Module 6: Gout, Pseudogout, Bone Tumors Flashcards Preview

Pathology Post Midterm > Module 6: Gout, Pseudogout, Bone Tumors > Flashcards

Flashcards in Module 6: Gout, Pseudogout, Bone Tumors Deck (39):
1

First topic in this set is Gout, what is the etiology?

Idiopathic (aka unknown)

2

What are the pre-disposing factors for Gout?

Obesity
Red Wine
Red Meat
Alcohol
Lesch Nyhan (HGPRT deficiency)
Thiazides

3

Explain the connection between Gout and hyperuricemia?

High uric acid levels does not always lead to gout, but to get gout, you must have had high uric acid levels

4

What are the factors for gout in regards to secondary and primary gout?

Primary (90%): unknown enzyme defect + HGPRT deficiency
Secondary (10%): increased NA turnover (leukemia), chronic renal disease, inborn errors of metabolism

5

What is the pathogenesis for gout?

Macrophages engulf uric acid crystals -- complement activation --brings in neutrophils (Sign of acute inflammation)

6

What is acute gout?

Edematous soft tissue with acute inflammation (PMNs and Macrophages with phagocytized urate crystals) --- deposition of crystal in areas of low temp

7

What is chronic gout?

Form Tophi in articular cartilage of joints and soft tissue; foreign body type of granulomatous inflammation

8

What investigation is done for Gout?

Joint aspiration/atherocentesis
--yellow, negative birefringerence under plane polarized light

9

What are features of gout?

Monosodium Urate Crystals
Loves first metatarsal joint
Negatively birefringement
Needle shaped crystals
Yellow crystals

10

What is the etiology of pseudogout?

Hereditary: linked to chromosome 8 (ANKH gene, encodes transmembrane pyrophosphate transport channel)
Secondary: trauma, diabetes, amyloidosis, hyperparathyroidism, hemochromatosis
Idiopathic (sporadic)

11

What are features of pseudogout?

Calcium pyrophosphate crystals
Loves the knee
Positive birefringement
Rhomboid Crystals
Blue crystals

12

What is tumoral calcinosis?

Increased serum levels of calcium
--may be seen in children
--massive accumulations of hydroxyapatite crystals

13

The rest of the cards will be about bone tumors, what are the tumors of the diaphysis, metaphysis and epiphysis?

Diaphysis: Ewing's Sarcoma (malignant) and Adamantinoma (malignant tumor of fibro-osseous)
Metaphysis: Osteosarcoma (malignant tumor of bone), Chondrosarcoma (malignant tumor of cartilage), Osteochondroma (benign tumor of cartilage), Aneurysmal Bone cyst (Benign) and Enchondroma (benign tumor of cartilage)
Epiphysis: Chondroblastoma (benign tumor of cartilage) and Giant cell tumor (benign tumor)

14

What is the most common malignant tumor of the bone?

Metastatic Tumor to the bone
---Increased serum calcium

15

What are the common sites of the primary cancer that metastatizes to the bone?

Breast
Lung
Thyroid
Kidney
Prostate

16

The first tumor of the bone is Osteoid Osteoma (benign). What is the etiology?

Tumor of young males

17

What is the presentation for osteoid osteoma?

Predilection for appendicular skeleton
Nocturnal pain alleviated by aspirin

18

The next benign tumor of mature bone is Osteoma. What is the pathogenesis?

Gardner's syndrome: FAP + multiple osteomas, desmoid tumors and epidermal cysts

19

What is the presentation for osteoma?

Predilection for craniofacial bones

20

The first malignant tumor of the bone is Osteosarcoma. What is the etiology?

Malignant Sarcoma of Osteoblasts (mesenchymal origin) --- lay down osteoid
Mostly Primary: mutation in p53 or Rb
--seen in teenagers (may have a history of bilateral retinoblastoma as a child)
Secondary: following Paget's Disease or radiation
--seen in flat bones of older patients (40-50s)

21

Osteosarcoma affects what part of the bone?

Metaphysis in distal femur/proximal tibia
--around the knee joint

22

What is the presentation for osteosarcoma?

Pathological fracture in whichever bone affected = bone pain
--rapidly enlarging soft tissue mass (tumor invades soft tissue around bone)

23

Explain the anatomical locations for osteosarcoma and the relation to grading?

Intramedullary (low grade)
Intracortical (high grade)
Juxtacortical (low or hight grade)

24

On x-ray what is seen in patients with osteosarcoma? slide 11

Codman's Triangle (elevation of periosteum) and reactive bone formation (sunburst appearance)

25

What is seen on bone biopsy in patients with osteosarcoma? slide 12?

Lace like osteoid laid down malignant osteoblasts

26

What ares the complications of Osteosarcoma?

Aggressive
--can invade and mets through blood --- lungs
-cannon ball lesions on CXR
---hemoptysis and resp failure

27

The first benign tumor of cartilage of metaphysis is Osteochondroma. What is the presentation?

Seen in young adults
-affects bones with endochondral ossification

28

What is the pathogenesis for osteochondroma?

Arises from displaced fragments of the growth plate --clonal proliferation

29

Moving on to the next benign tumor of cartilage of metaphysis is Enchondroma, what is found on xray?

Incidental finding of O ring sign
--cartilage in the middle (radiolucent not calcified)
--tumor surrounded by rim of periosteal bone reaction (White ring)

30

What is the etiology of Enchondroma?

Found in 20-40 year olds
--found in medullary cavity but may erode (Not invade) cortex

31

What is the pathogenesis for enchondroma?

Benign tumor of cartilage (hyaline and myxoid) in metaphysis of short tubular bones of the hands and feet

32

What is the presentation for enchondroma?

Asymptomatic finding on xray

33

What is seen on biopsy (Best investigation) for a enchondroma?

Well differentiated normal chondrocytes

34

What are the complications for enchondroma?

Can lead to pathological fractures = bone pain
Multiple (enchondromatosis) -- increased risk of chondrosarcoma
--Ollier's Disease: multiple enchondromas on one side of the body; 20% develop chondrosarcoma
--Maffucci Syndrome: multiple enchondromas bilaterally -- more disfiguring, chondrosarcoma (20%) and 100% chance of extra articular tumors: soft tissue angiomas, CNS gliomas, and ovarian carcinomas

35

The first malignant tumor of cartilage is chondrosarcoma, what is the etiology?

Malignant tumor of chondrocytes
--affects 30-60 year olds
--can follow Ollier's or Maffuci and arise from metaphysis
--majority arise sporadically from the metaphysis

36

What is the pathogenesis for chondrosarcoma?

Tumor is juxtacortical
Affects axial skeleton: pelvis, proximal humerus and proximal femur

37

What is seen on biopsy in a patient with chondrosarcoma?

Malignant chondrocytes with atypica --- come together to form tumor giant cells
--high N:C ratio
--nuclear hyperchromatism
--form multinucleated tumor giant cells

38

What is seen on x-ray in patient with chondrosarcoma?

Radiolucent mass (b/c its cartilage)

39

What are the complications of a chondrosarcoma?

Bone pain and pathological fractures
-highly invasive -- spreads through blood to lungs -- hemoptysis
De novo is more common
--spreads through medullary cavity and this gives you pancytopenia

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