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Front 1

Which anatomical structure is abnormal in achondroplasia?

Back 1

growth plate

Front 2

What is the mode of inheritance and the pathogenesis in achondroplasia?

Back 2

autosomal dominant; Point mutation in gene that encodes FGFR3 leading to inhibition of cartilage formation

Front 3

Describe the histological features of achondroplasia at the level of the growth plate?

Back 3

disorganized and narrowed zone of proliferation in growth plate with clusters of chondrocytes instead of columns; premature ; bone formation seals the plate; intramembranous bone formation is normal

Front 4

What is the life expectancy and intelligence in achondroplasia:?

Back 4

Normal

Front 5

Describe clinical and pathogenetic difference between achondroplasia and thanatophoric dwarfism?

Back 5

Thanatophric dwarfism: mutation of FGFR3 that is different from achondroplasia; lethal with death from respiratory insufficiency; limb shortening and small chest

Front 6

Why is the bone brittle in osteogenesis imperfecta?

Back 6

Deficiencies in synthesis of type 1 collagen leads to cortical thinning, attenuated trabeculae, and hypercellular woven bone

Front 7

What is the clinical difference between type 1 and 2 OI?

Back 7

Type II is lethal in utero with multiple intrauterine fractures; Type I has a normal life span, increased number of fractures, blue sclerae, hearing loss, misshapen teeth; often acquired. Less normal collagen synthesized result in mild skeletal abnormalities. More severe or lethal forms result from abnormal polypeptide chains that cannot form the triple helix of collagen

Front 8

Describe the pathological features of OI?

Back 8

Cortical thinning, attenuated trabeculae, hypercellular woven bone – too little bone

Front 9

Why is osteoporosis a major health care problem?

Back 9

Complications of fracture of femoral neck, pelvis, spine with pulmonary embolism or pneumonia secondary to fractures

Front 10

List the 3 main types of osteoporosis?

Back 10

Age-related bone loss (senile osteoporosis), post-menopausal osteoporosis, disuse osteoporosis

Front 11

What is the difference between low- and high-turnover variant of OP?

Back 11

Low turnover variant: osteoblasts from older individuals have reduced reproductive and biosynthetic potential – senile OP; High turnover variant: activation of osteoclasts – post-menopausal OP

Front 12

Describe the the gross and microscopic features of OP?

Back 12

Gross: bones lack medullary canal, and the ends of long bones are bulbous and misshapen Histology: thinned trabeculae, microfractures, vertebral collapse (post-menopausal); Cortex thinned, Haversian system widened (senile)

Front 13

How sensitive is a plain X-ray to detect OP?

Back 13

Plain x-rays only detect greater than 30% bone loss

Front 14

Are serum calcium and phosphate abnormal in OP?

Back 14

NO

Front 15

Define Paget disease and name 3 stages?

Back 15

Increased osteoclastic and osteoblastic activity with disordered and architecturally abnormal bone formation resulting in a gain in bone mass; Osteolytic → mixed osteoclastic-osteoblastic (predominant ostoblastic) → burn-out quiescent osteoclerotic stage

Front 16

How common is Paget disease?

Back 16

Very common (5 to 11% of adults are affected)

Front 17

Describe the histological features of Paget’s in term of stages?

Back 17

Increased osteoclastic activity with numberous absorption pit, then prominent osteoblasts lining bone surfaces. Adjacent marrow hypervascular. Woven bone formation followed by lamellar bone with mosaic pattern (“jigsaw puzzle”). Prominent cement line annealing haphazardly oriented units of lamellar bone

Front 18

How many bones and which bones are typically involved in Paget’s?

Back 18

Monostotic (15%), polyostotic (85%). Axial skeleton and proximal femur

Front 19

Is there a laboratory abnormality in Paget’s?

Back 19

Serum alkaline phosphatase increased

Front 20

Describe the clinical features of Paget’s and long term risk(s)?

Back 20

Pain (microfractures, compression of nerve roots). Deformities (bowing of femur). Increased blood flow may lead to high output cardiac failure (AV shunting) . Malignant transformation (high-grade bone sarcoma) in 5-10% of pts with severe polyostotic disease

Front 21

Define “pathological” and “stress” fracture?

Back 21

Pathological fracture: bone was already altered by disease process. Stress fracture: slowly developing incomplete fracture after increased physical activity

Front 22

Describe the histological changes over time in fracture healing?

Back 22

Soft callus (procallus): hematoma → influx of imflammatory cells → fibroblasts → new capillary vessels → activation of osteoprogenitor cells → osteoclastic and osteoblastic activity Bony callus:; Subperiosteal formation of woven bone. ; Trabecualae perpendicular to cortical axis. ; Chondroblasts may form cartilage with subsequent enchondral ossification. ; Then remodeling; bone may return to completely normal shape

Front 23

List factors that predispose to avascular necrosis (list 6)?

Back 23

mechanical vascular interruption (fracture).; corticosteroids.; thrombosis and embolism (sickle cell anemia).; vasculitis, radiation injury.; increased intraosseous pressure.; venous hypertension.

Front 24

Describe the gross and microscopic features of bone infarct (medullary vs. subcortical)?

Back 24

Medullary infarcts: cancellous bone and marrow (cortex not affected due to collateral blood flow). ; Subcortical infarct: wedge-shaped, overlying cartilage is viable. Dead bone: empty lacunae, necrotic adipocytes

Front 25

Define creeping substitution?

Back 25

fatty acids bind calcium with formation of insoluble calcium soaps; resorption of dead bone with new bone formation (“creeping substitution”)

Front 26

Describe the clinical symptoms and possible complications of bone infarct (list 2 complcations)?

Back 26

Subchondral infarct: chronic pain (collapse of dead bone leads to severe osteoarthritis). Medullary infarct: often silent Complications: osteoarthritis and malignant transformation to sarcoma

Front 27

Which are the routes of infection in pyogenic osteomyelitis?

Back 27

Hematogenous (most common). Extension from contiguous site. Direct implantation

Front 28

Which organisms are typically found in acute osteomyelitis and which is the most common?

Back 28

Staph. Aureus (most common); E. coli, Pseudomonas, Klebsiella, Group B strep (neonates), salmonella in sickle cell anemia

Front 29

Describe the histological features of osteomyelitis?

Back 29

Acute inflammation → bone necrosis → bacteria within shafts and along Haverisian system to reach periosteum (sub-periosteal abscesses)

Front 30

Define the following terms:?

Back 30

Sequestrum – dead piece of bone. Draining abscess – rupture of periosteum, thru soft tissue to the skin. Involucrum – sleeve of reactive bone around sequestrum. Brodie’s abscess – small intracortical abscess

Front 31

Describe the radiographic appearance of osteomyelitis?

Back 31

Lytic focus surrounded by sclerosis

Front 32

List 4 complications of osteomyelitis?

Back 32

Fracture, endocarditis, sepsis, squamous cell carcinoma (long-standing draining sinuses)

Front 33

Which sites are typically involved in tuberculous osteomyelitis?

Back 33

spine (“Pott disease”), knees, hips

Front 34

Define Pott’s disease?

Back 34

Tuberculous osteomyelitis involving the spine

Front 35

Define osteoarthritis?

Back 35

a degenerative joint disease that involves progressive erosion of articular cartilage

Front 36

List conditions that predispose to osteoarthritis?

Back 36

developmental deformity, diabetes, marked obesity, repeated trauma (athletes)

Front 37

Describe the histological features of osteoarthritis and progression of changes?

Back 37

Chondrocyte proliferation → formation of clones → fibrillatin and cracking of chondroid matrix → softening, then sloughing of cartilage → “eburnation” (subchondral bone appears like polished ivory) Sclerosis and remodeling of underlying bone; Small fractures lead to dislodgement of small pieces of bone and cartilage (loose bodies or joint mice); Subchondral cysts; Osteophytes (bony outgrowths) at margins of joints

Front 38

Which joints are most frequently involved in osteoarthritis?

Back 38

Hips, knees, lumbar and cervical spine, interphalangeal and 1st carpometacarpal and tarsometatarsal joints

Front 39

Describe the histological features of rheumatoid arthritis?

Back 39

Thick, hyperplastic synovium with villous fronds; Prominent lymphoplasmacytic infiltrate; “rice bodies” and pannus

Front 40

Pannus:?

Back 40

Fibrocellular mass of synovium and stroma containing inflammatory cells and fibroblasts, causing erosion of cartilage leading to fibrous and bony ankylosis

Front 41

How common are rheumatoid nodules in the setting of RA?

Back 41

25% of patients

Front 42

Describe the typical location and histological appearance of rheumatoid nodules?

Back 42

Areas subject to pressure (less commonly in viscera – lungs, myocardium) Central fibrinoid necrosis, rim of epithelioid palisaded histocytes and mononuclear cells

Front 43

Explain why gangrene of the fingers is a possible complication of RA?

Back 43

Vasculitis

Front 44

Describe the histological features of acute and chronic gout?

Back 44

Acute gout: dense neutrophilic infiltrate; urate crystals in neutrophils in synovium and fluid; Chronic gout: urate deposits encrust articular surfaces → hyperplastic synovium → pannus → bony erosions → ankylosis

Front 45

Describe the crystals in gout and how they are distinguished from the crystals in pseudogout?

Back 45

yellow and parallel, negatively birefringenent, needle-shaped in gout; Pseudogout: white friable deposits, weakly positively birefringent

Front 46

Define tophus?

Back 46

large aggregations of urate crystals surrounded by inflammatory cells and multinucleated foreign body giant cells

Front 47

How does the histology of osteoid osteoma differ from the histology of osteoblastoma?

Back 47

both histologically identical

Front 48

Describe the typical age, size, location and symptoms in osteoid osteoma?

Back 48

10-30 y/o (male), <2 cm, appendicular skeletal (cortex of femur and tibia), intense nigh pain relieved by aspirin

Front 49

Why is aspirin effective in relieving pain in osteoid osteoma?

Back 49

Inhibits prostaglandin synthesis

Front 50

Describe the difference between osteoid osteoma and osteoblastoma (size of lesion, patient age, location, symptoms)?

Back 50

Osteoblastoma: larger lesions; similar but wider age range; spine; dull pain unresponsive to aspirin

Front 51

Describe the histological features of osteoid osteoma and osteoblastoma?

Back 51

Randomly interconnecting trabeculae of woven (immature) bone; prominent osteoblastic rimming; increased vascularity (congested capillaries)

Front 52

Nidus:?

Back 52

Actual tumor in osteoid osteoma, surrounded by prominent bone sclerosis

Front 53

Is a nidus seen in osteoblastoma?

Back 53

YES

Front 54

Define osteosarcoma?

Back 54

a malignant mesenchymal tumor in which cancerous cells producing bone matrix (malignant bone formation); The formation of bone by the tumor cells is most characteristic of osteosarcoma

Front 55

Describe frequency and typical age for conventional type osteosarcoma?

Back 55

20% of primary non-hematopoietic bone malignancies; Bimodal: 75% younger than 20yrs, older patients secondary to pre-existing conditions (Paget disease, bone infarct/radiation)

Front 56

Which conditions predispose to osteosarcoma?

Back 56

Paget disease, bone infarct, bone radiation

Front 57

Describe the typical location of conventional type osteosarcoma?

Back 57

Metaphysic of long bones (around knee, hip, proximal humerus, craniofacial bones)

Front 58

Describe the histological features of high grade osteosarcoma (is the growth plate involved, is cartilaginous differentiation seen…?

Back 58

) ; Hemorrhagic, variably gritty; infiltrates the medullary canal (not growth plate); destroys overlying cortex and produce a soft tissue mass; Large hyperchromatic nuclei; bizarre tumor giant cells; mitoses; The noeplastic bone has a course, lacelike architecture; When malignant cartilage is abundant, the tumor is called chondroblastic osteosarcoma

Front 59

List metastatic sites of osteosarcoma?

Back 59

lungs, bones, brain

Front 60

Describe the typical X-ray appearance of conventional osteosarcoma?

Back 60

lytic/blastic, permeative margins, reactive periosteal bone formation, Codman triangle (raised periosteum/cortex)

Front 61

Define Codman’s triangle?

Back 61

triangular shadow b/w cortex and raised ends of periosteum

Front 62

What is the treatment for conventional type osteosarcoma?

Back 62

Chemotherapy and complete wide resection

Front 63

Define osteochondroma and explain its histogenesis?

Back 63

A benign cartilage-capped outgrowth that is attached to the underlying skeleton by a bony stalk

Front 64

Describe the shape, site and direction of growth of osteochondroma?

Back 64

Grows diagonal to long axis away from joint ; Arise from metaphysic near the growth plate of long tubular bones, esp. about the knee

Front 65

Describe the histological features of osteochondroma (what relationship exists between the medullary canal of the underlying bone and the lesion?

Back 65

).; Enchondral ossification of inner aspect of cartilage and bone similar to growth plate; Medullary cavity of underlying bone and osteochondroma are continuous.; Outer layer of head of osteochondroma: benign hyaline cartilage delineated peripherally by perichondrium; cartilage has the appearance of disorganized growth pate and undergoes endochondrial ossification with the underlying bone

Front 66

Define enchondroma?

Back 66

benign bumors of hyaline cartilage arising within medullary cavity (enchondroma) or on the surface (sub)periosteal

Front 67

What is the typical patient’s age and site involved in enchondroma?

Back 67

20-50 y/o; metaphysic of tubular bones (hands and feet)

Front 68

Define Ollier’s disease and Mafucci’s disease?

Back 68

Ollier disease: multiple enchondromatosis.; Mafucci disease: multiple enchondromatosis + soft tissue hemangiomas

Front 69

Describe the typical gross, radiographic, and histologic features of enchondroma?

Back 69

Gross: gray/blue translucent (like hyaline cartilage); Micro: well-circumscribed nodules with a hyaline matrix surrounded by metaplastic bone. Slow growth with endosteal scalloping but no cortical destruction

Front 70

“O-ring sign:”?

Back 70

Thin rim of radio-dense bone around lobules of cartilage present in x-rays of osteochondroma

Front 71

How common is malignant transformation in enchondroma?

Back 71

more common than solitary chondromas. Maffucci syndrome is at risk for developing other types of malignancies

Front 72

What is the typical age and site of involvement in chondroblastoma (note that the lesion is usually in the epiphysis)?

Front 73

In addition to chondroblastoma, name another 2 benign cartilage tumors and the respective typical patient’s age?

Back 73

No answer

Front 74

Describe the typical age, gender and site of involvement for chondrosarcoma?

Back 74

> 40 y/o (male); Central skeleton (pelvis, shoulder, ribs) and proximal extremities

Front 75

Describe the radiographic features of chondrosarcoma. Note that stippled calcifications (irregular opacities) can be seen in benign and low grade malignant cartilage tumors?

Back 75

prominent endosteal scalloping, cortical destruction, soft tissue extensions

Front 76

Describe gross and histological features of chondrosarcoma in relation to tumor grade?

Back 76

Gross: large bulky tumors are nodules of gray-white translucent, glistening tissue. Grade 1: hyaline matrix, mild atypia; Grade 2: more myxoid matrix, increased cellularity, mitoses. Viscous and gelatinous and ooze from the cut surface; Grade 3: little matrix, increased pleomorphism

Front 77

What is the prognosis for chondrosarcoma in relation to histological grade?

Back 77

Grades 1 and 2 are usually indolent with a good prognosis; Grade 3 tend to disseminate; Think "C" is 3rd letter, so 3 grades.

Hint 77

None

Front 78

What therapy is effective for chondrosarcoma?

Back 78

Complete surgical exscision (chemo/radiotherapy not effective)

Front 79

Define dedifferentiated chondrosarcoma and its frequency?

Back 79

Transformation to high-grade sarcoma lacking chondroid differentiation – 10%

Front 80

Define fibrous cortical defect, its frequency and most likely pathogenesis?

Back 80

Very common (30-50%) of children.; Most likely developmental defect.; Eccentric metaphyseal lesion.

Front 81

Describe the typical location and radiographic appearance of fibrous cortical defect?

Back 81

Distal femur and proximal tibia; Eccentric lobulated raiolucency surrounded by a thin zone of sclerosis

Front 82

What is the difference between fibrous cortical defect and non-ossifying fibroma?

Back 82

Non-ossifying fibroma is a large fibrous cortical defect extending into the medullary canal

Front 83

Describe the histological features of fibrous cortical defect/non-ossifying fibroma?

Back 83

Spindled fibroblasts in a “storiform” (pin-wheel) pattern, admixture of osteoclast-like giant cells and foamy histiocytes

Front 84

What is the clinical evolution of fibrous cortical defect?

Back 84

Spontaneously resolve, unless complicated by fracture

Front 85

Define fibrous dysplasia?

Back 85

Tumor-like lesion characterized by localized developmental arrest of bone formation

Front 86

Describe the typical patient’s age, site, X-ray appearance, clinical evolution of fibrous dysplasia?

Back 86

Monostotic variant: Early adolescence; variable sites; asymptomatic. ; Polystotic variant: earlier age than monostotic; multiple bones with frequent craniofacial involvement; deformities common (“shepherd crook), fractures; rare malignant transformation

Front 87

Describe the histological features of fibrous dysplasia?

Back 87

Curvilinear trabeculae of woven bone surrounded by fibroblastic proliferation without osteoblastic rimming of trabeculae. ; Shapes of trabeculae resemble “Chinese leters” or “alphabet soup”.

Front 88

How common is the monostotic vs. polyostotic variant of FD respectively?

Back 88

Monostotic (70%), polyostotic (27%)

Front 89

Define McCune Albright syndrome?

Back 89

Polyostotic fibrous dysplasia with endocrine abnormalties (precocious puberty, etc)

Front 90

Define Ewing’s sarcoma?

Back 90

A primary malignant small round cell tumor of bone

Front 91

What is the difference between Ewing’s sarcoma and PNET and does this distinction have clinical relevance?

Back 91

The most undifferentiated tumors – Ewing’s; those with evidence of neural differentiation – PNET

Front 92

What is the typical patient’s age and site involved in Ewing’s sarcoma?

Back 92

10-15 y/o (young age at presentation of all bone sarcomas); Diaphysis of long bones and pelvis

Front 93

Describe the radiographic features of Ewing’s sarcoma?

Back 93

Destructive permeative lesion, often extensive soft tissue component, periosteal reaction (“onion skin”)

Front 94

Describe the histological features of Ewing’s sarcoma (is this histological appearance specific for this tumor?

Back 94

) ; Sheets of uniform small round cells with scant cytoplasm; few mitoses. Evidence of neural differentiation in minority – Homer Wright rosettes

Front 95

How could you confirm the suspected pathology diagnosis of Ewing?

Back 95

Translocation t(11:22)

Hint 95

None

Front 96

What is the prognosis and treatment for Ewing’s sarcoma?

Back 96

Highly lethal without adjuvant therapy. With chemo/surgery (and maybe radiation) survival >50%

Front 97

Define giant cell tumor?

Back 97

Contains a profusion of multinucleated osteoclast type giant cells

Front 98

Describe the typical age and sites for GCT?

Back 98

Young to middle aged adults, after growth plate closure; Epiphyseal or epiphyseal/metaphyseal; around knee, but many sites may be involved

Front 99

What is the clinical behavior of GCT?

Back 99

Location of tumors in ends of bones near joints causes complaints of arthritic symptoms; pathologic fractures

Front 100

Describe the radiographic appearance of GCT (can you see soft tissue involvement?

Back 100

Lytic, often eccentric; may erode thru articular cartilage and cortex or extend into soft tissue

Front 101

Describe the histological features of GCT (what significance would you attribute to mitotic figures?

Back 101

Mononuclear cell component: proliferating component of the tumor, plump oval cells with frequent mitoses; Osteoclast-like giant cell component: numerous large giant cells interspersed with mononuclear cells

Front 102

Would the presence of lung metastases exclude a diagnosis of GCT?

Back 102

NO. ; There is a 4% chance of lung metastases in GCT

Front 103

What is more common: a primary or a metastatic bone tumor?

Back 103

How does this ratio relate to patient’s age?

Front 104

How do bone metastases reach the bone?

Back 104

direct extension; lymphatic or vascular dissemination; intraspinal seeding

Front 105

Which tumors metastasize to bone frequently?

Back 105

Adults: prostate, breast, kidney, lung; Children: neuroblastoma, Wilms tumor, osteosarcoma, Ewing’s rhabdomyosarcoma

Front 106

What are the most common sites for bone metastases?

Back 106

Axial skeleton, proximal femur, humerus

Front 107

Define blastic vs. lytic bone metastases and which type is more common?

Back 107

Lytic: metastatic cells secrete substances such as prostaglandins, ILs, and PTH-related proteins that stimulate osteoclastic bone resorption (tumor cells themselves do not directly resorb the bone); Blastic: elicit a sclerotic response by stimulating osteoblastic bone formation; Most metastases: mixed lytic/blastic

Front 108

Which tumors tend to form blastic metastases?

Back 108

Prostate and breast

Front 109

Describe the typical age, location and histology of lipoma?

Back 109

Most common soft tissue tumor ; Mid-adulthood; Resembles mature fat, but more variation in cell size

Front 110

Name 3 histological variants of lipoma?

Back 110

Angiolipoma, spindle cell lipoma, pleomorphic lipoma

Front 111

Define liposarcoma?

Back 111

Arise in deep soft tissues of proximal extremities and retroperitoneum

Front 112

How common is liposarcoma (relatively speaking)?

Back 112

Most common adult sarcoma;

Front 113

List the main histological subtypes of liposarcoma and their respective grade?

Back 113

Well-differentiated; Myxoid: intermediate grade; Round cell, pleomorphic: high grade; Dedifferentiated: high grade sarcoma arising in a well differentiated liposarcoma What is the histological hallmark of lliposarcoma?

Front 114

Define nodular fasciitis?

Back 114

Reactive pseudo-sarcomatous proliferation

Front 115

Why is nodular fasciitis referred to as a “pseudosarcomatous” proliferation (pay attention to both clinical and histological features)?

Back 115

It is clinically alarming because of rapid growth and histological appearance (increased cellularity and mitoses)

Front 116

Describe the typical age and site of involvement for nodular fasciitis?

Back 116

Adults. Subcutaneous or intramuscular nodule on forearm, chest, or back

Front 117

How common is a history of trauma in nodular fasciitis?

Back 117

History of trauma <15%

Front 118

Describe the histological features of nodular fasciitis?

Back 118

Richly cellular, plump immature fibroblasts; spindle to stellate cells, prominent nucleoli, high mitotic activity, admixed inflammatory cells and extravasated red blood cells

Front 119

Define myositis ossificans?

Back 119

Ossifying benign fibrous lesion, intramuscular or subcutaneous, with metaplastic bone

Front 120

How common is a history of trauma in myositis ossificans?

Back 120

>50%

Front 121

Describe the histological features and their evolution over time in myositis ossificans?

Back 121

Initially fibrous proliferation → then bone formation in the periphery → zonation

Front 122

Define zonation?

Back 122

Center soft with fibroblasts; immediate zone of osteoblastic deposition of trabeculae of woven bone; peripheral zone of mature bone; eventually, the entire lesion ossifies

Front 123

Define fibromatosis?

Back 123

Nodular or poorly defined fascicles of mature-appearing fibroblasts surrounded by abundant dense collagen

Front 124

List 3 types of superficial fibromatoses?

Back 124

Palmar (Dupuytren’s contracture), plantar, penile (Peyronie’s disease)

Front 125

Describe the histology of fibromatosis?

Back 125

Nodular proliferation of mature appearing fibroblasts

Front 126

Define desmoid fibromatosis?

Back 126

(deep-seated fibromatosis) lie in interface between exuberant fibrous proliferations and low-grade librosarcomas

Front 127

Why is desmoid fibromatosis often difficult to treat?

Back 127

Locally invasive with high recurrence rate when incompletely removed

Front 128

What is the risk of malignant transformation in desmoid fibromatosis?

Back 128

Does not metastasize

Front 129

List typical sites of involvement in desmoid fibromatosis?

Back 129

Extra-abdominal (trunk and proximal extremities); Abdominal (anterior abdominal wall following pregnancy); Intra-abdominal (mesentery or pelvis

Front 130

Define Gardner’s syndrome?

Back 130

Familial adenomatous polyposis and desmoids

Front 131

List one characteristic histological feature of fibrosarcoma?

Back 131

Herringbone pattern of intersecting fascicles ; Think FI_S...FISH

Hint 131

None

Front 132

Define fibrous histiocytoma vs. dermatofibroma?

Back 132

The dermal variant of fibrous histiocytoma is called dermatofibroma

Front 133

Describe the histological features of fibrous histiocytoma/dermatofibroma ;

Front 134

Define malignant fibrous histiocytoma?

Back 134

Aggressive adult sarcoma characterized by marked cytologic atypia (“very ugly tumor”)

Front 135

How common is MFH in comparison to other soft tissue sarcomas?

Back 135

Once considered the most common sarcoma of adults

Front 136

What is the cell of origin of MFH?

Back 136

Unknown, but clearly not histiocytic (maybe fibrous)

Front 137

Is the histological appearance of MFH specific for this diagnosis?

Back 137

No Describe gross and histological features of MFH?

Front 138

What is the clinical behavior of MFH?

Back 138

Most variants are aggressive with mestatses Define rhabdomyosarcoma?

Front 139

What is the histological hallmark of RMS?

Back 139

Rhabdomyoblast (eosinophilic cytoplasm, round or elongated shape (tadpole or strap cells)

Front 140

List 4 histological types, their respective patient’s age and site of involvement?

Back 140

Embryonal: <10 y/o; nasal cavity, orbit, prostate, parotid, testicular region; Sarcoma botryoides: <10 yr; polypoid grape-like protruding into hollow viscera (bladder, vagina, bile duct, nasopharynx); Alveolar: adolescents; deep muscles of extremities; Pleomorphic: adults

Front 141

Define sarcoma botryoides (what does that name mean and which anatomical sites are typically involved?

Back 141

); Grape-like appearance (botryoid); subtype of embryonal rhabdomyosarcoma

Front 142

Describe the main histological features of the main histological types of RMS?

Back 142

Embryonal: round and spindle cells with myxoid stroma; cambium layer seen in sarcoma botryoides (submucosal hypercellular zone of tumor cells). Alveolar: tumor cells more round and divided by delicate fibrous septa to tumor cells discohesive imparting a “pseudoalveolar” pattern (resemblance to lung alveoli). Pleomorphic: histology resembles malignant fibrous histiocytoma

Front 143

What is the prognosis for the respective types of RMS?

Back 143

Best fro embryonal (especially botryoid), poor for alveolar and pleomorphic

Front 144

Define leiomyosarcoma?

Back 144

Malignant tumor of smooth muscle

Front 145

How common is soft tissue leiomyosarcoma?

Back 145

10-20% of soft tissue sarcomas

Front 146

What are the typical sites of involvement for leiomyosarcoma?

Back 146

Skin or deep soft tissue of extremities and retroperitoneum

Front 147

Describe the histological features of leiomyosarcoma?

Back 147

Malignant spindle cells in interweaving fascicles with cigar-shaped nuclei; Histochemical and ultrastructural evidence of smooth muscle differentiation

Front 148

What is the prognosis of leiomyosarcoma?

Back 148

Depend on size, location, and histological grade

Front 149

Describe the histological difference between leiomyoma and leiomyosarcoma?

Back 149

Leiomyoma: spindle cells with blunt elongated nuclei; no pleomorphism or significant mitotic activity

Front 150

Define synovial sarcoma?

Back 150

Malignant tumor occurring near joints of extremities (mostly knees)

Front 151

What is the cell of origin of synovial sarcoma?

Back 151

Unknown, but not synovial cell origin

Front 152

What is the typical patient’s age and site of involvement in synovial sarcoma?

Front 153

Describe the histological types of synovial sarcoma and their relative frequency?

Back 153

Monophasic spindle cell variant (most common). ; Biphasic variant (areas of epithelial differentiation with gland-like structures surrounded by spindle cells). ; Pure epithelial variant (least common)

Front 154

List a single feature that sets synovial sarcoma apart from other sarcomas?

Back 154

Has epithelial features by morphology and immunohistochemistry

Front 155

How would you confirm the pathology diagnosis if in doubt?

Back 155

Translocation t(X:18)

Front 156

What is the prognosis and treatment for synovial sarcoma?

Back 156

Aggressive sarcoma treated with surgery/chemo or radiation. ;