Tumors and infections Flashcards
3-30 years
Benign, MC in femur and tibia
XR: Lytic, well-defined, lobulated margin with cortex intact
nonossifying fibroma
Night pain w/ response to NSAIDs, self-limited
Benign, MC in long bones and posterior elements of spine
XR: sclerotic, with small <1 cm lucent nidus, cortex not intact
CT: distinct nidus
non-surgical
osteoid osteoma
Dull ache NOT relieved by NSAIDs
Benign and progressive, the “big brother” of osteoid osteoma,
MC in metaphysis of long bones and posterior elements of spine
XR: radiolucent nidus >2 cm - lytic, sclerotic, or mixed
surgical
osteoblastoma
Bone arising from stalk (pedunculated)
Childhood and young adult
Benign - metaphysis of long bone
XR: “Bump” on bone
osteochondroma
Benign growth of any bone
Lytic, bone expansion
XR: ground glass appearance
fibrous dysplasia
Benign, distal femur and tibia
XR: radiolucent, well-defined, confined to cortex w/ sclerotic border
fibrous cortical defect
Benign - commonly in distal femur, proximal tibia, distal radius, proximal humerus, pelvis, sacrum
XR: lytic lesion that may erode beyond cortex and can metastasize to lungs
giant cell tumor
Benign vascular tumor of bone in vertebral bodies, cranio-facial bones
XR: “honey-comb” appearance with vertical striations or “jail bar” appearance
hemangioma
Hypercalcemia, bone pain in back, hips, ribs, spinal cord compression, pathologic fractures
Anemia, bone pain, kidney disease, infection
Hyperviscosity syndrome → mucosal bleeding, vertigo, nausea, visual disturbances, alterations in mental status, hypoxia
multiple myeloma
bones BREAK
B - bone pain (most common)
R - recurrent infections
E - elevated calcium
A - anemia
K - kidney injury
~65 years, men, African Americans, <40
Proliferation of plasma cells in bone – prone to infection, vaccinate!
multiple myeloma
+ Bence Jones proteinuria
PE: pallor, bone tenderness, soft tissue masses, neurologic signs w/ neuropathy or spinal cord compression, fever w/ infection, oliguria (peeing)
Lab: anemia (rouleaux formation), hallmark = paraprotein in serum or urine protein electrophoresis (PEP) or immunofixation electrophoresis (IFE)
Monoclonal spike in gamma or beta regions
multiple myeloma
Radiographs: lytic “punched out” lesions (skull, spine, proximal long bones, ribs), osteoporosis, MRI/ PET/CT scans
Diagnosis = analysis of serum protein electrophoresis and free light chains + bone marrow biopsy
multiple myeloma
How do you treat multiple myeloma?
chemo
Malignant - may have pulmonary metastasis - distal femur, proximal tibia, proximal humerus
spiky, spiculated on XR
osteosarcoma
sudden onset of high fever, chills, pain, tenderness of involved bone
Older patients = low grade fever, worsening bone pain, neurologic abnormalities
hematogenous osteomyelitis
DM, IV catheters, indwelling urinary catheters
IV drug users, sickle cell anemia, older patients
IV drug user - staph
Sickle cell anemia - salmonella, staph (rapid progression to abscess)
Older patients - MC thoracic and lumbar vertebral bodies
Bacteremia, progressed to the blood
hematogenous osteomyelitis
Localized signs of inflammation
High fever and other signs of toxicity usually absent
Septic arthritis and cellulitis can spread to contiguous bone
RF: surgery, trauma, joint replacement
contigious osteomyelitis
Staph aureus and staph epidermidis introduction of bacteria in soft tissue and evolves into bone
Contiguous osteomyelitis
Commonly foot and ankle; hip and sacrum from pressure; bone pain often absent or muted by associated neuropathy
Fever ABSENT;
BEST BEDSIDE CLUES: ability to advance a sterile probe to bone through a skin ulcer
>2cm x 2 cm ulcer
RF: stasis dermatitis
vascular insufficiency
vascular insufficiency osteomyelitis
CULTURES:
Isolation of organism from blood, bone, contiguous focus
Blood cultures (60%)
ESR and CRP elevated
Bone biopsy and culture indicated if blood cultures are negative
Cultures from overlying wounds, ulcers, etc
IMAGING:
#1 -X Ray - soft tissue swelling, tissue planes, periarticular demineralization of bone;
2 weeks after onset: erosion of bone, alteration of cancellous bone, periostitis
#2 CT is more sensitive and can help localize associated abscesses;
Bone scan/gallium scan useful in identifying or confirming site of bone infection
MRI when epidural abscess is suspected
US to diagnose effusion with joints and extra-articular soft tissue fluid (allows to collect fluid but NOT useful for detecting bones)
osteomyelitis dx
How do you treat osteomyelitis?
IV cefazolin, nafcillin, oxacillin
MRSA: IV vancomycin or daptomycin
Can shorten course of IV therapy by 2 weeks of IV therapy with oral regimens
Levofloxacin or cipro AND rifampin
For 4-6 weeks following 2 weeks of IV therapy
MRSA = bactrim, doxycycline, clindamycin
surgery for osteomyelitis if
Staphylococcal osteomyelitis with epidural abscess and spinal cord compression
Other abscesses (psoas, paraspinal)
Extensive disease
Recurrent or persistent infection
1-4 days of migratory polyarthralgias then ½ patterns;
Tenosynovitis of wrists, ankles, toes
Purulent monoarthritis of knee, wrist, ankle, elbow
Fever, GU complaints
Asymptomatic skin lesions (necrotic pustules on palms/soles)
Healthy
Women > men
Rare > 40
MSM
gonococcal arthritis
Elevated WBC
Synovial fluid aspiration
Urethral, throat, cervical, rectal cultures
Urinary NAAT w/ excellent sensitivity/specificity for N/ gonorrhoeae
gonococcal arthritis
gonococcal arthritis tx
IM ceftriaxone
Change to oral agent to complete 7 day course
Responds to abx, no drainage needed
MRSA oral
bactrim
clindamycin
doxycycline
MRSA IV
vancomycin or daptomycin
MSSA oral
cephalexin, dicloxacillin
MSSA IV
cefazolin
oxacillin
nafcillin
