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Bone-forming Tumors
Dr Ghulam Mustafa
Bone-forming Tumors A. BENIGN • 1. Osteoma • 2. Osteoid osteoma • 3. Osteoblastoma • 4. Ossifying fibroma
B. MALIGNANT • 1. Osteogenic sarcoma
OSTEOMA
Benign tumor of membranous bone (hamartoma) Age: adult life Associated with: Gardner syndrome (multiple osteomas + colonic polyposis) Location: inner / outer table of calvarium (usually from external table), paranasal sinuses (frontal / ethmoid sinuses), mandible, nasal bones Well-circumscribed round extremely dense structure less lesion usually <2 cm in size
Osteoma, frontal sinus. Red arrows point to round density in the right frontal sinus with the characteristic appearance of an osteoma.
very large frontal osteoma (located between and above the orbits
Axial image with arrows pointing to large left frontal sinus osteoma extending intracranially and obstructing the contralateral right frontal sinus
(FS).
Coronal image with arrows pointing to the large frontal sinus osteoma extending intracranially and into the frontal recess. Note the inferior
displacement of the left globe.
OSTEOID OSTEOMA
• Benign skeletal neoplasm composed of osteoid+ woven bone
• less than 1.5 cm in diameter per definition • Incidence: 12% of benign skeletal neoplasms Etiology: Inflammatory responseAge: 10-20 years (51%); 2nd+ 3rd decade (73%); 5-25 years (90%); range of 19 months-56 years; uncommon <5 and >40 years of age; M-:-F = 2-:-1; uncommon in Blacks
OSTEOID OSTEOMA • Tender to touch + pressure • Local pain (95-98%), weeks to years in duration, worse at night, decreased by activity • Salicylates give relief in 20-30 minutes in 75-90% • Prostaglandin E2 elevated 100-1000 x normal within nidus (probable cause of pain and vasodilatation)
OSTEOID OSTEOMA • Location: (a) Meta / diaphysis of long bones (73% ): upper end of femur (43%), hands (8%), feet (4%); frequent in proximal tibia +femoral neck, fibula, humerus; no bone exempt (b) spine (10-14%): predominantly in posterior elements (50% in pedicle+ lamina+ spinous process; 20% in articular process) of lumbar (59%), cervical (27% ), thoracic (12%), sacral (2%) segments • painful scoliosis, focal / radicular pain • gait disturbance, muscle atrophy (c) skull, rib, ischium, mandible, patella
OSTEOID OSTEOMA • Round / oval radiolucent nidus (75%) of <1.5 cm in size • Variable surrounding sclerosis ± central calcification • Painful scoliosis concave toward lesion / kyphoscoliosis / hyperlordosis / torticollis with spinal location (due to spasm) • May show extensive synovitis + effusion +premature loss
of cartilage with intraarticular site (lymphofollicular synovitis) • Osteoarthritis (50%) with intraarticular site 1.5-22 years
after onset of symptomatology • Regional osteoporosis (probably due to disuse) • Radiographically difficult areas: vertebral column, femoral neck, small bones of hand + feet
• Subperiosteal osteoid osteoma of the tibial diaphysis in an 18-year-old man. Oblique radiograph shows a radiolucent nidus (arrow) amid an area of fusiform cortical thickening
• Osteoid osteoma of the posterior arc of the rib in a 25-year-old man. (a)Anteroposterior radiograph shows a teardrop-shaped nidus (arrow) with central mineralization. Mild reactive sclerosis and cortical expansion of the host bone also are seen in the surrounding bone.
• Intraarticular osteoid osteoma of the femoral condyle in a 29-year-old man. (a) Lateral radiograph of the knee shows a densely mineralized nidus (arrow) at the lateral femoral condyle.
• Intraarticular osteoid osteoma of the humerus in a 13-year-old boy.Anteroposterior radiograph shows periarticular osteopenia and extensive periosteal reaction (arrows) in the distal humerus and a round calcified nidus (arrowhead) in the olecranon fossa.
OSTEOID OSTEOMA
NUCLEAR SCAN: Intensely increased radiotracer uptake (increased blood flow + new-bone formation) double density sign= small area of focal activity (nidus) superimposed on larger area of increased tracer uptake CT (for detection+ precise localization of nidus): small well-defined round / oval nidus surrounded by variable amount of sclerosis • nidus enhances on dynamic scan • nidus with variable amount of mineralization (50%): • punctate / amorphous / ringlike / dense
OSTEOID OSTEOMA
MR (diminished conspicuity of lesion compared with CT): • nidus isointense to muscle on TlWI • signal intensity increases to between that of muscle + fat • remains low on T2WI • peri nidal inflammation of bone marrow (63%) • peri nidal soft-tissue inflammation I edema (47%) • synovitis +joint effusion with intraarticular site Angiography: • highly vascularized nidus with intense circumscribed
blush appearing in early arterial phase+ persisting late into venous phase
• Subperiosteal osteoid osteoma of the tibial diaphysis in an 18-year-old man.
• Axial unenhanced CT image shows a low-attenuation nidus (arrow), without mineralization, surrounded by reactive bone formation (white arrowheads). The attenuation of the reactive bone is slightly lower than that of the native cortex (black arrowheads). The nidus is classified as subperiosteal because it is adjacent to the outer margin of the native cortex.
• Osteoid osteoma of the lumbar spine in a 22-year-old man. (a) Anteroposterior radiograph shows mild scoliosis and an enlarged left L3 pedicle with sclerotic change (arrow). The curvature of the scoliosis is leftward, with the lesion located within the concavity.
• Intraarticular osteoid osteoma of the femoral condyle in a 29-year-old man. Axial T2-weighted MR image shows the low-signal-intensity nidus with central calcification (arrow) and a high-signal-intensity, unmineralized periphery (arrowheads).
• Osteoid osteoma of the posterior arc of the rib in a 25-year-old man. Axial unenhanced CT image shows the calcified nidus (arrow) in the anterior cortex of the rib, with mild reactive sclerosis (arrowheads) surrounding the nidus.
• Sagittal gadolinium-enhanced T1-weighted fat-suppressed MR image shows hypertrophic synovitis in the elbow joint and the enhancing nidus (arrowhead) in the olecranon fossa. Extensive bone marrow edema (*) and periosteal reaction (arrows) are seen in the distal humeral metaphysis.
• Osteoid osteoma of the sacrum in a 16-year-old boy. Sagittal reformatted CT image shows a calcified nidus (arrow) protruding into the central canal, with reactive sclerosis (*) around the nidus.
OSTEOID OSTEOMA Prognosis: no growth progression, infrequent regressionRx:(1) complete surgical excision of nidus (reactive bone regresses subsequently) (2) percutaneous CT-guided removal (3) percutaneous ablation with radio-frequency electrode / laser / alcohol
OSTEOID OSTEOMA
DDx: (1) Cortical osteoid osteoma: Brodie abscess, sclerosing osteomyelitis, syphilis, bone island, stress fracture,osteosarcoma, Ewing sarcoma, osteoblastic metastasis, lymphoma, subperiosteal aneurysmal bone cyst, osteoblastoma (progressive growth) (2) Intraarticular osteoid osteoma: inflammatory / septic / tuberculous / rheumatoid arthritis, nonspecific synovitis / Legg-Calve-Perthes disease
Cortical Osteoid Osteoma (most common)
Nidus within cortex
Solid / laminated periosteal reaction
Fusiform sclerotic cortical thickening in shaft of long bone
Radiolucent area within center of osteosclerosis
Cancellous Osteoid Osteoma (intermediate frequency)
intramedullary / Intraarticular lesion difficult to identify with delay in diagnosis of 4 months-5 years
Site: Juxta / intraarticular at femoral neck, vertebral posterior elements, small bones of hands + feet
little osteosclerosis / sclerotic cortex distant to nidus
(functional difference of intraarticular periosteum) joint space widened (effusion, synovitis)
Subperiosteal Osteoid Osteoma (rare)
round soft-tissue mass adjacent to bone
Site: juxta / intraarticular at medial aspect of femoral
neck, hands, feet (neck of talus)
juxtacortical mass excavating the cortex (bony pressure atrophy) with almost no reactive sclerosis
Scintigraphic Findings
Radionuclide skeletal scintigraphy characteristically reveals intense activity at the site of the nidus and relatively decreased activity in the surrounding reactive zone, a pattern referred to as the double-density sign.
Scintigraphy may be useful for lesion localization, particularly in cases with normal or nearly normal radiographic findings.
• Double-density sign produced by radionuclide uptake in osteoid osteoma. Anterior planar view of the knees obtained with technetium medronate scintigraphy in a 20-year-old woman demonstrates intense activity in the nidus of a lesion in the intercondylar region of the distal left femur (arrow) with surrounding mild activity. This combination of findings, known as the double-density sign, is pathognomonic of osteoid osteoma.
OSTEOBLASTOMA Rrare benign tumor with unlimited growth potential +capability of malignant transformation
Incidence: <1% of all primary bone tumors; 3% of all benign bone tumors
Age: mean age of 16-19 years; 6-30 years (90%); 2nd decade (55%); 3rd decade (20%); M7F = 271
• Path: lesion > 1.5 cm; smaller lesions are classified as osteoid osteoma
OSTEOBLASTOMA
• asymptomatic in <2% • dull localized pain of insidious onset (84% ), worse at night in 7-13% • response to salicylates in 7% • localized swelling, tenderness, decreased range of motion (29%) • painful scoliosis in 50% (with spinal / rib location) secondary to muscle spasm, may be convex toward side of tumor • paresthesias, mild muscle weakness, paraparesis, paraplegia (due to cord compression) • occasional systemic toxicity (high WBC, fever)
OSTEOBLASTOMA
Location: (rarely multifocal)
(a) spine (33-37%): 62-94% in posterior elements, secondary extension into vertebral body (28-42%); cervical spine (31% ), thoracic spine (34% ), lumbar spine (31%), sacrum (3%) (b) long bones (26-32%): femur (50%), tibia (19%), humerus (19%), radius (8%), fibula (4%); unusual in neck of femur (c) small bones of hand+ feet (15-26%): dorsal talus neck (62%), calcaneus (4%), scaphoid (8%), metacarpals (8%), metatarsals (8%) (d) calvarium+ mandible(= cementoblastoma)
OSTEOBLASTOMA
CT: • multifocal matrix mineralization, sclerosis • expansile bone remodeling, thin osseous shell NUCLEAR SCAN: • intense focal accumulation of bone agent (100%) Angio: • tumor blush in capillary phase (50%) MR: • low to intermediate signal intensity on TlWI • mixed intermediate to high intensity on T2WI • surrounding edema
OSTEOBLASTOMA Prognosis: 10% recurrence after excision; incomplete curettage can effect cure due to cartilage production + trapping of host lamellar boneDDx: (1) Osteo / chondrosarcoma (periosteal new bone) (2) Osteoid osteoma (dense calcification+ halo of bone sclerosis, stable lesion size <2 cm due to limited growth potential) (3) Cartilaginous tumors (lumpy matrix calcification (4) Giant cell tumor (no calcification, epiphyseal involvement) (5) Aneurysmal bone cyst (6) Osteomyelitis (7) Hemangioma (8) Lipoma (9) Epidermoid (10) Fibrous dysplasia (11) Metastasis (12) Ewing sarcoma
Osteoblastoma of Proximal humerus
An 18-year-old male presented with pain in his neck. This lateral radiograph of the cervical spine shows a 2 cm lytic lesion
arising from the pedicle of C7 with osteoblastic changes seen at the
periphery of the lesion and inflammatory softening and slight collapse of the
intervertebral disk space between C6 and C7.
AP radiograph of the lumbar spine shows a dense
osteoblastic lesion arising from the pedicle and
transverse process of the L4 vertebra on one side only. It
represents a burnout osteoblastoma which is
totally asymptomatic and was picked up as an
incidental finding. There is no need for treatment of this
lesion which is totally inactive.
Lateral radiograph of the elbow of 53 old patient. There is an osteoid-forming lesion measuring 3 cm in diameter in the same location where he had his osteoid osteoma removed. This was biopsied and proved to be an
osteoblastoma because the nidus was larger than 1.5 cm.
Osteoblastoma of Distal Femur
Osteoblastoma of distal femurIntermediate signal on T1WI
high signal intensity on T2WI with punctate low signal areas consistent
with mineralization, Extensive edema around the lesion(high signal in
medullary canal)
T1WI
T2WI
T2WI Coronal
Osteoblastoma of distal radiusGeographic Lesion
Well circumscribed
This AP radiograph of the pelvis of a 19-year-old boy shows osteoblastic changes occurring in the medial acetabulum extending
up into the supra-acetabular area. There is reactive new bone formation on the inner aspect of the pelvis extending out into the superior pubic ramus and bulging into the retroperitoneal space a
distance of approximately 3 cm.
Postoperative AP radiograph after aggressive resection of the periacetabular tumor and reconstruction with a cemented total hip replacement with an
all-poly cup.
OSSIFYING FIBROMA• Closely related to fibrous dysplasia+
adamantinoma
• Age: 2nd-4th decade; M < F
• Histo: maturing cellular fibrous spindle cells with osteoblastic activity producing many calcific cartilaginous + bone densities
OSSIFYING FIBROMALocation: frequently in face Mandible, maxilla • painless expansion of tooth-bearing portion of jaw 1-5 cm well-circumscribed round / oval tumor moderate expansion of intact cortex homogeneous tumor matrix dislodgment of teeth Tibia eccentric ground-glass lesion (resembling fibrous dysplasia)
OSSIFYING FIBROMA
Ossifying fibroma in the left mandible with divergence of teeth and erosion of the inferior cortex (arrows).
Ossifying fibroma in a 33-year-old woman. CT scan reveals a circular, partially calcified lesion (arrow) within the mandible. Note the internal ground-glass
calcifications.
OSTEOSARCOMA• Most common malignant primary bone tumor in
young adults + children; 2nd most common primary malignant bone tumor after multiple myeloma
• Prevalence: 4-571,000,000; 15% of all primary bone tumors confirmed at biopsy
• Types & Frequency: • A. Conventional osteosarcoma: high-grade intramedullary ..... . 75% telangiectatic ........... ... 4.5-11% low-grade intraosseous ... . .... 4-5%
OSTEOSARCOMA small cell . ... ... . ... ..... .. . 1-4% osteosarcomatosis . . ..... ..... 3-4% gnathic . ....... ... ....... . . . 6-9% B. Surface / juxtacortical osteosarcoma:.... 4-10% intracortical. . ... . ... .... .. . . .. rare parosteal . . ....... ......... .. 65% periosteal. ............. ...... 25% high-grade surface . . . . . . . . . . . . 10% C. Extraskeletal ..................................................... 4% D. Secondary osteosarcoma .............................. 5-7%
OSTEOSARCOMAWork-up:
local staging by MR before biopsy
distant staging with bone scan + chest CT
Extraskeletal Osteosarcoma
located within soft tissue without attachment to bone / periosteum Incidence: 1.2% of soft-tissue sarcomas Histo: variable amounts of neoplastic osteoid+ bone +cartilage; frequently associated with fibrosarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumor Mean age: 50 years; 94% >30 years of age; M > F Location: lower extremity (thigh in 42-47%), upper extremity (12-23%), retroperitoneum (8-17%), buttock, back, orbit, submental, axilla, abdomen, neck, kidney, breast
Extraskeletal Osteosarcoma • slowly growing firm soft-tissue mass • painful+ tender (25-50%) • history of trauma (12-31%): in preexisting myositis • elevated levels of alkaline phosphatase (prognostic) • often deep-seated+ fixed soft-tissue tumor
(average diameter of 9 cm) • focal / massive area of mineralization (>50%) • faint moderate inhomogeneous enhancement • increased radionuclide uptake on bone scan
Extraskeletal Osteosarcoma
Prognosis: (1) multiple local recurrences (in 80-90%) after interval of 2 months to 10 years (2) metastases after interval of I month to 4 years: lungs (81-100%), lymph nodes (25%), bone, subcutis, liver (3) death within 2-3 years (>50%) with tumor size as major predictor
High-grade Intramedullary Osteosarcoma
= CENTRAL OSTEOSARCOMA= CONVENTIONAL OSTEOSARCOMA Histo: arising from undifferentiated mesenchymal tissue; forming fibrous I cartilaginous I osseous matrix (mostly mixed) that produces osteoid I immature bone (a) osteoblastic (50-80%) (b) chondroblastic (5-25%) (c) fibroblastic-fibrohistiocytic (7-25%) Age: bimodal distribution 10-25 years and >60 years; 21% <10 years; 68% <15 years; 70% between 10 and 30 years• painful swelling (1-2 months' duration) • fever (frequent) • slight elevation of alkaline phosphatase Openmirrors.com
High-grade Intramedullary Osteosarcoma
• diabetes mellitus (paraneoplastic syndrome) in 25%
• Location: long bones (70-80%), femur (40-45%), tibia (16-20%); 50-55% about knee; proximal humerus
• (10-15%); facial bones (8%); cylindrical bone • <30 years; fiat bone (ilium) >50 years • Site: origin in metaphysis (90-95%) / diaphysis (2-
11 %) / epiphysis ( <1% ); growth through open physis with extension into epiphysis (75-88%)
High-grade Intramedullary OsteosarcomaDoubling time: 20-30 day usually large bone lesion of >5-6 cm when first detected cloudlike density (90%) I almost normal density / osteolytic (fibroblastic type) aggressive periosteal reaction: sunburst / hair-on-end / onion-peel = laminated / Codman triangle moth-eaten bone destruction + cortical disruption soft-tissue mass with tumor new bone (osseous /cartilaginous type) transphyseal spread before plate closure (75-88%); physis does NOT act as a barrier to tumor spread spontaneous pneumothorax (due to subpleural metastases)
High-grade Intramedullary Osteosarcoma
NUC (bone scintigraphy): intensely increased activity on blood flow, blood pool, delayed images (hypervascularity, new-bone formation) soft-tissue extension demonstrated, especially with SPECT .Y bone scan establishes local extent (extent of involvement easily overestimated due to intensity of uptake), skip lesions, metastases to bone + soft tissues
High-grade Intramedullary Osteosarcoma
CT: Soft-tissue attenuation (non mineralized portion) replacing fatty bone marrow low attenuation (higher water content of
chondroblastic component / hemorrhage / necrosis)
very high attenuation (mineralized matrix)
High-grade Intramedullary Osteosarcoma
MR (preferred modality): tumor of intermediate signal intensity on TlWI +high signal intensity on T2WI clearly defines marrow extent (best on TlWI), vascular involvement, soft-tissue component (best on T2WI) Evaluate for: (I) extent of marrow+ soft-tissue involvement (2) invasion of epiphysis (3) joint (19-24%) +neurovascular involvement (4) viable tumor+ mineralized matrix for biopsy
High-grade Intramedullary Osteosarcoma
Metastases (in 2% at presentation): (a) hematogenous lung metastases (15%):
calcifying; spontaneous pneumothorax secondary to subpleural cavitating nodules rupturing into pleural space (b) lymph nodes, liver, brain (may be calcified) (c) skeletal metastases uncommon (unlike Ewing sarcoma); skip lesions= discontinuous tumor foci in marrow cavity in 1-25%
High-grade Intramedullary Osteosarcoma
Cx: (1) pathologic fracture (15-20%) (2) radiation-induced osteosarcoma (30 years delay) Rx: chemotherapy followed by wide surgical resection Prognosis: 60-80% 5-year survival (1) Amputation: 20% 5-year survival; 15% develop skeletal metastases; 75% dead within <2 years (2) Multidrug chemotherapy: 55% 4-year survival more proximal lesions carry higher mortality (0% 2-year survival for axial primary) Predictors of poor outcome: metastasis at presentation, soft-tissue mass >20 cm, pathologic fracture, skip lesions in marrow
High-grade Intramedullary Osteosarcoma
Predictors of poor response to chemotherapy: no change / increase in size of soft-tissue mass, increase in bone destruction DDx: 1. Osteoid osteoma2. sclerosing osteomyelitis3. Charcot joint
High-grade Surface Osteosarcoma
Location: femur, humerus, fibula Site: • diaphysis • similar to periosteal osteosarcoma often
involves entire circumference of bone • frequent invasion of medullary canal Prognosis: identical to conventional Intramedullary osteosarcoma
lntracortical Osteosarcoma Rarest form of osteosarcoma Histo: sclerosing variant of osteosarcoma which may contain small foci of chondro-or fibrosarcoma Location: femur, tibia tumor <4 em in diameter intracortical geographic bone lysis tumor margin may be well defined with thickening of surrounding cortex metastases in 29%
Low-grade Intraosseous Osteosarcoma
WELL-DIFFERENTIATED / SCLEROSING OSTEOSARCOMA Path: penetration among bony trabeculae; fibrous stroma sometimes lacking nuclear atypia + pleomorphism; highly variable amount of tumor osteoid production; may be misinterpreted as fibrous dysplasia Age: most frequently 3rd decade; M:F = 1:1 • protracted clinical course with nonspecific symptoms
Low-grade Intraosseous Osteosarcoma
Location: about the knee; femur involved in 50% Site: • metaphysis; often with extension into epiphysis • may have well-defined margins+ sclerotic rim • diffuse sclerosis • expansile remodeling of bone • esubtle signs of aggressiveness: bone lysis, focally
indistinct margin, cortical destruction, soft-tissue mass,
• periosteal reaction
Low-grade Intraosseous Osteosarcoma• The relatively benign appearance has resulted
in misdiagnosis as a benign entity! • Cx: transformation into high-grade
osteosarcoma • Prognosis: similar to parosteal osteosarcoma;
80-90% • 5-year survival rate; local recurrence in 10%
(due to inadequate resection) • DDx: fibrous dysplasia, nonossifying fibroma, • chondrosarcoma, chondromyxoid fibroma
Osteosarcoma of Jaw = GNATHIC OSTEOSARCOMA Average age: 34 years (10-15 years older than in conventional osteosarcoma) Histo: chondroblastic predominance (-50%), osteoblastic predominance (-25%); better differentiated (grade 2 or 3) than conventional osteosarcoma (grade 3 or 4) • simulating periodontal disease: rapidly enlarging mass, lump, swelling • paresthesia (if inferior alveolar nerve involved) • painful I loose teeth, bleeding gum
Osteosarcoma of Jaw
Location: body of mandible (lytic)alveolar ridge of maxilla (scleroticmaxillary antrum osteolytic / osteoblastic / mixed pattern• osteoid matrix (60-80%) • aggressive periosteal reaction for mandibular lesion • soft-tissue mass (100%) opacification of maxillary
sinus (frequent in maxillary lesions) Prognosis: 40% 5-year survival rate (lower probability of metastases, lower grade)
Osteosarcoma of Jaw
• DDx: metastatic disease (lung, breast, kidney), multiple
• myeloma, direct invasion by contiguous tumor from • oral cavity, Ewing sarcoma, primary lymphoma • of bone, chondrosarcoma, fibrosarcoma, acute • osteomyelitis, ameloblastoma, Langerhans cell • histiocytosis, giant cell reparative granuloma,
"brown • tumor" of HPT
Osteogenic sarcoma
AP radiograph of the proximal humerus in a 12-year-old girl shows a destructive, permeative lytic lesion of the upper 7 inches of the humerus with extensive cortical invasion medially. The lesion was biopsied and proven to be an osteogenic sarcoma. Other considerations in the differential diagnosis would include Ewing's sarcoma.
AP and lateral radiographic views of the proximal tibia show an aggressive osteosarcoma arising from the original non-ossifying fibroma, a very rare
and unusual secondary event for the non-ossifying fibroma. On biopsy, the lesion proved to be a malignant osteosarcoma and the patient was started
on adjuvant chemotherapy.
bone scan that shows increased activity in the upper half of the tibia with no other skeletal sites involved.
Sagittal T2-weighted MRI shows the very bright signal abnormality filling the entire upper half of the tibial area with circumferential
subperiosteal involvement as well, signifying an aggressive pattern.
Sagittal gadolinium contrast MRI showing extensive pickup of the gadolinium in the high signal tumor, both within the medullary canal and
breaking out anteriorly under the periosteum.
Osteogenic sarcoma, parosteal - Proximal humerus - X-ray- A 41-year-old female presented with a surface-type, ossifying lesion of the upper humeral diaphysis that had been growing for six months. This AP radiograph of the humerus shows fairly mature neoplastic bone arising circumferentially around the upper diaphysis of the humerus with a small area of lysis in the center of the tumor suggesting a more aggressive pattern to the disease. A biopsy of this area revealed a high-grade but surface type osteogenic sarcoma, necessitating the use of adjuvant chemotherapy along with surgical resection.
Periosteal osteogenic sarcoma in a 28-year-old woman with lower calf
pain. Radiograph shows cortical destruction (arrows) in the posterior
cortex of the tibial diaphysis with surrounding new bone formation.
The appearance is typical of a periosteal osteogenic sarcoma.