Bone, Joints, and Soft Tissue Tumors Flashcards
what are the two main components of bone
mineral (inorganic) component (65%)
osteoid (organic) component (35%)
what is osteopontin
extracellular structural protein that helps with bone formation
what role does the inorganic bone matrix play
gives rigidity and hardness to bone
what role does the organic bone matrix play
collagen fibers gives bone its tensile strength
what are the three main bone cells
osteoblasts
osteocytes
osteoclasts
what do osteoblasts do
build bone
what do osteocytes do
regulate calcium and phosphate levels
what do osteoclasts do
responsible for bone resorption
what is the difference between woven and lamellar bone
woven (left): cellular and disorganized (fetal)
lamellar (right): organized collagen (adult)
long bones develop through this process
endochondral ossification
how does endochondral ossification work
chondroclasts remove central portion of bone to make medullary cavity while osteoblasts deposit bone in the diaphysis and at growth plate
produces radial growth of bone
what are the five zones of a growth plate starting from the exterior
1.) reserve zone
2.) zone of proliferation
3.) zone of hypertrophy
4.) zone of mineralization
5.) primary spongiosa
flat bones develop through this process
intramembranous ossification
how does intramembranous ossification work
osteoblasts deposit new bone on the preexisting surface (appositional growth)
when is peak bone mass achieved
early adulthood after the cessation of skeletal growth
what is dyostosis
localized disruption of migration and condensation of mesenchyme
what are the three most common forms of dyostosis
1.) absence of bone or digit (aplasia)
2.) extra bones or digits (supernumerary digit)
3.) abnormal fusion of bones (syndactyly)
what is dysplasia
genetic systemic disorganization of bone and/or cartilage
ex. osteogenesis imperfecta
which gene mutation commonly causes developmental disorders of bone and cartilage
FGFR3
how do defects in nuclear proteins and transcription factors affect bone and cartilage
leads to abnormally developed bones
what is the most common skeletal dysplasia and a major cause of dwarfism
achondroplasia
what is achondroplasia
short stature, large head
does not usually cause life threatening side effects
what is the most common cause of achondroplasia
sporadic mutations in the paternal allele (90%)
which mutation is involved in achondroplasia
FGFR3
what is the most common form of dwarfism
thanatophoric dysplasia
what is thanatophoric dysplasia
underdeveloped thoracic cavity leads to respiratory issues and death
which mutation is involved in thanatophoric dysplasia
FGFR3
what is osteogenesis imperfecta (brittle bone disease)
a type 1 collagen deficiency disease
affects bone, joints, eyes, ears, skin, and teeth
what is a common sign of osteogenesis imperfecta (brittle bone disease)
blue sclera - thin scleral collagen allows choroid vasculature to be seen
what is osteopetrosis (marble bone disease)
reduced bone resorption due to issues with osteoclasts
leads to increased bone density as new, poor bone is being put down
what are the two other names for osteopetrosis
marble bone disease
albers-schonberg
what is a common sign of osteopetrosis
Erlenmeyer flask bone deformity
what is mucopolysaccharidoses
lysosomal storage disease
lack of certain enzymes leads to accumulation of mucopolysaccharides in chondrocytes
accumulation causes apoptosis and death of cells
leads to deformities of cartilage
what is osteopenia
decreased bone mass (-1 to -2.5 SD)
what is osteoporosis
severe osteopenia (-2.5 SD)
increases risk for fractures and compression
what are the five main causes of osteoporosis
1.) increasing age
2.) reduced physical activity
3.) genetic factors
4.) lack of calcium
5.) hormones
what is seen histologically in someone with osteoporosis
decreased amount of bony spicules
which class of drugs is used to treat osteoporosis
bisphosphonates - reduce osteoclast activity
what is the main cause of osteomalacia and rickets
deficiency in vitamin D
what is rickets
disorder in children due to lack of vitamin D
interferes with the deposition of bone in the growth plates
what is osteomalacia
disorder in adults due to lack of vitamin D
bone that is formed is unmineralized, making it soft and easy to fracture
which hormone is important for regulating calcium
parathyroid hormone (PTH) - causes increased osteoclast activity
what is the most common cause of hyperparathyroidism
parathyroid adenoma
osteoporosis mostly affects which three parts of the body
1.) phalanges
2.) vertebrae
3.) proximal femur
what is osteitis
inflammation of bone due to osteoclasts tunneling into spicules
what is a brown tumor
reactive bone lesion formed due to osteoclast activity heightened by hyperparathyroidism
what are the three main consequences of the bone due to hyperparathyroidism
1.) osteoporosis
2.) osteitis
3.) brown tumor
what is renal osteodystrophy
skeletal changes that occur in chronic renal disease and dialysis
what is Paget disease (osteitis deformans)
increased bone mass due to new bone that is abnormally shaped, weak, and brittle
leads to a thickened cortex
what are the three phases of Paget disease (osteitis deformans)
1.) initial - osteolytic phase (breakdown)
2.) mixed osteoclastic and osteoblastic stage (build up)
3.) final - osteosclerotic stage (bone doesn’t solidify)
what would you see histologically in someone with Paget disease (osteitis deformans)
mosaic pattern of lamellar bone
in which condition would you see a mosaic pattern of lamellar bone
Paget disease (osteitis deformans)
what is simple fracture
fracture where the overlying skin is intact
what is a compound fracture
fracture where the bone touches the skin surface
what is a comminuted fracture
bone is fragmented
what is a displaced fracture
the two ends of the bone are misaligned
what is a stress fracture
crack like fracture due to repetitive loads
what is a greenstick fracture
fracture extending only partially through the bone
which type of fracture is most common in children
greenstick - due to their soft bones
what is a pathologic fracture
bone is weakened by an underlying disease such as a tumor and then fractures
how long does it take a fracture to heal completely
3 weeks to months
what is a large component of impeded healing of fractures
smoking
what is avascular necrosis (AVN)
infarction of bone and marrow typically due to fractures or corticosteroids
cartilage begins to lift away from bone’s surface
what are the two things seen grossly in the case of avascular necrosis (AVN)
wedge-shaped subchondral infarct
separation of cartilage from bone
what is osteomyelitis
inflammation of bone and marrow
what is pyogenic osteomyelitis
inflammation of bone and marrow most commonly caused by hematogenous spread of staph. aureus
dead, necrotic bone in association with osteomyelitis is known as this
sequestrum
how does osteomyelitis spread in infants
spreads through cartilage or into a joint
what is tuberculous spondylitis (pott disease)
tuberculosis within the vertebral column
what is congenital syphilis
syphilis acquired from birth
spirochetes gather in areas of active ossification which leads to bowing of bone (saber shin)
saber shin is seen in which condition
congenital syphilis
what is the age range for developing most bone tumors
0-30 years of age
what is the most common primary bone tumor
osteosarcoma
which two conditions can increase your risk of a bone neoplasm
chronic osteomyelitis
Paget disease
what are the two main types of benign bone forming tumors
osteoid osteoma
osteoblastoma
what is an osteoid osteoma
benign bone tumor
less than 2 cm
common in men
causes thickening of cortex
mostly affects femur or tibia
what is an osteoblastoma
benign bone tumor
greater than 2 cm
mostly affects the spine
causes deformation
what is an osteoid osteoma lesion called
nidus
what is the most common primary malignant tumor of bone
osteosarcoma
who, men or women, are more at risk for osteosarcoma
men
where do osteosarcomas most commonly arise from
metaphysis region of long bones of the extremities - knee specifically
what is a common feature of osteosarcomas
codman triangle
which gene mutation is most responsible for osteosarcomas
TP53
what are the three most common metastasis locations of osteosarcoma
1.) lungs
2.) bone
3.) brain
what are the three main types of cartilage
hyaline (myxoid)
fibrocartailge
elastic
what is the most common benign bone tumor
osteochondroma (exostosis)
what is the most common form of osteochondroma (exostosis)
solitary
what is an osteochondroma (exostosis)
benign cartilage capped tumor that is attached to underlying skeleton by bony stalk
develop in long bones
who, males or females, are most affected by osteochondromas (exostosis)
males (x3)
what is multiple hereditary exostosis syndrome
multiple osteochondromas that occur closer to the growth plate
what is a chondroma
benign tumor of hyaline cartilage
what is the most common type of intraosseous cartilage tumor
chondroma
what are the two main types of chondromas
enchondroma and juxtacortical chondroma
what is an enchondroma
benign tumor of hyaline cartilage that arises within the medullary cavity
what is a juxtacortical chondroma
benign tumor of hyaline cartilage which arises on the surface (cortex) of the bone
which two conditions are associated with enchondromas
Ollier disease and Maffucci syndrome
those with Maffucci syndrome are at risk for developing which two types of malignancies
ovarian carcinomas and brain gliomas
what is a chondrosarcoma
malignant tumor of cartilage that typically affects men over 40
what are the four histologic classifications of chondrosarcomas
1.) hyaline cartilage producing (conventional tumor)
2.) clear cell
3.) differentiated
4.) mesenchymal variants
what are the two main sites of chondrosarcomas and which is most common
central (intramedullary) and peripheral (juxtacortical)
higher grade chondrosarcomas have which histologic feature
binucleation (dividing nuclei) of chondrocytes
what is a Ewing sarcoma
malignant bone tumor that arises in the medullary cavity
Ewing sarcoma is grouped with which other condition into a single category
primitive neuroectodermal tumor (PNET)
where is the gene mutation for Ewing sarcoma located
translocation of the EWSR1 gene on chromosome 22
what is the important histologic feature of a primitive neuroectodermal tumor
Homer-Wright rosettes
Homer-Wright rosettes are commonly seen in which condition
primitive neuroectodermal tumors
which is seen histologically in Ewing sarcoma
sheets of small round uniform cells
what is important to note when grossing a Ewing sarcoma specimen
quantifying the amount of chemotherapy-induced necrosis
what is a giant cell tumor of the bone
locally aggressive bone tumor
benign but can metastasize to the lungs
what do you see histologically in a giant cell tumor of the bone
multinucleated osteoclast-type giant cells
how is a giant cell tumor of the bone treated
with curettage
what is an aneurysmal bone cyst (ABC)
benign tumor that develops in the metaphysis of long bones and in the vertebral bodies
what is seen histologically in an aneurysmal bone cyst
multiple blood-filled cystic spaces with osteoclast-type giant cells
how big is a typical non-ossifying fibroma
5-6 cm
what is seen histologically in a non-ossifying fibroma
storiform pattern due to benign spindle cells
what is seen histologically in fibrous dysplasia
lack of osteoblastic rimming
what is the most common cause of a malignant bone tumor
metastasis - not a primary cancer
what are the three metastatic ways of spread to the bone
1.) direct extension
2.) lymphatic/hematogenous
3.) intraspinal seeding (CSF)
metastatic bone tumors in adults mostly come from which four location
1.) prostate
2.) breast
3.) kidney
4.) lung
which five conditions are associated with metastatic bone tumors in children
1.) neuroblastoma
2.) Wilms tumor
3.) osteosarcoma
4.) Ewing sarcoma
5.) rhabdomyosarcoma
what are the two main types of joints
solid (non-synovial)
cavitated (synovial)
what is a solid (non-synovial joint)
provides structural integrity
ex. pubic symphysis
what is a cavitated (synovial) joint
provides a wide range of motion
ex. fingers
which type of joint is associated with rheumatoid arthritis
cavitated (synovial)
what is hyaline cartilage
serves as an elastic shock absorber
made mostly of water but also of type 2 collagen
what is osteoarthritis (degenerative joint disease)
degeneration of cartilage that causes failure of synovial joints
what is the most common type of joint disease
osteoarthritis (degenerative joint disease)
what are 4 things that pose a risk factor for osteoarthritis (degenerative joint disease)
1.) diabetes
2.) less physical activity
3.) infection
4.) obesity
osteoarthritis most commonly affects what in women
hands and knees
osteoarthritis most commonly affects what in men
hips
what are Heberden nodes
prominent osteophytes at the distal interphalangeal joints that are common in women
osteoarthritis (degenerative joint disease) mostly affects which age range of people
those over 70
what are the 4 things seen grossly in osteoarthritis
1.) fibrillation
2.) bone eburnation
3.) subchondral cysts
4.) osteophytes
what is fibrillation
characteristic of osteoarthritis
granular fissures and clefts in the cartilage
what is a bone eburnation
characteristic of osteoarthritis
exposed subchondral bone that appears like polished ivory due to friction
what are osteophytes
characteristics of osteoarthritis
mushroom-shaped bony outgrowths
what is rheumatoid arthritis
autoimmune chronic inflammatory disorder
who, women or men, are most at risk for rheumatoid arthritis
women (x3)
rheumatoid arthritic lesions are most commonly found in which four locations
1.) skin
2.) heart
3.) blood vessels
4.) lungs
what are the four main histologic features of rheumatoid arthritis
1.) synovial cell hyperplasia
2.) angiogenesis
3.) exudate
4.) osteoclastic activity
what is an important feature of rheumatoid arthritis
production of a pannus (mass of synovium, inflammatory cells, granulation tissue, and fibroblasts)
what are rheumatoid subcutaneous nodules
nodules that form in the case of RA in areas subjected to pressure
what is juvenile idiopathic arthritis (JIA)
disorders that present with arthritis in those under 16 years of age
often systemic and affect the large joints
what is ankylosing spondylitis
destruction of articular cartilage and bony fusion of the spine
which two joints are most commonly affected by ankylosing spondylitis
sacroiliac and apophyseal joints
reactive arthritis can be associated with which three conditions
1.) HIV
2.) chlamydia
3.) GI tract infections
what is psoriatic arthritis
chronic inflammatory arthropathy associated with psoriasis
psoriatic arthritis mostly affects which three things
sacroiliac joint, hands, and feet
what is an important feature of psoriatic arthritis
pencil in cup deformity
suppurative arthritis is often associated with which condition
osteomyelitis
suppurative arthritis is seen often in which demographic of people
drug users
viral arthritis is associated with which 4 conditions
1.) rubella
2.) EBV
3.) HCB and HCV
4.) HIV
what is crystal induced arthritis
articular crystal deposits are associated with a variety of acute and chronic joint disorders
what are the two types of crystals that cause crystal induced arthritis
endogenous and exogenous crystals
what are two examples of endogenous crystals
monosodium urate (gout)
calcium pyrophosphate dehydrate (pseudogout)
what are three examples of exogenous crystals
1.) corticosteroid ester crystals
2.) talcum
3.) silicone
gout crystals are made of what
monosodium urate crystals (MSU)
what is the pathognomonic feature of gout
tan-white chalky deposits
what is important in processing gout specimens
do not place in formalin - only use alcohol
what is seen under the polarizing light in a case of gout
needle-like crystals
who, men or women, are more affected by gout
men over 30
gout is associated with which four conditions
1.) alcohol
2.) obesity
3.) renal failure
4.) drugs
pseudogout crystals are made of what
calcium pyrophosphate
what is the histologic appearance of pseudogout
rhomboid crystals
which, benign or malignant, soft tissue tumors are most common
benign
which four conditions are associated with soft tissue tumors
1.) neurofibromatosis 1
2.) gardner syndrome
3.) Li-Fraumeni syndrome
4.) Olser-Weber Rendu syndrome
what are the two types of soft tissue tumors and which is more common
simple
complex
what are the two main types of simple soft tissue tumors
Ewing sarcoma
synovial sarcoma
what are the two main types of complex soft tissue tumors
leiomyosarcomas
undifferentiated sarcomas
what is the most common soft tissue tumor of adulthood
lipoma
what are the 5 subclassifications of lipomas
1.) conventional
2.) fibrolipoma
3.) angiolipoma
4.) spindle cell
5.) myelolipoma
liposarcomas mostly affect which age range
50 to 60 year olds
what are the three histologic subtypes of liposarcomas
1.) well differentiated
2.) myxoid
3.) pleomorphic
what is the histologic appearance of a well-differentiated liposarcoma
fat and spindle cells
what is the histologic appearance of a myxoid liposarcoma
basophilic extracellular matrix and arborizing capillaries
what is the histologic appearance of a pleomorphic liposarcoma
anaplastic cells and lipoblasts
what is nodular fasciitis
proliferation of fibroblasts and myofibroblasts within the soft tissue, usually due to trauma
nodular fasciitis mostly affects which area of the body
upper extremities
superficial fibromatoses mostly affects men or women
men
what are the three main types of superficial fibromatoses
1.) palmar (dupuytren contracture)
2.) plantar
3.) penile (peyronie disease)
deep fibromatoses most commonly affects men or women
women
what is the most common benign primary cardiac tumor in infants and children
rhabdomyoma
what are the four subtypes of a rhabdomyosarcoma
1.) alveolar
2.) embryonal
3.) pleomorphic
4.) spindle cell/sclerosing
which subtype of rhabdomyosarcoma is most common
embryonal
what is seen histologically in an embryonal rhabdomyosarcoma
spindle cells and myxoid stroma
what is seen histologically in an alveolar rhabdomyosarcoma
fibrous septae resembling those in pulmonary alveoli
a leiomyosarcoma is most commonly found in which two areas
extremities and retroperitoneum