Bone/Soft tissue Pathology Flashcards
scurvy results from
vitamin C deficiency
impaired collagen formation leads to
poor vessel support, bleeding tendency
inadequate synthesis of osteoid
impaired wound healing
measure of bone turnover (serum marker)
osteocalcin
osteoprotegrin does what
blocks RANK
how long does bone mineralization take
12-15 days
lamellar bone
mature, orderly arrangement of collagen and osteoid
woven bone
immature, disorderly
cortical bone
on the outside
medullary bone
on the inside, softer
compact bone
mostly found in the cortical bone. Or flat bones
circumferential lamellae with haversian. No spaces
cancellous (trabecular) bone
is in the medullary locations.
medullary bone
hematopoeisis
w/ lamellae in between (spicules)
diseases impacting synovium
CVD, Lupus, RA, Lymes disease
dysplasias
abnormalities of bone and cartilage organogenesis
Achondroplasia
Osteogenesis Imperfecta
Osteopetrosis
dysostoses
congenital absence of bone, inappropriately fused bone, supernumerary bone
Activating mutation of FGFR3 receptor of the growth plate:
inhibits cartilage proliferation and decreased endochondral ossification.
achondroplasia
with rhizomelic shortening of the arms and legs
achondroplasia
midface hypoplasia results in
causes dental crowding, obstructive apnea, and otitis media
why do 3-7% of achondroplasia patients die within first year of life
because of brainstem compression (central apnea) or obstructive apnea
comorbidities with achondroplasia
- restrictive pulmonary disease with infection and cor pulmonale
- spinal stenosis
- ear infections
sudden death in achondroplasia caused by
brainstem compression
Lack of normal maturation and columnation and the presence of a bony end-plate in the metaphysis
achondroplasia
Abnormality in collagen type genes.
osteogenesis imperfecta
Within all OI, the fundamental abnormality is
too little bone
OI type I
Hearing loss (ossicles), Dental imperfections (abnormal dentin).
type II OI
usually lethal in utero or within days after birth. Excessive bone fragility with multiple bone fractures while the fetus is in the uterus. Blue sclerae.
type III OI
Severe clinical form in children surviving the perinatal period. Multiple fractures, progressive deformities. The sclerae are normal.
type IV OI
Compatible with survival. Short stature, moderate skeletal fragility.
which types of OI are most compatible with life
I, IV
Blue sclerae, dental abnormalities
OI
Brown, short teeth result from
failure in the formation of dentin(dentinogenesis imperfecta)
osteoclast deficiency/abnormality resulting in
osteosclerosis
There is failure to resorb calcified cartilage in the growth plate.
osteopetrosis
vitamin D deficiency
rickets/osteomalacia
excess of unmineralized bone matrix
rickets/osteomalacia
Overgrowth of growthplate at costochondral junction
rickets
Rachitic rosary due to
pull on costochondral cartilage –also due to the pull of the respirtaory muscles with bending of the ribs inward resulting in pidgeon breast deformity
osteomalacia findings
Prominent unmineralized osteoid in bone, weak bone, vulnerable to fractures (mostly vertebrae and femoral neck).
are there similar skeletal deformities in osteomalacia?
no. bone is already formed
differentiating osteomalacia from osteopetrosis
osteomalacia: decreased mineralized bone, same hyper cartilage
lucent lines (pseudo fractures)
osteomalacia
When mechanical stress is placed upon bone, osteoprogenitor cells produce WNT proteins that bind to receptors on osteoblasts, increasing β-catenin. As a result, what protein is most likely to diminish osteoclast activity and increase bone formation?
osteoprotegerin
can bind RANK ligand to reduce its binding to RANK and reduce the nuclear factor kappa B transcription factor and diminish osteoclast activity.
cranial nerve involvement
osteopetrosis
multiple osteomas associated with
Gardner’s syndrome
metastatic bone lesions favor
sites
axial skeleton, proximal long bones
prostatic mets are (lytic or blastic)
blastic- denser
thyroid mets are (lytic or blastic)
lytic- much looser
gardner’s syndrome findings
osteomas, epidermal cysts, fibromatoses and
colonic adenomatous polyposis
sharp, nocturnal pain relieved by aspirin
osteoid osteoma
duller pain not relieved by aspirin
osteoblastoma
which is larger- osteoid osteoma or osteoblastoma
osteoblastoma > 2 cm
enchondromatosis
more likely to undergo malignant transformation
maffuccis’s
chondromas associated with angiomas
malignancies associated with maffucci’s
ovary and brain malignancies
genetic syndromes associated with soft tissue tumors
NF1, FAP
HHV-8 associated with
Kaposi’s sarcoma
Gardner’s syndrome
Fibromatosis of the mesentery
Adenomas and Colon cancer
Osteomas of bone
Mutation in APC gene on chromosome 5
polyostotic FD+ endocrinopathy (precocious puberty) and skin pigmentation
Albright- McCune syndrome
