3 Introduction Forms 0.2% of human tumor burden Primary malig bone tumors make 1% of all malignant tumorsCarcinoma commonly metastasize to LN except BCCSarcomas commonly metastasize hematogenouslyMost have male predominance excep GCT, ABC
4 Classification Based on tissue of origin Bone Cartilage Fibrous tissue Bone marrowBlood vesselsMixedUncertain origin
12 Radiography Information yielded by radiography includes : Site of the LesionBorders of the lesion/zone of transitionType of bone destructionPeriosteal reactionMatrix of the lesionNature and extent of soft tissue involvement
14 Site of the LesionDetermined by the laws of field behavior and developmental anatomy of the affected bone, a concept first popularized by Johnson.Parosteal osteosarcoma -posterior aspect of the distal femurChondroblastoma -epiphysis of long bones before skeletal maturityAdamantinoma and osteofibrous dysplasia have a specific predilection for the tibiaA lesion's location can also exclude certain entities from the differential diagnosis.E.g Giant cell tumor -articular end of bone.Location in relation to the central axis of the bone esp in long tubular bone, such as humerus, radius, femur, or tibia.For example, simple bone cyst, enchondroma, or a focus of fibrous dysplasia -always centrally locatedEccentric location is Xteristically observed in aneurysmal bone cyst, chondromyxoid fibroma, and nonossifying fibroma
15 Predilection of Tumors for Specific Sites in the Skeleton
16 Site of the lesion. Parosteal osteosarcoma Adamantinoma Chondroblastoma
17 Site of the lesion.Distribution of various lesions in a long tubular bone in a growing skeletonDistribution of various lesions in a long tubular bone after skeletal maturity
18 Site of the lesion.Location of epicenter of lesion usually determines site of its origin (medullary, cortical, periosteal, soft tissue, or in the joint)
19 Distribution of various lesions in a vertebra. Malignant lesions are seen predominantly in its anterior part (body)Benign lesions predominate in its posterior elements.
20 Borders/margins of the Lesion Margins determined by GRate hence benign or malignantThree types of lesion margins are encountered:Sharp demarcation by sclerosis (IA margin),sharp demarcation without sclerosis (IB margin)Ill-defined margin (IC margin)Slow-growing lesions -sharp sclerotic borders;usually indicates that a tumor is benignE.g nonossifying fibroma, simple bone cystIndistinct borders- typical of malignant or aggressive lesionsPost- Radio- or chemo of malignant bone tumorsCan exhibit sclerosis and a narrow zone of transitionThe borders/margins -crucial in determining the growth rate hence whether benign or malignantThree types of lesion margins are encountered:Sharp demarcation by sclerosis (IA margin),sharp demarcation without sclerosis around the periphery of the lesion (IB margin), andIll-defined margin region (entire circumference or a portion of it) -(IC margin)Slow-growing lesions are marked by sharply outlined, sclerotic borders;usually indicates that a tumor is benignE.g nonossifying fibroma, simple bone cyst, and chondromyxoid fibromaIndistinct borders (a wide zone of transition), are typical of malignant or aggressive lesionsPost- Radio- or chemo of malignant bone tumorsCan exhibit sclerosis and a narrow zone of transition
21 determine its growth rate. Borders of the lesiondetermine its growth rate.sharp scleroticsharp lyticill-defined.
22 Borders of the lesion. A: Sclerotic border typifies a benign lesion e.g nonossifying fibroma in the distal femur.B: A wide zone of transition typifies an aggressive or malignant lesion e.g plasmacytoma involving the pubic bone and supraacetabular portion of the right iliumA: Sclerotic border or narrow zone of transition from normal to abnormal bone typifies a benign lesion e.g nonossifying fibroma in the distal femur.B: A wide zone of transition typifies an aggressive or malignant lesion e.g plasmacytoma involving the pubic bone and supraacetabular portion of the right ilium
23 Type of Bone Destruction Mechanisms of bone destructionDirect effect of tumor cellsIncr osteoclastic activityCortical bone is destroyed less rapidly than trabecular bone.Loss of cortical bone appears earlier on radiographytrabecular bone must be destroyed (about 70% loss of mineral content) before the loss becomes radiographically evidentBone destruction can be described asgeographic (type I) - benign lesionsmoth-eaten (type II) andpermeative (type III) - rapidly growing infiltrating tumorsMechanisms of bone destructionDirect effect of tumor cellsComplex mechanism in which normal osteoclasts of the host bone respond to pressure generated by the enlarging mass and by active hyperemia associated with the tumorCortical bone is destroyed less rapidly than trabecular bone.However, loss of cortical bone appears earlier on radiography because its density is highly homogeneous compared with that of trabecular bone. In the latter, greater amounts of bone must be destroyed (about 70% loss of mineral content) before the loss becomes radiographically evident (134). Like the borders of a lesion, the type of bone destruction caused by a tumor indicates its growth rate.Bone destruction can be described asgeographic (type I),moth-eaten (type II), andpermeative (type III) (105,107) (Fig. 1-12).Although none of these features are pathognomonic for any specific neoplasm, the type of destruction may suggest a benign or a malignant process.Geographic bone destruction is characterized by a uniformly destroyed area usually within sharply defined borders. It typifies slow-growing, benign lesions, such as simple bone cyst, enchondroma, chondromyxoid fibroma, or giant cell tumor.On the other hand, moth-eaten (i.e., characterized by multiple, small often clustered lytic areas) and permeative (i.e., characterized by ill-defined, very small oval radiolucencies or lucent streaks) types of bone destruction mark rapidly growing, infiltrating tumors, such as myeloma, lymphoma, fibrosarcoma, or Ewing sarcoma. However, some nonneoplastic lesions may demonstrate this aggressive pattern. For example, osteomyelitis can exhibit both type II (moth-eaten) and type III (permeative) patterns of destruction (133). Similarly, hyperparathyroidism can cause a permeative pattern (113). The distinction between a moth-eaten and a permeative pattern of destruction may be subtle; often the two patterns coexist in the same lesion
24 Patterns of bone destruction. permeative type characteristic of round cell tumorsgeographica uniformly affected area within sharplydefined bordersmoth-eatenrapidly growing infiltrating lesionsgiant cell tumor.myelomaEwing sarcoma
25 Periosteal Responsethe pattern of periosteal reaction is an indicator of the biologic activity of a lesion .periosteal reactionsthat can be categorized as;uninterrupted (continuous) or Interrupted (discontinuous).Any widening and irregularity of bone contour may represent periosteal activity.An uninterrupted periosteal reaction indicates a long-standing (slow- growing), usually indolent, benign process.There are several types of solid periosteal reaction:a solid buttress e.g aneurysmal bone cyst and chondromyxoid fibroma;a solid smooth or elliptical layer e.gosteoid osteoma and osteoblastoma;a single lamellar reaction, such as accompanies Langerhans cell histiocytosisSunburst (“hair-on-end”) or onion-skin (lamellated) pattern .Codman trianglethe pattern of periosteal reaction is an indicator of the biologic activity of a lesion . Bone neoplasms elicit periosteal reactions that can be categorized as uninterrupted (continuous) or interrupted (discontinuous). Any widening and irregularity of bone contour may represent periosteal activity. The solid periosteal reaction represents a single solid layer or multiple closely apposed and fused layers of new bone attached to the outer surface of the cortex. The resulting pattern is often referred to as cortical thickening. Although no single periosteal response is unique for a given lesion, an uninterrupted periosteal reaction indicates a long-standing (slow-growing), usually indolent, benign process. There are several types of solid periosteal reaction: a solid buttress, such as is frequently seen accompanying aneurysmal bone cyst and chondromyxoid fibroma; a solid smooth or elliptical layer, such as is seen in osteoid osteoma and osteoblastoma; an undulating type, most frequently seen in long-standing varicosities, pulmonary osteoarthropathy, chronic lymphedema, periostitis, and, rarely, with neoplasms; and a single lamellar reaction, such as accompanies osteomyelitis,Langerhans cell histiocytosis, and stress fracture. An interrupted periosteal response, on the other hand, is commonly seen in malignant primary tumors and less commonly in some metastatic lesions and highly aggressive nonmalignant processes. In these tumors, the periosteal reaction may appear in a sunburst (“hair-on-end”) or onion-skin (lamellated) pattern . When the tumor breaks through the cortex and destroys the newly formed lamellated bone, the remnants of the latter on both ends of the break-through area may remain as a triangular structure known as a Codman triangle
26 Types of periosteal reaction. An uninterrupted periosteal reaction usually indicates a benign process, whereas an interrupted reaction indicates a malignant or aggressive nonmalignant process
27 Examples of Nonneoplastic and Neoplastic Processes Categorized by Type of Periosteal Reaction
28 Interrupted type of periosteal reaction Ewing sarcoma -lamellated typelamellated or onion-skin type in ewing sarcomasunburst pattern -osteosarcomaCodman triangle (arrow)
29 Type of MatrixThe matrix represents the intercellular material produced by mesenchymal cellsE.g osteoid, bone, chondroid, myxoid, and collagen material .Type of matrix allows differentiation of some similar-appearingE.g differentiating osteoblastic from chondroblastic processes.Calcifications in the tumor matrix, point to a chondroblastic process.Calcifications typically appear as punctate (stippled), irregularly shaped (flocculent), or curvilinear (annular or comma-shaped, rings and arcs).Differential diagnosis of stippled, flocculent, or ring-and-arc calcifications includes enchondroma, chondroblastoma, and chondrosarcoma.A completely radiolucent lesion may be eitherfibrous or cartilaginous in origintumor-like lesions, such as simple bone cysts or intraosseous ganglion
30 Types of matrix: osteoblastic The matrix of a typical osteoblastic lesion is characterized by the presence of the following featuresA. fluffy, cotton-like densities within the medullary cavity, e.g in this case of osteosarcoma of the distal femurB. presence of the wisps of tumor-bone formation, like in this case of osteosarcoma of the sacrumC. by the presence of a solid sclerotic mass, such as in parosteal osteosarcoma
31 Types of matrix: chondroid matrix A: Schematic representation of variousappearances of chondroid matrix calcifications.B: Enchondroma displays a typical chondroid matrixC: Chondrosarcoma with characteristic chondroid matrix
32 Soft Tissue MassA bone lesion associated with a soft tissue mass should prompt the question of which came first.Is the soft tissue lesion an extension of a primary bone tumor, or is it a primary soft tissue tumor invading bone?
33 Radiographic features differentiating primary soft tissue tumor invading bone from primary bone tumor invading soft tissues.
34 Benign Versus Malignant Nature clusters of features that can be gathered from radiographs can help in favoring one designation over the other .Benign lesions usually havewell-defined sclerotic bordersexhibit a geographic type of bone destructionthe periosteal reaction is solid and uninterrupted, andthere is no soft tissue mass.Malignant tumors oftenexhibit poorly defined borders with a wide zone of transition;bone destruction appears in a moth-eaten or permeative pattern, andthe periosteum shows an interrupted, sunburst, or onion-skin reaction with an adjacent soft tissue mass.NB-benign lesions may also exhibit aggressive features
35 Radiographic features that may help differentiate benign from malignant lesions
36 Grading of bone sarcomas Criteria for gradingCellularityNuclear featuresMitotic figuresnecrosisCorrelates with prognosis in some tumorsE.g chondrosarcoma, malig vascular tumorsSome not amenable to histological grading e.g monomorphic tumorsEwing, MM, lymphomaSome always high gradeSometimes not useful in predicting prognosisAdamantinoma, chordoma
37 Staging of bone tumorsBenign tumors (Enneking staging of benign tumors)Stage 1 - latentStage 2 - activeStage 3 - aggressiveMalignant tumorsTNM stagingAJCC staging systemMusculoskeletal tumor society staging system(enneking)Surgical stagingNoteBenign tumors - classified using Arabic numerals(1,2,3)Malignant tumors - classified using roman numerals(I,II,III)
39 Enneking classification systems Enneking classification of benign tumorsLatent, active, aggressiveEnneking surgical staging of malignant tumorsEnneking classification of local proceduresIntracapsular, marginal, extended, radicalEnneking classification of amputations
43 Enneking staging of benign tumors Stage 1; LatentWell defined marginGrows slowly and then stopsHeals spontaneously eg osteoid osteomaNeglible recurrence after intracapsular resectionStage 2; ActiveProgressive growth limited by natural barriersWell defined margin but may expand thinning cortex e.g ABCNegligible recurrence after marginal excisionRx marginal resectionStage 3; aggressiveGrowth not limited by natural barriers e.g GCTMets present in 5% of these ptsHave high recurrence after intracapsular or marginal resectionExtended resection preferred
44 Enneking surgical Staging of malignant tumors Incorporatesdegree of differentiationLow grade(stage I) orHigh grade(stage II)Local extent of tumorIntracompartmental - AExtracompartmental - Bdistant spreadmetastasis
48 Bone biopsyOptionsNeedle biopsy90% accuracy at determining malignancyAccuracy at determining specific tumor much lowerAbsence of malignant cells less re-assuring than incisional biopsyCore biopsyProvides accurate diagnosis in 90% of casesincisional biopsyPrimary resection instead of biopsy can be done in;Small(<3cm) subc mass- marginally resected if likely malignantCharacteristic radiographic appearance of benign lesionPainful lesion in an expendable bone e.g prox fibula, distal ulna
49 Tumour Biopsy Principles 1 1.Biopsy done only after evaluation & imaging is complete.determine xteristics and local extent of the tumor and metsStaging helps determine the exact anatomic approach to tumorBiopsy superimposes radiologic changes at the biopsy site, and there4 can alter the interpretation of the imaging studies.2. Place small incisions whenever possible- skin & capsule3. The biopsy track be considered contaminated with tumor cells.Track excised en bloc with the tumor subsequently.4. The surgeon should be familiar with incisions for limb salvage surgery, and also with standard and nonstandard amputation flaps. 1.Biopsy should be done only after clinical, laboratory, and roentgenographic examinations are complete. This will help in planning the placement of the biopsy incision. It will also help to make an accurate diagnosis2. Place small incisions whenever possible, also use small capsular incisions over the tumour thus reducing bleeding3. The biopsy track should be considered contaminated with tumor cells. Placement of the biopsy incision therefore is important because the biopsy track should also be excised en bloc with the tumor subsequently.4. The surgeon should be familiar with incisions for limb salvage surgery, and also with standard and nonstandard amputation flaps. 5. If a tourniquet is used, the limb is elevated before inflation but should not be exsanguinated by compression because the latter may cause tumour spread.6. Care should be taken to contaminate as little tissue as possible. Transverse incisions should be avoided since they are extremely difficult or impossible to excise with the specimen. The deep incision should go through a single muscle compartment (muscle belly) rather than through an intermuscular plane. Major neurovascular structures should be avoided. Care should be taken not to contaminate flaps. Minimal retraction should be utilized to limit soft tissue contamination. .
50 Examples of poorly performed biopsies Needle biopsy track contaminated patellar tendonMultiple needle tracks contaminate quadriceps tendonNeedle track placed posteriorly, location that would be extremely difficult to resect en bloc with tumor if it had proved to be sarcoma.
51 Tumour Biopsy Principles 2 5. If a tourniquet is used;The limb is elevated before inflationAvoid exsanguination by compression.6. contaminate as little tissue as possible.Avoid transverse incisionsThe deep incision should go thru single muscle compartment (muscle belly) rather than through an intermuscular plane.Major neurovascular structures should be avoided.Care should be taken not to contaminate flaps.Minimal retraction should be utilized to limit soft tissue contamination.
52 Example of poorly performed biopsy Transverse incisions should not be used
54 Tumour Biopsy Principles 3 7. If possible soft tissue extension of a bone lesion should be sampled 8. If a hole must be made in the bone, it should be round or longitudinally oval to minimize stress concentration and prevent a subsequent fracture.A fracture may preclude a subsequent limb salvage surgery.PMMA is plugged into the hole to contain a hematoma - minimal. 9. Biopsy should be taken from the periphery of the lesion, which contains the most viable tissue.Biopsy material may be sent for M/C/S if in doubt regarding infection
55 If hole must be made in bone during biopsy, defect should be round to minimize stress concentration, which could lead to pathological fracture
56 Examples of poorly performed biopsies Biopsy resulted in irregular defect in bone, which led to pathological fracture
57 Tumour Biopsy Principles 4 10. A frozen section should be sent intraop to ensure that diagnostic tissue has been obtained.If a tourniquet has been used it should be deflated and meticulous haemostasis ensured before closure.11. Drains should not be used routinely.If a drain is used, it should exit in line with the incision.The wound should be closed tightly in layers.12. operating surgeon should accompany specimen to pathologist if feasibleDiscuss with the pathologist about clinical findings, imaging, intraop findings and the specimen
58 Example of poorly performed biopsy Drain site was not placed in line with incision
59 Principles of management Multidisciplinary team approachBenign asymptomatic tumorsIf certain observeIf in doubt biopsyBenign symptomatic or enlarging tumorsBiopsyExcision/ curretageSuspected malignant tumorsIf primary admit for work-upStagingChoices; amputation, limb sparing surgery, adjuvant therapy
70 Malignant Tumors of Bone OsteosarcomaChondrosarcomaEwing sarcomaChordomaAdamantinomaMalignant vascular tumorsMalignant fibrous histiocytoma and fibrosarcomaMultiple myeloma and plasmacytomaLymphomaMetastatic carcinoma