2. PATH Pt 2: Bones Joints and Soft Tissue Flashcards
What is the MC benign bone tumor, aka exostosis, 85% are solitary in early adulthood, in AD* may see in younger+multiple lesions (20% progress to chondrosarcoma), more common in MEN (x3), assoc with EXT1/2 in sporadic osteochondromas, which encode heparin sulfate glycosaminoglycans, located at the METAPHYSIS near growth plate of tubular bone?
Osteochondroma (B9 cartilage forming tumor)
Osteochondroma of bone appears as a bony projection, most being solitary, incidental lesions that may be excised if they cause local pain, there is a rare condition of multiple Osteochondromas marked by bone deformity and by a greater propensity to develop?
chondrosarcoma
Osteochondroma has a bluish white cartilaginous cap which overlies the bony cortex, they are probably not true neoplasms but they are a lesion that extends outward from the metaphyseal* region, see disorganized growth, either sesile or pedunculated- continuous with?***
Medullary Cavity
What is a benign cartilage, solitary metaphyseal lesion usually on hands and feet in 20-50 y/o, may be within medullary cavity (completely inside=enchondroma) or on the surface aka subperiosteal or juxtacortical?
Chondroma
Ollier syndrome associated with multiple enchondroma, maffucci syndrome is associated with multiple enchondromas with angiomas leading to an increased risk of chondrosarcoma and other malignancies, what are two genes that are associated with Chondromas, same gene seen in GBM?
IDH1 and IDH2
Enchondroma are less than 3cm, gray blue and translucent, well circumbscribed nodules of hyaline cartilage (encased in thin layer of reactive bone) containing benign chondrocytes, the periphery may ossify, and the center can calcify and infarct, ollier and maffuci (hereditary) are associated with what additional presence within the enchondroma?
Increased cellularity and atypia
radiolucent nodule with central calcification DOES NOT penetrate cortex
What is the second MC malignant* matrix producing tumor of bone (osteosarcoma is first), more common in men (x2), usually in 40s+, lesions like axial skeleton (pelvis, shoulder, ribs), invade locally, painful enlarging mass may metastasize, 70% grade 3 which hematogenously spread to LUNGS, have a direct correlation between grade and behavior?
Chondrosarcoma
Chondrosarcomas grow fast and have nodules of hyaline and myxoid cartilage permeating throughout the medullary cavity, growing through the cortex and forming well circumscribed soft tissue masses, see anaplastic chondrocytes amid hylaine cartilage , *bizarre giant cells w multiple nuclei, have a calcified matrix appears as foci of *flocculent densities, what are those?
Resembling tufts of wool = flocculent
85% of Chondrosarcoma arise de novo or sporadically, the remainder occur in preexcisting osteochondromas or enchondromas, multiple osteochondroma syndrome assoc w mutations in EXT gene, chondromatosis-related and sporadic Chondrosarcomas are commonly associated with what gene?
IDH1/2 (+/-)
What syndrome presents at age 10-15, due to APC gene mutation, associated with multiple GI adenomas, thyroid and desmoid tumors, skin cysts and **Osteomas?
Gardner Syndrome
What is a benign lesions that is painful, usually worse at night and responds clinically to aspirin* and NSAIDs*, there is excess prostaglandin E2 production by osteoblasts, seen in young men - teens and 20s, located at appendicular skeleton = 50% FEMUR or TIBIA, lesions must be less than 2cm otherwise are considered osteoblastomas?
Osteoid Osteoma
severe nocturnal pain due to production of PGE2, releived via ASA
Osteoid Osteoma has a central nidus of translucent woven bone surrounded by a rim of osteoblasts, associated with a thick rind of reactive cortical bone = radiographic clue, they are with what?
Radiofrequency Ablation - easily
Osteoid Osteoma are composed of haphazardly interconnecting trabeculae of woven bone that are rimmed by prominent osteoblasts, what type of Osteoid Osteoma is in the cortex of the bone and has central mineralization surrounded by reactive bone?
Intracortical Osteoid Osteoma (nidus)
What is bigger than an osteoid osteoma (>2cm) involves the posterior spine*, has no bony reaction, achy pain that does NOT respond to aspiring, treated by curretted or excised in bloc, and malignant transformation is rare?
Osteoblastoma
What is the MC primary malignant tumor of the bone with malignant mesenchymal cells that produce bone matrix, presents as a painful enlarging mass, 75% are less than 20 males AROUND THE KNEE**, 2nd peak in older males with pagets or due to PRIOR RADIATION?
Osteosarcoma
Osteosarcoma is associated with Rb loss - 70% sporadic, TP53 is seens with Li-Fraumeni syndrome (breast cancer as well), INK4a gene, MDM2/CDK4 inhibit p53 and rb and are associated with large Osteosarcomas, on xray one sees mixed lytic and blastic mass with infiltrative margins, and what?***
Codman triangle- elevation of periosteum* due to proximal reactive bone
Chondrosarcoma in adults/Osteosarcoma in kids
Osteosarcoma is MC around the KNEE and due to prior radiation, spreads early to lung, surgery and chemo have a 70% 5yr survival, spreads hematogenously to lungs- 90% mets to lung, bones, brain who died with tumor, on histo see bizarre tumor giant cells*, malignant osteoid, abnormal mitosis, and is it known for extension where?
extends through the cortex outside of the bone - formation of bone by tumor cells is diagnostic
Where does osteosarcoma MC metastasize?
LUNGS
What tumors occur younger than 20 (80%), with predilection for WHITES, not blacks or asians, 2nd MC bone sarcoma in children, aka small blue round cell tumors w SCANT cytoplasm, undifferentiated with neural differentiation is known as primitive neuroectodermal tumor or PNET?
Ewing Sarcoma
Ewing Sarcoma is a painful enlarging mass with tenderness, warm and swelling, mimics infection because also has fever and increased ESR, a periosteal reaction occurs leading to reactive bone in onion-skin fashion on xray, MC in the diaphysis of LONG BONES especially?
FEMUR and flat bones
arises in medullary cavity and invades cortex
Ewing Sarcoma has a 75% 5 year survival with surgery, chemo, and radiation, the amount of chemo-induced necrosis (more is better) is an important PROGNOSTIC factor- indicates sensitivity to drugs, 85% show t(11;22)(q24:q12) which is a fusion of what two genes?
EWS-FL11 (EWS gene)
necrosis prior to therapy could indicate rapid growth = BAD
Sunburst pattern on xray and codman is associated with osteosarcoma, lamellated or onion-skin is associated with ewing, hair-on-end on xray is associated with spherocytosis, iron def anemia, neuroblastoma, hemolytic anemia, sickle cell disease, and thalassemia major…
meow
Ewing Sarcoma arises in the medullary cavity and invades the cortex, periosteum and soft tissue, sheets of small round blue cells with scant cytoplasm are seen, contain hemorrhage and necrosis, what type of rosettes are seen, which are round groupings of cells with central fibrillary core signaling a neuroextodermal differentiation or PNET?
Homer Wright Rosettes
What type of dysplasia is benign proliferation of fibrous tissue and bone that do not mature, may be a developmental anomaly, monostotic (70%) and usually asymptomatic- found incidentally but may cause pain/fracture/discrepancies in limb length, (polystotic is crippling), mostly occurs in early adolescence, M=F?
Fibrous Dysplasia
Fibrous Dysplasia shows a ground glass appearance, with well defined margins radiographically because it is benign. What is a type of fibrous dysplasia associated with GNAS1 mutation in embryogenesis, causing polyostotic disease associated with cafe-au-lait skin pigmentations and endocrine abnormalities- esp precocious puberty?
McCune-Albright Disease*
What syndrome is associated with fibrous dysplasia (usually polyostotic), along with multiple skeletal deformities in childhood such as soft tissue intramuscular myxomas?
Mazabraud Syndrome
Fibrous Dysplasia is composed of curvilinear trabeculae of woven bone that lack conspicuous osteoblastic rimming and arise in a background of fibrous tissue, commonly described as what characters?
Chinese characters
Somatic GNAS1 gain-of-function mutation, same gene is mutated in pituitary adenoma
• Constitutively active GS protein, activating cAMP→ cellular proliferation
• Extent of phenotype depends on stage in which the mutation occurs and the fate of cell harboring the mutation
• McCune Albright occurs when mutations happens during embryogenesis
• monostotic fibrous dysplasia happens when mutation occurs in one osteoblast precursor during or after skeletal formation
woof
What type of tumor of the bone has osteoclastoma multinucleated osteoclast-type GIANT cells, must consider brown tumor of hyperparathyroidism, occurs between 20-40s and is benign but locally aggressive, may be of monocyte-macrophage derivation, arises in epiphyses and may extend into metaphysis?
Giant cell tumor of bone
Giant cell tumor of bone is MC in knee- distal femur/proximal tibia causing arthritis like symptoms, tends to recur after curettafe, 4% mets to lungs and may regress and are seldomly fatal, histo shows predominantly lytic, expansile with destruction of the cortex, always see abundance of what?
Multinucleated giant cells
Metastatic tumors are the MC form of skeletal malignancy, spread via direct extension, lymph/hematogenous, or intraspinal seeding, in adults- 75% are from *prostate, breast, kidney and lung, in kids see mets from neuroblastoma, wilms, osteosarcoma, rhabdomyosarcoma and?
Ewing*
metastatic tumors are multifocal except kidney and thyroid are usually solitary, small bones of the hands usually mets from lung/kidney/colon, on XR you see lytic bone destroying lesions from kidney/lung/gi/MM, what facilitates implantation and growth - seen in the axial skeleton?
Red marrow (rich capillary and slow blood flow)
Metastatic tumors can be both mixed lytic and blastic, there is a dim prognosis, manage sx to limit futher spread but will probs die, what is the ONLY blastic or bone forming metastasis to bone?
Prostatic Adenocarcinoma**Unique
Joints allow movement while providing mechanical stability, they are classified as solid (nonsynovial) and cavitated. Solid joints aka synarthroses provide structural integrity and allow only minimal movement and they lack what?
Joint space (70% H20/10% Type II Collagen)
Synovial joints in contrast, have a joint space, that allows for a wide range of motion, situated between the ends of bones formed via enchondral ossification, they are strengthened by a dense fibrous capsule and reinforced by ligaments and?
muscles
Osteoarthritis is associated with thinned cartilage on the ends of the bones, allowing the bones to rub together causing creputis (later in life, progress over years, assymetrical to polyarthritis, weight bearing joints, stiff less than 1 hour* but END of day), while rheumatoid arthritis is do to what?
swollen inflamed synovial membrane
(happen at any age, rapid onset, symmetrical polyarthritis, usually small joints of hands and feet, stiff >1hour at BEGIN of day)
What is the MC type of joint disease, AKA degenerative joint dz DJD, primary or idiopathic due to aging, oligoarticular (few joints), increases exponentially >50 years, 40% of 70 year olds are affected, hands and knees in women and *hips in men?
osteoarthritis
*pain better with rest and NSAIDs