-Symptoms: P ain is worse at night and is relieved with aspirin
- X rays: c entral radiolucency surrounded by a sclerotic rim.
- Micro: s mall ( < 2 cms ) lesion of the cortex with c entral nidus of osteoid surrounded by dense sclerotic rim of reactive cortical bone.
O STEOBLASTOMA : Similar to an osteoid osteoma but larger than 2 cms in size and often involv ing vertebrae.
O STEOCHONDROMA (exostosis)
- Benign bon e metaphyseal grow t hs capped with cartilage that originates from epiphyseal growth plate.
-It may affects a dolescent males as a firm, solitary growth a t the ends of long bones.
-It may be asymptomatic or cause pain, produc ing deformity, and can undergo with malignant transformation ( rare ly )
Benign tumors, Cartilage (cont.)
O STEOCHONDROMATOSIS ( Multiple hereditary exostosis) -Characterized with multiple , often symmetric, osteochondromas.
E NCHONDROMA : b enign cartilaginous growth within the medullary cavity of bone, usually involving the hands and feet.
-Is a t ypical solitary lesion often asymptomatic and require no treatment.
Benign tumors. Cartilage
M ULTIPLE ENCHONDROMAS (Enchondromatosis)
O LLIER DISEASE : a n on hereditary s yndrome, with multiple enchondromas in hands and feet.
It may p resents with pain and spontaneous Fxs
It m ay undergo malignant transformation to chondrosarcoma.
Benign tumors. Cartilage (cont.)
M AFUCCI SYNDROME
Soft tissue hemangiomas
Increased risk of malignant transformation, ovarian Ca . and brain gliomas.
Maffucc i Syndrome www.freelivedoctor.com
Maffucci Syndrome www.freelivedoctor.com
Malignant Tumors of Bone.
O STEOSARCOMA ( Osteogenic sarcoma)
- Most common primary malignant tumor of bone
- Males> females. Most occur in teenagers ( ages 10-25)
- Patients with familial retinoblastoma have a high risk
- Clinical features: l ocalized pain and swelling
Malignant tumors of bone OSTEOSARCOMA(cont.)
Classic X ray findings: - Codman’s triangle ( periosteal elevation)
- Sunburst pattern
- Bone destruction
- Grossly: o ften involves the metaphyses of long bones , usually around the knee (distal femur/pro
ximal tibia.) and it may be seen as a large, firm,
white mass with necrosis and hemorrhage.
Malignant Tumors of Bone .Osteosarcoma
Micro: Anaplastic cells producing osteoid and bone.
T x : s urgery / chemotherapy
Prognosis: p oor (h ematogenous metastastasis to the lungs is a common complication)
“ SECONDARY” OSTEOSARCOMAS . Occur in elderly persons, associated with Paget’s disease, irradiation and chronic osteomyelitis
Malignant tumor of cartilage
- Males> females age 30-60
-T umor may arise primarily or secondary to a preexisting enchondroma,exostosis or Paget’s disease.
- Clinical presentation: progressively e nlarging mass with pain and swelling, that typically involves the pelvic bones, spine, and shoulder girdle.
- Micro: composed of atypical chondrocytes and chondroblasts, often with multiple nuclei in a lacuna r structure
G IANT CELL BONE TUMOR (Osteoclastoma)
Uncommon malignant neoplasm containing multinucleated giant cells admixed with stromal cells. Females>males, with ages between 20-50 years
Clinical features : b ulky mass with pain and Fx.
X rays : e xpanding lytic lession surrounded by a thin rim of bone.
It m ay have also a soap bubble appearance
Gross: o ften involves the epiphyses of long bones, usually around the knee ( distal femur and proximal tibia) seen a r ed brown mass with cystic degeneration.
G IANT CELL TUMOR(cont.)
Micro: m ultiple osteoclast-like giant cells that are distributed within a background of mononuclear stromal cells.
T x : s urgery / curetage or bloc k resection
Prognosis: locally aggressive with a high rate of recurrence.
Giant cell tumor www.freelivedoctor.com
E WING SARCOMA
Malignant neoplasm of undifferentiated cells arising within the marrow cavity M ales are affected slightly more often than females, most occur in teenagers ( 5-20)
Clinical features : pain , swelling and tenderness
Classic translocation t11;22 which produces the EWS- FL11 fusion protein
X - ray : concentric onion skin layering of new pe r iosteal bone.
Ewing sarcoma www.freelivedoctor.com
E WING SARCOMA(cont.)
Gross: o ften affects the diaphyses of long bones with most common sites like femur, pelvis and tibia seen a w hite tan mass with necrosis and hemorrhage.
Micro: s heets of undifferentiated small round blue cells resembling lymphocytes.
Characteristic Homer - Wright pseudorosettes
Frequently the t umor al cells erode cortex and periosteum and invade surrounding tissues.
Tx.: c hemotherapy, surgery and / or radiation
Prognosis: 5 year survival rate of 75%
The “motor unit”consists of a lower motor neuron(anterior horn cell or neuron in cranial nerve nuclei), its axon and the muscle fibers innervated by it. The number of muscle fibers innervated varies from a few fibers(oculo-motor muscles) to several hundreds(extremity muscles). Muscles fibers of one motor unit are scattered in a wide area in a random fashion(“checkerdboard”).
Diseases can be classified as involving: A. Motor neuron B. Peripheral nerves C.Neuro muscular junction D. Muscles
A. DISEASES OF MOTOR NEURON. -Etiology of most of the motor neuron dis.(AML, progressive muscular atrophy) is not known, but may be caused by several agents: adriamycin, vincristine, aluminium perikaryon(neuronal cell body) primarily affected w/loss of microtubules and nuclear displacement + increased cytoplasmic neurofilaments or tangled masses of neurofila- ments. Viral infections(Polyomyelitis, Herpes encephalitis, Varicella-zoster) may also affect the motor neuron or sensory ganglia.
B. DISEASES OF PERIPHERAL NERVES I. Axonal degeneration(axonal neuropathy) a. Wallerian degeneration(crush/cut along a myelinated fiber) b. Axonal degeneration caused by other diseases (less axoplasm leakage+ more inflammation + chronic evolution): 1.Proximal axonal degeneration: intoxic. w/ IDPN(BB-Iminodipropionitrite) shrinkage of distal axons due to focal proximal blockage. 2.Distal axonal degeneration: earliest changes occur in the most distal portion of axons
DISEASES OF PERIPHERAL...(cont.) Many diseases w/earlier changes in the most distal portion of axons slow spread to proximal structures perikaryon cannot support the terminal axon, vgr.: --Hereditary neuropathies. -HSMN I (Charcot-Marie-Tooth)disease, the MOST common of these, inherited as autosomal- dominant is usually present in childhood/early adulthood(PMP 22 gene/17p11.2-p12 locus), characterized by progressive atrophy of leg mus- cles,foot drop/deformed feet w/less sensory defect
DISEASES OF PERIPHERAL...(cont.) --Hereditary neuropathies... -HSMN II(CMT2A) also AD, with similar manifestations than CMT I but without nerve enlargement and presentation at a la- ter age. Linked to chromosome 1p35-p36. -HSMN III(Dejerine-Sottas disease) is an AR condition that begins slowly in early childhood w/delayed acquisition of motor skills and involvement of muscles of limbs and trunk enlar gement of nerves easy to detect. Genetic heteroge nicity(PMP 22, MPZ, PRX and EGR2).
DISEASES OF PERIPHERAL...(cont.) --Acquired metabolic/toxic neuropathies. -Diabetic peripheral neuropathy: w/symme tric neuropathy involving distal sensory/mo tor nerves + dysfunction of autonomic nervous system(20-40% of cases).It can also present as a single peripheral or cranial neuroneuropathy(oculomotor nerve). -Metabolic/nutritional: chronic liver disease,resp. insuff., renal failure, thiamine def.,Vit.B12,B6,E. Chronic alcoholism, etc.
S TRIATED MUSCLE DISORDERS ( Dystrophies, Myositis and Tumors )
P OLYMYOSITIS :
It may affect a dults, females with bilateral progressive, proximal muscle weakness
Micro: e ndomysial lymphocytic inflammation ( mostly cytotoxic T8 )
Skeletal muscle fiber degeneration and regeneration.
It may affect c hildren or adults, females, with bilateral and proximal muscle weakness
Also: s kin rash of the upper eyelids , periorbital edema
Micro: p erimysial and vascular lymphocytic inflammation
with p erifascicular fiber atrophy
Skeletal muscle fiber degeneration and regeneration.
Increased risk of lung, stomach, ovarian and breast cancers.
M USCULAR DYSTROPHIES
DUCHENNE MUSCULAR DYSTROPHY
MOST COMMON and severe form of muscular dystrophy.
X linked inheritance
Dystrophin gene in Xp 21
( Mutation results in a virtual absence of dystrophin protein )
Normal at birth with onset of symptoms by age 5 , with progressive muscular weakness of proximal , shoulder and pelvic girdles.
C ALF PSEUDOHYPERTROPHY
Heart failure and arrhytmias may occur
Progressive r espiratory failure and pulmonary infections
Increased serum creatine kinase
Muscle fibers of various sizes , necrosis, degeneration and regeneration fibers
Duchenne muscular dystrophy
D x : m uscle biopsy with immunostains show s decreased dystrophin protein