Musculoskeletal System Pathology - Walby Flashcards
(286 cards)
1
Q
Osteoprogenitor cells are (toti/pluri)potent
A
pluripotent
2
Q
T/F: osteoprogenitor cells are on all bony surfaces
A
true
3
Q
Where are osteoblasts found?
A
surface of the bone
4
Q
WHere are osteoclasts found?
A
granulocyte precursors of the marrow
5
Q
What cell is in Howship’s lacunae?
A
osteoclasts
6
Q
What bone cells communicate with each other via canaliculi?
A
osteocytes
7
Q
what forms bone matrix?
A
osteoblast
8
Q
what maintains bone tissue
A
osteocyte
9
Q
The periosteum is made of what two layers?
A
outer fibrous
inner osteogenic
10
Q
What type of collagen forms 90 % of the organic component of the bone?
A
Type I collagen
11
Q
Woven bone is seen during what part of dev?
A
fetal skeleton and during repairs from breaks
12
Q
What is the most common disease of the growth plate?
A
achondroplasia
13
Q
what is the histology like in achondroplasia?
A
disorderly laydown of bone
14
Q
Achondroplasia has a mutation in what receptor?
A
Fibroblast growth factor receptor 3 (FGFR3)
15
Q
What is the most common form of Achondroplasia?
A
heterozygous auto dom
16
Q
Describe the physical features of heterzygote Achondroplasia?
A
Infants have shortened extremities, bowing of legs, lordosis (sway-back), relatively normal trunks, and enlarged heads (spares the cranium & vertebrae), frontal bossing, saddle nose
17
Q
T/F: growth hormone helps in the development of homozygous Achondroplasia
A
False
18
Q
What other complications arise in homozygous Achondroplasia?
A
compromised respiratory function (abn chest cavity); die in infancy
19
Q
What is the lifespan in Achondroplasia?
A
normal
20
Q
What is a Lysosomal storage diseases involving acid hydrolases?
A
mucopoplysaccharidoses
21
Q
How does mucopolysaccharidoses manifest physically?
A
Results in abnormalities of hyaline cartilage, and hence growth plates and articular surfaces, due to abnormalities of chondrocytes, and hence growth plates, articular cartilage, etc.
Manifest as chest wall deformities, short stature, and malformed bones
22
Q
Osteogenesis imperfecta is a disease of (bone growth/matrix formation)
A
matrix formation
23
Q
OI is also known as:
A
brittle bone disease
24
Q
OI is caused by a abn. in what type of collagen
/
A
type 1
25
What disease has this presentation?
joints (lax), eyes (blue sclera), ears (deafness), skin (thin), and teeth (small & discolored)
26
What is unique about the eyes in OI?
the sclera is blue
27
Big picture wise, what is the issue in OI?
too little bone; cortical thinning and attenuation of trabecular bone--woven instead of lamellar
28
Which types of OI are most likely to survive?
types I and IV
29
What are the common features of survivors of OI?
hearing deficits
BLUE YELLOW TEETH
fractures
30
What type of OI is this?Perinatal demise (mostly Auto Rec)
II
31
What type of OI is this?
| Postnatal fractures without blue sclerae (Auto Dom)
IV
32
What type of OI is this?
| Postnatal fractures with blue sclerae, deafness (Auto Dom)
I
33
What type of OI is this?
| Progressively deforming w/ growth retardation (Auto Rec)
III
34
Vitamin D deficiency resulting in rickets results in decreased (blank) and an increase in (blank)
decrease in mineralization and an increase in osteoid
35
HyperPTH has what effect on bone?
decreased bone density
36
Osteoporosis has a decreased bone (blank)
density and mass
37
T/F: there is a abn. in the ratio of minerals in the bone in osteoporosis
false
38
What causes localized/focal osteoporosis?
disuse
39
Primary osteoporosis is seen in what age group and sexes?
post menopausal women and senile in old men
40
People from what countries are at risk of developing osteoporosis?
N. european and Asians
41
T/F: Hispanics have a lower risk of osteoporosis compared to europeans
false; similar
42
What race is at the least risk of developing osteoporosis?
african americans
43
excessive consumption of what things can lead to osteoporosis?
```
EtOH
caffeine
carbonated beverages
smoking ciggies
anticonvulsants or benzos long term
```
44
What hormonal imbalances can lead to osteoporosis?
Hypogonadism resulting in reducted testosterone
Hypercortisol states
HyperPTH
Inadequate Ca2+ or Vit. D in diet
45
Plain XRAY doesn't see osteoporosis until what percent of bone is gone?
30-40%
46
T/F: serum calcium and phosphorus are not diagnostic for osteoporosis
true
47
T/F: there is no sensitive or specific test for osteoporosis
true
48
Kyphoscoliosis and lordosis are complications of osteoporosis that arise as a result of fractures in what regions of the spine?
thoracic and lumbar
49
T/F: osteoporosis also shows up as fractrues in the wrist
true
50
Fractures of the femoral neck, pelvis, and spine are complicated by (blank) and pneumonia
PE
51
What is the characteristic appearance of osteoporotic vertebrae?
fish mouth appearance
52
when do we reach our peak bone mass?
3rd decade
53
Where do we lose the most bone mass?
spine and femoral head
54
low calcium intake in what age group and sex predisposes for osteoporosis?
adolescent girls
55
Where is most of the bone resorption coming from in osteoporosis?
cancellous bone
56
what percent of women will have an osteoporotic bone fracture in their life?
1/2
57
How does decreased estrogen lead to increased bone resorption?
increased IL1
increased IL6
recruits osteoclasts and increases bone resorption
58
what is the most potent activator of osteoclasts?
IL1
59
Paget's diseases is caused by (blank) dysfunction
osteoclast
60
What are the three stages of osteoclast dysfunction?
1. otesoclast/osteolytic stage--hypervascularity and bone loss
2. mixed stage with osteoblastic activity
3. burnt-out osteosclerotic stage
61
When does Paget's onset?
5th decade
62
What is the racial predilection of Paget's?
whites of N. europe and US
63
What countries is Pagets rare in?
Scandinavia, China, Japan, and Afrika
64
What is the histological change in the osteoclasts in Pagets?
become multinucleate
65
In Pagets, the marrow is replaced by (blank)
CT containing osteoprogenitor cells and blood vessels
66
The characteristic histological finding of Pagets is a (blank) pattern, making bone look like a jigsaw
mosaic pattern
67
T/F: even though the bone is denser it is weaker in Pagets
true
68
what virus can cause Pagets?
paramyxovirus causing MEASLES
69
explain how a virus can induce Pagets?
virus induces IL6 which activates osteoclasts and blasts are then in reponse to the clasts
70
90% of Pagets are (poly/.mono) ostic
polyostotic including pelvis, spine, and skull
71
THe axial skeleton and proximal femur are involved in what percent of pagets?
80%
72
What bones are rarely affected by Pagets?
ribs, fibula, small bones of hands and feet
73
t/F: most cases of Pagets are asymptomatic and found only by chance
true
74
What are the early symtpoms of Pagets?
headache, hearing loss, visual changes, pain is the most common problem
75
What is the cause of pain and HA in Pagets?
microfractures and bone overgrowth which compresses spinal and cranial nerve roots
76
What is the name for the Paget facies?
leonine facies; difficult to stand upright due to wt. of the bone
77
Severe secondary osteoarthritis arises in Pagets due to what>
severe bowing of the long bones from the weight
78
The increase in blood flow in severe polyostotic Pagets causes a (blank), resulting in high output cardiac failure
functional arterio-venous shunt
79
What is the characteristic finding of Pagets on XRAY?
cotton wool spots
80
Giant cell tumors, sarcomas, and extramedullary hematopoiesis are complications of what dz?
Pagets
81
T/F: giant cell tumors are benign
true
82
WHat are the lab values that are abn in pagets?
inc. serum Alk phos
inc. urinary hydroxyproline
NORMAL serum calcium and phosphate
83
WHat is the Tx for Pagets?
anti-resorptive agents like biphosphonates and calcitoniin
84
T/F: osteopetrosis makes brittle bones
true
85
Osteopetrosis is too much (mineral/osteoid)
mineral
86
What can cause osteosclerosis?
osteopetrosis
87
A variant of osteopetrosis is caused by a def. in what enzyme necessary for excretoin of Hydrogen ions to acidify the environment to resorb matrix?
carbonic anhydrase II
88
```
What are the labs for osteomalacia/rickets?
Calcium
Phosphate
ALK PHOS
PTH
```
Calcium dec.
Phosphate dec.
ALK PHOS inc.
PTH inc.
89
```
What are the labs for osteopetrosis?
Calcium
Phosphate
ALK PHOS
PTH
```
Calcium normal
Phosphate normal
ALK PHOS inc.
PTH normal
90
```
What are the labs for osteoporosis?
Calcium
Phosphate
ALK PHOS
PTH
```
Calcium normal
Phosphate normal
ALK PHOS normal
PTH normal
91
```
What are the labs for Pagets?
Calcium
Phosphate
ALK PHOS
PTH
```
Calcium normal
Phosphate normal
ALK PHOS variable
PTH normal
92
What disease presents with brown tumors in the bone?
osteitis fibrosa cystica
93
vitamin d def leads to an increase in what substance in the bone?
osteoid
94
what is the vitamin d precursor from plants?>
ergosterol
95
what is vitamin d bound to on its way to the liver?
a-1-globulin d binding protein
96
In the (blank) vitamin d is converted to 25-OH vit d and in the (blank) it is then converted to 1,25OH-D, which is the active form
liver then kidney
97
elevated 1,25 OHD inhibits (blank)
alpha hydroxylase
98
hypocalcemia stimulates what hormone?
PTH, which activates alpha hydroxylase
99
Hypophosphatemia directly activates (blank) to increase 1,25 OH D
alpha hydroxylase
100
Vit D required for normal mineralizatoin of epiphyseal cartilage and (blank) matrix
osteoid
101
Overall, vit. d. def results in (blank) def
Calcium
102
What drugs break down vitamin D?
phenytoin, phenobarbitol, rifampin, CYP450
103
What is the mechanism of deformation in rickets?
overgrowth of epiphyseal cartilage
104
In rickets, there is an enlargement and lateral expansion of the (blank) junction
osetochondral junction
105
Why do you get a growth of capillaries and fibroblasts in the disorganized zones of rickets?
microfractures bring them in
106
an excess of osteoid in rickets produces (blank) and a squared appearance to the head
frontal bossing
107
Rachitic rosary is overgrowth of cartilage at the costochondral junction where?
in the chest
108
Pidgeon breast in rickets is due to what?
respiratory muscles pulling on the weak metaphyseal areas of the ribs
109
What is Harrison's groove?
girdling of thoracic cavity at lower margin of rib cage due to pull of diaphragm
110
lumbar lordosis and bowing of the legs is seen in ....
rickets
111
Are the contours of the bone affected in osteomalacia?
no
112
osteomalacia has an excess of what?
osteoid; too much and too weak
113
Which bones are most affected by osteomalacia?
vertebra and femoral neck
114
increased PTH levels leads to increased osteo(clast/blast) activity
clast
115
does hyperPTH affect cancellous or cortical bone more?
cancellous
116
Subperiosteal resorption produces thinned cortices and loss of (blank) around teeth (loosen)
lamina dura
117
The collection of changes seen in hyperPTH--brown tumor and cysts, make it also known as...
osteitis fibroas cystica
118
Renal Osteodystrophy Describes all the skeletal changes due to chronic renal disease including:
Increased osteoclastic bone resorption which mimics osteitis fibrosa cystica
Delayed matrix mineralization (osteomalacia)
Osteosclerosis
Growth retardation
Osteoporosis
119
renal failure results in retention of what ion?
phosphate
120
hyperphosphatemia also causes (hyper/hypo)calcemia, which leads to secondary hyperPTH
hypocalcemia
121
low levels of Vit. D, Ca, and renal failure contribute to what bone disease?
osteomalacia
122
Renal failure and low levels of vit. D make bone less responsive to (blank)
PTH
123
if a bone fracture breaks through the skin, what is likely to infect it?
S. aureus
124
What is a comminuted fracture?
splintered bone
125
All cases of avascular necrosis is caused by:
ischemia
126
What is the most common cause of AVN?
idiopathic with prior steroid use
127
What other dz's are implicated in AVN?
connective tissue diseases, sickle cell disease, radiation, alcohol abuse (mechanism unclear), tumors, trauma (ie joint displacement), etc.
128
What type of AVN results in triangular or wedge shaped infarcts?
subchondral infarcts
129
T/F: overlying cartilage in subchondral infarcts will die
false; will survive via nutrients from the synovial fluid
130
What type of AVN infarcts are geographic
medullary infarcts
131
is the cortex involved in medullary infarcts?
nope; collateral blood flow
132
what type of AVN causes chronic pain?
subchondral infarcts
133
subchondral infarcts may cause the cartilage to collapse and predispose to severe (blank)
osteoarthritis
134
Medullary infarcts are clinically (blank) except for large ones
silent
135
WHat are some causes of medullary infarcts?
Gaucher’s disease (fatty substances - sphingolipids accumulate)
Dysbarism (pressure changes)
Hemoglobinopathies
136
Which type of infarct remains stable over time?
medullary
137
how do the majority of osteomyelitis cases develop?
hematogenous spread
138
besides hematogenous spread, what are the ways that osteomyelitis can begin?
direct extension from a focus of acute infection in soft tissue or trauamatic implannation after compound fracture
139
what is the most common causative organism of osteomyelitis?
s. aureus
140
What are the common osteomyelitic agents in newborns?
E. coli, GBS,
141
Slamonella osteomyelitis is common in pts with...
sickle cell
142
mixed bacterial osteomyelitis common after....
trauma
143
T/F: half of the cultures of osteomyelitis are neg
TRUE
144
Bone abscesses, periosteal life, and extension into the joint are complications of osteomyelitis seen in what age group?
children
145
What is the most common location of a bone infection in children?
metaphysis
146
What is the most common location of a bone infection in adults?
anywhere in the bone
147
The residual necrotic bone, aka (blank) may be resorbed by the osteoclasts
sequestrum
148
large sequestra that cannot be resorbed are surrounded by a rim of reactive new bone called....
involucrum
149
(blank) are well-defined rim of sclerotic bone surrounding a residual abscess
Brodie's Abcess
150
changes on xray for bone infx may not appear for how long?
more than a week; already lots of damage has been done
151
What type of scan is helpful in localzing a bone infection?
gallium type radionuclide scanning
152
What is the Tx for bone infections?
hardcore abx and maybe debridement
153
what a severe complication of a distant organ of bone infx?
endocarditis
154
Systemic (blank) can also follow a bone infection
systemic amyloidosis
155
What kind of cancer can form along the sinus tracts of bone infections?
squamous cell
156
TB osteomyelitis favors what bones?
long bones and vertebra
157
TB osteom. lesions are (blank) in AIDS pts
multicentric
158
iWhere does the tB osteom. infx begin?
in the synovium, the bacteria needs oxygen
159
TB osteom. lesions may form cold abcesses of the (blank) muscle
psoas; aka Pott's disease
160
WHat are the four types of bone-forming tumors?
1. osteomas
2. osteoid osteoma
3. osteoblastoma
4. osteogenic sarcoma
161
what are the three types of cartilaginous tumors?
1. osteochondroma
2. endochondroma
3. chondrosarcoma
162
T/F: bone mets are more common than primary tumors
true
163
What is the most common malignant tumor of bone?
osteogenic sarcoma
164
When are benign tumors of bone most common?
last 3 decades of life
165
What age group gets malignant bone tumors?
the old
166
bone tumors are deposed as (blank) trabeculae and may or may not be mineralized
woven trabeculae
167
Osteomas are (blank), round to oval, and project from the subperiosteal or endosteal surfaces of the cortex
bosselated
168
Are osteomas benign or malignant?
benign
169
Do osteomas undergo malignant transformation?
nope
170
multiple osteomas of the skull may be assc'd with what disease?
Gardner's Syndrome aka familial polyposis
171
What is the difference between osteoid osteoma and osteoblastoma?
differ in size and location
172
What is the size difference betrween osteoid osteoma and osteoblastoma?
Osteoid osteomas by definition < 2cm in size
| Osteoblastomas > 2 cm
173
Both osteoid osteoma and osteoblastoma begin as a small, round, radiolucent (blank)
nidus; becomes sclerotic or mineralized; a rim of sclerotic bone is present at the edges
174
T/F: both osteoid osteoma and osteoblastoma are well circumscribed
true
175
If you don't completely excise osteoid osteoma and osteoblastoma, they will (blank)
recur
176
What bones does osteoid osteoma attack?
peripheral skeleton
177
What bones does osteoblastoma attack?
spine
178
Is osteoid osteoma or osteoblastoma painful at night?
osteoid osteoma from the production of excess PGE2
179
What characteristically relieves the pain assc'd with osteoid osteoma?
aspirin, inhibits PGE2 synth
180
Is pain relieved by aspirin in osteoblastoma?
nope
181
Osteogenic sarcoma arises from malignant cells of what embryo origin?
mesenchymal
182
What is the age for osteogenic sarcoma?
<20
183
Where in the bone does most osteogenic sarcoma arise?
metaphysis, 60% in the knee
184
mutations with which gene are associated with osteogenic sarcoma?
p53
185
The following microscopic findings are associated with which bone tumor?
Islands of primitive bony trabeculae
Rim of malignant osteoblasts
+/- Other mesenchymal elements (ie. cartilage)
osteosarcoma
186
what are the most common benign tumors of the bone?
osteochondroma aka osteocartilaginous exostoses
187
what type of tumor has a cauliflower appearance of mature bone with a cartilaginous cap?
osteochondroma
188
Where does osteochondroma arise?
metaphysis
189
T/F: osteochondroma presents with joint pain
false; asymptomatic, but does cause cosmetic deformities
190
are enchondromas benign or malignant?
benign
191
What are the common sites of enchondromas?
short tubular bones of hands and feet
192
Are enchondromas painful?
some, but usually asymptomatic
193
what are the two diseases associated with enchondromas?
Ollier's disease
| Maffucci's syndrome
194
Ollier's disease is weird becase it is enchondromas in what pattern?
down one side of the body
195
Maffucci's syndrome are multiple enchondromas associated with (blank) of soft tissue
hemagiomas
196
How frequent are chondrosarcomas?
1/3 with tumors
197
What is the second most common matrix forming tumor of bone?
chondrosarcoma
198
Where does chondrosarcoma start?
medullary cavity
199
Describe the appearance of chondrosarcoma in the medullary cavity?
expansile, glistening mass that spreads to the surface
200
Where does chondrosarcoma like to localize?
pelvis, shoulder, and ribs
201
Clear cell variants of chondrosarcoma are seen in the (blanks) of long tubular bones
epiphysis
202
Hematogenous mets of chrondrosarcoma go to the...
lung
203
What is a reactive, osteoclast like multinucleated mononuclear benign neoplasm?
giant cell tumor of bone
204
What has a soap bubble appearance on radiology?
giant cell tumor
205
what is the second most common childhood malignancy of bone?
Ewing's sarcoma
206
What is the first most common childhood malignancy of bone?
osteosarcoma
207
What is the 3rd most common bone tumor overall?
Ewing's sarcoma
208
What is the genetic basis for Ewing's sarcoma?
t(11,22); same as PNETs
209
Ewing's sarcoma forms Sheets of small cells with uniform nuclei, containing glycogen, aka ....
small blue cell tumor
210
Ewing's sarcoma is often misdiagnosed as (blank) because of extensive necrosis
osteomyelitis
211
What is the prognosis for Ewing's sarcoma?
young children are less likely to survive
212
EWing's sarcoma is an expanding (intramedullary/cortical) mass
intramedullary
213
Multiple myeloma is characterized by pockets of what type of cell?
plasma cells
214
Do all Ig's increase in MM?
nope
215
In (blank), Normal trabecular bone is replaced by proliferating fibrous tissue and disorderly islands of deformed bone
fibrous dysplasia
216
What is the most common form of fibrous dysplasia?
mono-ostotic; Starts during adolescence, then quiescent when bone growth stops
Ribs, calvarium, femur, tibia, jaw are common sites
217
Where do you see polyostotic fibrous dysplasia?
craniofacial with deformation; see it more in adults
218
Explain the interesting physical findings of the polyostotic form of fibrous dysplasia with endocrine abnls?
```
unilateral bone lesions
cafe au lait spots on same side
precocious puberty
hyperthyroidism
Cushing's disease
```
219
osteoarthritis is the degenration of...
articular cartilage
220
T/F: primary osteoarthritis arises without predisposing factors
true
221
what are the most important factors in the dev of osteoarthritis?
aging and wear and tear
222
what joints tend to get osteoarthritis?
wt. bearing
223
Cartilage in osteoarthritis has increased water and decreased (blank) content
proteoglycans
224
What type of collagen network is weakened in osteoarthritis?
type II
225
Chondrocytes relase which cytokine that causes the release of proteolytic enzymes?
IL1
226
The articular surface undergoes splitting in (RA/OA)
OA
227
What the fuck is eburnation?
subchondral bone becomes thickened, and gives appearance of ivory
228
(blanks) may form within bone as cracks in cartilage allow synovial fluid into bone in OA
cysts
229
Heberden's nodes of osteophytes may appear on what joints in OA?
DIP
230
While Heberden's node is on the DIP, Bouchard's node is on the (blank)
PIP
231
Is RA symmetric or asymmetric?
symmetric, starts in the small joints of the hands, feet
232
Does RA improve with heat or cold?
heat
233
Does RA present with heat, redness and swelling?
yes
234
What is up with the mucin level in the joint tap in RA?
low levels
235
What would you see on an XRAY of a joint with RA?
erosions
236
RA presents with nonsuppurative chronic proliferative (synovitis/tenosynovitis)
synovitis
237
the pannus and mantle configuration of RA is proliferation and hypertrophy of what cells?
synovial lining cells
238
T/F: lymphoid follicles may develop in the RA joint
true
239
The pannus is characterized by what gross appearance of the synovium?
formation of villi!!
240
Where do you get subQ nodules in rA?
along the forearm and areas of pressure
241
Describe the microscopic findings of the RA nodules?
Central focus of fibrinoid necrosis
Surrounded by palisading macrophages
Rimmed by granulation tissue
242
what bug causes lyme disease?
Borrelia burgdorferi
243
What is the rodent that carries lyme disease?
deer tick Ixodes dammini
244
what is the major arthropod borne disease in the US?
lyme disease
245
lyme disease tends to attack which joints first?
large joints like the knee, shoulder, and elbow and MIGRATES
246
lyme disease in early stages resembles what?
RA
247
what chronic inflamm. disease affects the sacroiliac joints?
akylosying spondylitis
248
Describe the look of gout crystals?
needle shaped and birefringent
249
gouty tophi are seen in what reaction?
chronic granulomatous reaction
250
What are some of the complications of gout crystals?
joint deformity and renal tubular injury or formation of stones
251
Is gout caused by uric acid over production or under excretion?
over production
252
What is the rare enzyme defect that can cause gout>
HGPRT
253
What would cause a rapid increase in urate production that would cause secondary gout?
rapid cell lysis during tx for lymphoma or leukemia
254
What would be a disease that would cuase decreased excretion of urate?
chronic renal insufficiency
255
What is Lesch-Nyhan Syndrome?
over production and over exprection of uric acid with NO HGPRT AT ALL
256
Urate crystals in the synovium are chemotactic and can activate (blank)
complement and generate C3a and C5a
257
Describe the order of involvment of gouty joints?
hallux, instep, ankle, heel, and then wrist
258
Where do you normally find pseudogout?
in the knee after surgery
259
What are the shape of the calcium pyrophosphate cyrstals?
coffin shaped
260
T/F: pseudogout can cause an acute attack of arthritis that lasts one day to four weeks
true
261
what are slow twitch fibers
type 1
262
what are fast twitch fibers
type 2
263
are cross striations retained in muscle atrophy?
yes
264
a grouped nature of muscle atrophy suggests what about its origin?
neurogenic
265
what is the most common type of muscle atrophy and what causes it?
type 2 fast twitch atrophy
Disuse (bedridden)
Glucocorticoid use - Longterm
Hypercortisol state for any reason
266
type 2 atrophy is difficult to distinguish from (blank) atrophy histologically
neurogenic
267
myesthenia gravis is an acquired disorder that affects transmission at what part of the synapse?
junction
268
T/F: in myesthenia gravis, Ab titer relates to the severity of the symptoms
false!!!
269
T/F: MG is associated with other autoimmune disorders
yes, as is the case with most autoimmunes
270
What are the two pathologies associated with MG?
thymus hyperplasia
| thymomas
271
What seems to be the source of the AchR Abs in MG?
the thymus
272
What happens with the eyes in MG?
Ptosis and diplopia in the evening
273
T/F: severe MG can affect the respiratory muscles
true
274
What is the Tx for MG?
Anti-ACh agent(Edrophonium chloride, akaTensilon) for transient fix
Cholinesterase inhibitors (e.g. Mestinon® or Progstimin®) administered. Success and dosages vary widely.
Most patients show improvement after thymectomy
275
DMD has what mode of inheritance?
X-linked
276
(proximal/distal) muscles are affected in DMD?
proximal
277
what muscles get really big in DMD?
calf muscles
278
What are you missing in DMD that causes the muscle shearing?
dystrophin
279
What are the histologic characteristics of DMD?
marked variation in muscle fiber size, with
| hypertrophy and atrophy of adjacent fibers
280
BMD is an (abscence/mutation) in dystrophin
only a mutation; less severe than DMD
281
Rhabdomyoma is a cardiac form of skeletal neoplasm assocated with (blank)
tuberous sclerosis
282
(blank) is probably a hamartoma
Rhabdomyoma
283
What is the most common soft tissue sarcoma in children?
Rhabdomyosarcoma
284
What is the embryonal variant of rhabdomyosarcoma in the GU tract?
Sarcoma botryoides; gelatinous GRAPE LIKE structures
285
embroyonal rhabdomyosarcoma has scattered skeletal muscle strap cells and appears as....
primitive small round blue cells
286
What are the three variants of rhabdomyosarcoma?
1. embryonal
2. alveolar
3. pleomorphic
