BENIGN TUMORS & TUMORS LIKE

LESIONSDR. ATIF SHAHZAD

PGR ORTHOPEDIC DEPARTMENTSHL

A benign tumor is a mass of cells that lacks the ability to invade neighboring tissue or metastasize.

They mostly occur within the first three decades of life.

The precise incidence is not known because many benign lesions are not biopsied.

They outnumber malignant tumors by at least several hundredfold.

Timely, accurate diagnosis allows appropriate treatment so that the patients can not only survive, but also maintain optimal function of the affected body parts.

INTRODUCTION

Mostly classified according to the normal cell or tissue of origin.

Lesions that do not have normal tissue counterparts are grouped according to their distinct clinicopathologic features.

Overall, matrix-producing and fibrous tumors are the most common.

Among the benign tumors, osteochondroma and fibrous cortical defect are most frequent.

CLASSIFICATION

Bone-forming tumors: Osteoid osteoma

Bone island

Cartilage lesions: Chondroma

Osteochondroma

Fibrous lesions: Nonossifying fibroma

Cortical desmoid Benign fibrous histiocytoma Fibrous dysplasia Osteofibrous dysplasia Desmoplastic fibroma

Cystic lesions: Unicameral bone cyst

Aneurysmal bone cyst Intraosseous ganglion cyst Epidermoid cyst

Fatty tumors: Lipoma

Vascular tumors: Hemangioma

Other Nonneoplastic lesions: Paget disease

“Brown tumor” hyperparathyroidism Bone infarct Osteomyelitis Stress fracture

CLASSIFICATION:

Clinically, present in various ways. The more common benign lesions are

frequently asymptomatic and are detected as incidental findings.

Many tumors, however, produce pain or noticed as a slow-growing mass.

Sometimes, the first hint of a tumor's presence is a sudden pathologic fracture.

CLINICAL PRESENTATION

Radiographic analysis plays an important role in diagnosing bone tumors.

Exact location and extent of the tumor. It can detect features that help limit the

differential diagnosis and give clues to the aggressiveness of the tumor.

Ultimately, in most instances, biopsy and histological study are necessary.

DIAGNOSIS

FIBROUS TUMORS

• Nonossifying fibroma (fibrous cortical defects) is a common developmental abnormality due to proliferation of fibrous tissue.

• 35 % of Children• Mostly asymptomatic and an incidental finding

with or without a fracture.• Approximately 5% of all investigated benign

bone tumors.• Primarily in first 2 decades . Boys > Girls.• Generally, these latent lesions occur in the

metaphyseal region of long bones ;• 40% in distal femur,• 40% in proximal tibia, • 10% in fibula.

NON-OSSIFYING FIBROMA

• A well-defined lobulated

solitary lesion located eccentrically in the metaphysis.

• Multilocular appearance or ridges in the bony wall, sclerotic borders, erosion of the cortex.

• There is no periosteal reaction.

• May occur as a multifocal lesion. 

• The radiographic appearance is always typical, and no additional imaging and biopsy is warranted

RADIOLOGICAL FINDINGS

• Spindle-shaped cells distributed in a whorled pattern.

• There is fibroblastic proliferation with high cellularity.

• Giant cells and foam cells are almost always apparent.

• Usually no bone formation

MICROSCOPY

Chondromyxoid Fibroma Fibrous Dysplasia Infection

DIFFERENTIAL DIAGNOSIS

Radiological findings Biopsy & Histopathology

DIAGNOSIS

Mostly asymptomatic and regress spontaneously in adulthood.

Most pathological fractures can be treated conservatively.

Curettage and bone grafting for lesions that significantly cause weakening the bone.

Large symptomatic lesions, subjected to repeated trauma require treatment with Internal fixation & bone grafting.

Recurrence after treatment is rare.

TREATMENT

• A benign disorder characterized by tumor-like proliferation of fibro-osseus tissue.

• A developmental abnormality of bone. • The hallmark is replacement of normal bone and

marrow by fibrous tissue and small, woven spicules of bone.

• Occur in the epiphysis, metaphysis, or diaphysis.• Latent, active and aggressive features.• Occurs in younger age .• M:F =1:1and 15% of all benign bone tumors.• Mutations of the Gs alpha gene leading to over

activity of adenylyl cyclase have been identified in patients.

FIBROUS DYSPLASIA

• Three clinical presentations exist: Monostotic fibrous dysplasia 70%Polyostotic fibrous dysplasia 25%McCune-Albright syndrome 2-5%

• McCune-Albright syndrome refers to polyostotic fibrous dysplasia, cutaneous pigmentation, and endocrine abnormalities.

PRESENTATION

Pain with complete pathologic fracture or micro-fracture Swelling with pathologic fracture. Commonly presents as a long lesion in a long bone. The ipsilateral proximal femur is invariably affected,

especially proximal femur-varus deformity (Shepherd's crook deformity) affects hip motion, especially abduction, may result in limp.

Limb length discrepancy.  Associated abnormalities, such as sexual precocity,

abnormal skin pigmentation, intramuscular myxoma, and thyroid disease, may be present.

PRESENTATION

• Appearance is characteristic, witch is lucent purely lytic having a granular, ground-glass appearance.

May also contain cystic parts, calcifications and ossifications.

Thinning of the cortex and endosteal scalloping.

Bone expansion and bone deformity (shepherd's crook �deformity ) involving one end to the other.

Tiny trabeculae are noted within the lesion.

RADIOLOGICAL FINDINGS

CONT……..

Variably cellular fibrous tissue containing irregularly shaped trabeculae of woven bone

Woven bone is immature bone that has not undergone remodelling into lamellar bone.

Fibroblasts, with few mitoses.

Bone appears to arise directly from fibrous tissue, not from osteoblasts; termed "Chinese characters" because of unusual shape.

MICROSCOPY

Serum alkaline phosphatase Plain X-Rays Bone Scan CT Scan MRI Occasionally, biopsy is necessary to

establish the diagnosis.

INVESTIGATIONS

Monostotic lesions: Unicameral bone cyst Aneurysmal bone cyst Nonossifying fibroma Giant cell tumor Infection

Polyostotic lesions: Multiple enchondromatosis (Ollier's

disease) Paget's disease Brown tumor of hyperparathyroidism

DIFFERENTIAL DIAGNOSIS

Clinical findings Radiological findings Biopsy

DIAGNOSIS

• Therapy determined by patient's age, activity of lesion, extent of fracture risk, and mechanical deformity

• Conservative therapy: Bracing and modification of activity.

Treatment with bisphosphonates is beneficial for patients with extensive disease.

TREATMENT

• Surgical treatment :

Indicated when significant deformity or pathological fracture occurs or significant pain exists.

• Symptomatic lesions can be treated by closed methods (splinting), curettage and bone grafting, internal fixation, and wide excision .

• Actual and impending pathological fractures are best treated with intramedullary fixation when possible.

• Because recurrence rates are high after curettage and bone grafting, cortical bone grafts are preferred over cancellous grafts (or bone graft substitutes) because of their slower resorption.

• Deformities are corrected by osteotomy with internal fixation.

Pathologic fracture Progressive deformity in weight-bearing bones. Painful stress fractures in femoral neck Although dysplastic bone heals at normal rate

after fracture, resulting callus also dysplastic and disease persists.

Transform to sarcoma (most commonly osteosarcoma, fibrosarcoma of bone)

Third most common cause of osteosarcoma arising in diseased bone after Paget's and radiation-induced osteosarcoma

COMPLICATION

Malignant degeneration is rare,0.5% to 1%. When malignant degeneration occurs, it is usually

in fibrous dysplasia that has received irradiation. Do not irradiate the bone lesions of fibrous

dysplasia.

PROGNOSIS

• Osteofibrous dysplasia (ossifying fibroma of long bones, also known as Campanacci disease) is a rare lesion usually affecting the tibia and fibula.

• Patients usually are in the first two decades of life.

• The middle third of the tibia is the most frequently affected location.

• Usually diaphyseal, it may encroach on the metaphysis.

• Pain usually is absent, unless pathological fracture has occurred.

OSTEOFIBROUS DYSPLASIA

• RADIOLOGY:

• The radiographs show eccentric intracortical osteolysis with expansion of the cortex.

HISTOLOGY:

• Loose fibrous tissue in the center of the lesion and a band of bony trabeculae rimmed by active osteoblasts at the periphery.

• The lesion must be distinguished from monostotic fibrous dysplasia

DIAGNOSIS

The natural course is unpredictable. Some lesions regress spontaneously during

childhood; most progress during childhood, but not after puberty.

Recurrence rates are high after curettage or marginal resection in children.

Conversely, recurrence rates are low after surgery in skeletally mature patients.

Pathological fractures can be treated nonoperatively.

Surgical management is aimed at preventing or correcting deformity.

TREATMENT

FATTY TUMORS

Intraosseous lipoma is a relatively rare lesion, in contrast to its soft-tissue counterpart.

The true incidence is unknown because most are asymptomatic and never come to medical attention.

Most intraosseous lipomas are discovered as incidental findings.

LIPOMA

• The radiographic appearance varies, usually appear as well-defined lucencies possibly with a thin rim of reactive bone.

• CT and MRI show well-defined lesions with the same signal characteristics as fat.

• Central necrosis or calcification sometimes is evident.

• Biopsy rarely is necessary because imaging usually is diagnostic.

DIAGNOSIS

CONT……

Surgery is indicated only for the rare symptomatic lesion. In these cases, simple curettage usually is curative.

TREATMENT

VASCULARTUMOR

Hemangioma is a common benign bone lesion.

It is estimated that 10% of the population has asymptomatic lesions of the vertebral bodies.

Common in the skull & vertebrae, relatively uncommon in long bones of the extremities.

Discovered as incidental findings. Spinal lesions rarely are symptomatic unless

there is vertebral collapse or, in rare cases with soft-tissue extension, nerve root or cord compression.

HEMANGIOMA

RADIOLOGY: Appearance in the spine

usually is characteristic, with thickened, vertically oriented trabeculae giving the classic “jailhouse” appearance.

On CT Scan cross section, these thickened trabeculae have a “polka dot” pattern.

On MRI, the lesions usually are bright on T1- and T2-weighted images.

HISTOLOGY: Rarely needed, reveals a

proliferation of normal-appearing blood vessels.

DIAGNOSIS

• Usually is not necessary; however, multiple options exist for symptomatic lesions.

• Nerve root or cord decompression with spinal stabilization for rare cases of vertebral collapse with neurological compromise.

• Most lesions of the long bones can be treated adequately with extended curettage.

• Preoperative embolization minimize intraoperative blood loss, which otherwise could be massive.

• Selective arterial embolization can be used as definitive treatment in surgically inaccessible locations.

• Low-dose radiation is an option for inoperable lesions but carries the risk of malignant degeneration.

TREATMENT

NON NEOPLASTIC LESIONS

Paget’s disease of bone is a localized disorder of bone remodeling, characterized by enhanced resorption of bone by giant multinucleated osteoclasts followed by formation of disorganised woven bone by osteoblasts.

The resultant bone is expanded, weak and vascular, causing bone pain brittleness and deformity.

Paget’s disease is a disorder of uncertain origin. This disease can occur any where but is most

common in the pelvis, skull, the hip and the bones of the legs.

PAGET’S DISEASE

Paget disease may affect 4% of people of Anglo-Saxon descent who are older than age 55 years, but it is rare in most other populations.

It is a disorder of unregulated bone turnover.

Excessive osteoclastic resorption is followed by increased osteoblastic activity.

An early lytic phase is followed by excessive bone production with cortical and trabecular thickening.

CONT….

• Radiographic findings depend on the stage of the disease.

• In the lytic phase, bone resorption can take on a “blade of grass” or “flame” appearance beginning at the end of the bone and extending toward the diaphysis.

• Later the radiographs show bony sclerosis, thickened cortices, and thickened trabeculae .

• Bone scans usually are “hot”.

DIAGNOSIS

CONT………..

MRI is helpful in this circumstance because the marrow signal in patients with Paget disease usually remains normal.

Histology usually reveals a characteristic “mosaic” pattern with widened lamellae, irregular cement lines, and fibrovascular connective tissue.

CONT…….

Medical Management :Consists of nonsteroidal anti inflammatory

drugs, calcitonin, or bisphosphonates. Serum alkaline phosphatase levels and

urine pyridinium cross-links can be used to monitor the activity of the disease.

Surgical Management :Consists of correcting deformity and

treating pathological fractures. During periods of active disease, intraoperative

bleeding from affected bones can be massive.

TREATMENT

Approximately 1% of patients with Paget disease develop a secondary bone sarcoma, usually an osteosarcoma.

This risk is probably higher for patients with polyostotic disease.

PROGNOSIS

A bony lesion that arises in settings of excess osteoclastic activity, as hyperparathyroidism.

Primary hyperparathyroidism usually is caused by an adenoma of the parathyroid glands.

Secondary hyperparathyroidism can occur in patients with chronic renal failure.

When the disease is discovered early, the skeletal change usually is limited to diffuse demineralization.

May occur in any bone, most frequently centrally in the diaphysis.

Only rarely does the change become markedly focal and produce a “brown tumor” which resembles a giant cell tumor and is difficult to distinguish from it.

BROWN TUMOR

BLOOD CHEMISTRY: The diagnosis should be established by

◦ Serum calcium,◦ Phosphorus, ◦ Alkaline phosphatase, ◦ Parathyroid hormone levels

MICROSCOPY: Some microscopic features in

hyperparathyroidism, (1) the giant cells are a little smaller, often occurring in a nodular arrangement, especially around areas of hemorrhage; (2) the stromal cells are more spindle-shaped and delicate

DIAGNOSIS

• Intense osteoclastic and osteoblastic activity associated with peritrabecular fibrosis.

• Diffuse subperiosteal resorption or generalized demineralization.

RADIOLOGICAL FINDINGS

More extreme focal bone resorption may resembles a primary bone tumor or metastatic lesion.

Borders are sharp on plain radiographs, though non-sclerotic.

May be confused with giant cell tumor when located in the epi-metaphysis.

CONT……

Patients with hyperparathyroidism usually are treated by an endocrinologist. Orthopaedic management consists of treating actual or impending pathological fractures

TREATMENT

Bone infarct refers to ischemic death of the cellular elements of the bone and marrow.

Idiopathic or secondary to other conditions like steroid use, alcoholism, sickle cell anemia.

Bone infarct refers to lesions occurring in the metaphysis and diaphysis of bone.

They also can occur in patients with no other apparent underlying disorder.

BONE INFARCTS

The diagnosis usually by plain radiographs. Bone infarcts usually are well-defined

metaphyseal lesions with irregular borders. The periphery of the lesion is calcified, in

contrast to chondroid lesions, which are usually calcified throughout.

Biopsy (usually unnecessary) shows mineralization of necrotic marrow elements.

Bone scan CT Scan MRI

DIAGNOSIS

TREATMENT:

Bone infarcts usually are asymptomatic, and no treatment is required. If a patient presents with pain, another etiology should be sought.

Rarely, malignancy, such as a malignant fibrous histiocytoma, can occur at the site of a bone infarct.

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