L18. Bone and Soft Tissue Pathology III

Osteoid Osteoma is lesion of --- bone

cortical

Osteiod osteoma is a --- type of tumor

benign

Osteoblastoma is a --- type of tumor

benign

Osteosarcoma is ---

malignant

True / False: bone forming tumors occur in young patients

true - within first 3 decades of life

What population is mainly affected by bone forming tumors?

young males

= first 3 decades of life

Osteoid osteoma occur primarily in --- and ---

tibia and femur

What is the characteristic focus of osteoid osteoma?

Nidus

- radioopaque in the center

- radioluscent in the periphery

Osteosarcoma affects what regions of the body?

metaphysis of long bones

knee (50%)

mandible/maxilla

Osteosarcoma pathogenesis

acquired genetic mutation

mutation in retinoblastoma gene

TP53 mutation = Li Fraumeni

What condition significantly increases the risk of osteosarcoma?

Paget's disease = excessive bone resorption + abnormal bone formation

results in dense thick disorganized bone structure

What hereditary diseases increase risk of osteosarcoma?

somatic mutation in retinoblastoma gene

TP53 mutation = Li Fraumeni

Retinoblastoma gene is a cell cycle ---

regulator

What significantly increases the risk of osteosarcoma? (by 1000x)

somatic mutation in retinoblastoma gene

Li Fraumeni syndrome

TP53 mutation

--- and --- are over-expressed in low grade osteosarcoma

MDM2 and CDK4 (cell cycle regulators)

True / False: if an osteochondroma breaks through the periosteum, it can be a sign of malignant transformation, typically into a chondrosarcoma

true

What is a consideration of malignancy?

tumor destroying underlying tissue

Osteosarcoma is a malignant tumor that produces --

cartilage

Chondroid tumors occur in --- but result in the deposition of ---

form in bone

result in deposition of hyaline cartilage

Osteochondroma

benign bone tumor with a cartilage cap

What are the structures present in osteochondroma?

cartilage cap (<2mm) + trabecular bone + medullary cavity

In osteochondroma the cartilage cap is ---

< 2cm (generally a few mm and tend to decrease with age)

Osteochondroma is also called

exostosis

In osteochondroma the cartilage cap resembles the --- of a long bone

end (epiphysis)

Osteochondroma is a --- type of cartilaginous tumor

benign

Osteochondroma is 85% --- meaning that it is the only tumor found in the affected area or body region

solitary =

Which is a cartilage capped bony outgrowth that developed via endochondral ossification but in the wrong direction: osteochondroma or chondroma

osteochondroma

Hereditary multiple osteochondromas (exostoses) are caused by ---

mutations in EXT1 or EXT 2 genes

What does mutations in EXT1 or EXT2 gene cause?

hereditary multiple osteochondroma

Hereditary multiple osteochondroma increases risk of ---

malignant transformation

Chondroma

being tumor composed of hyaline cartilage

Chrondroma is a --- type of cartilaginous tumor

benign

Chondroma is also called ---

enchondroma

Chondroma versus enchondroma

chondroma = surface of bone

enchondorma = inside medullary cavity

Which is inside the medullary cavity (within bone): chondroma or enchondroma?

enchondroma

Chondrosarcoma

malignant tumor of cartilage-producing cells

Ollier syndrome

multiple enchondromas

Maffuci syndrome

multiple enchondroma + soft tissue vascular tumor

Chondroma affects mainly --- and ---

hands and feet

True / False: chondroma present as painless small bumps with no fractures

true

Secondary chondrosarcoma

maligant tumor that rises on pre-existing benign lesion (osteochondroma or chondroma)

chondrosacroma = malignant tumor

What increases risk of secondary chondrosarcoma?

Ollier syndorme or maffuci syndrome = multiple chondromas

The risk for developing secondary chondrosarcoma from multiple osteochondromas is --- %

2%

The risk for developing secondary chondrosarcoma from multiple enchondromas is --- to ---%

2 - 20%

Grade 1 tumors have relatively ---

low cellularity

Tumors vary in cellularity, cytologic atypia, and mitotic activity. They are assigned a grade from

1 - 3

Grade 3 tumors have ---, extreme pleomorphism with bizarre tumor giant cells, mitoses, and necrosis

high cellularity

What tumors rarely metastasize: osteochondromas, chondromas, or chondrosacroma

grade 1 chondrosarcomas rarely metastasize

grade 2 chondrosarcomas spread hematogenously, especially to lungs

Non-ossifying fibroma

Faulty ossification of bone during development

Fibrous dysplasia

gain of function mutation in GNAS-1 gene

----- is composed of curvilinear trabecylae of woven bone surrounded by a moderately cellular fibroblastic proliferation

fibrous dysplasia

Ewing Sarcoma

rare malignant tumor arising in bone; most often occurring in children

11:22 translocation

Ewing sarcoma is known as a small --- cell tumor

round blue

What tumors are most common in adults:

adenocarcinoma of breast, prostate, lung, kidney

What tumors are most common in children:

neuroblastoma, wilms, rhabdomycosacroma

Metastases to bone most often involve the ---

vertebral column

Soft tissue tumors

-Hodgkin disease

-Non-Hodgkin Lymphoma

-Rhabdomyosarcoma

-Retinoblastoma

Bone tumors and soft tissue tumors are classified as

benign

intermediate

malignant

MDM2 and CDK are diagnostic markers in both --- and ---

osteosarcoma and liposarcoma

Liposarcoma

cancer of fatty tissue

pleomorphic highly atypical cells

Liposarcoma is myxoid translocation of --- and ---

12 and 16

Fibromas

benign tumors of fibrous tissue

Leiomyoma

benign smooth muscle tumor

Leimyosarcoma

malignant smooth muscle tumor

Smooth muscle includes

uterus

retroperitoneum

GI

vessel walls

Rhabdomyoma

benign tumor of skeletal muscle

Rhabdomyosarcoma

malignant tumor of skeletal muscle

What rhabdomyoma is more common in adults?

pleomorphic rhabdomyosarcoma

What rhabdomyoma is more common in children?

embryonal rhabdomyosarcoma

alveolar rhabdomyosarcoma

Intramembranous ossification occurs primarily in which of the following?

A. Femur

B. Humerus

C. Mandible

D. Tibia

C. Mandible

The ---- and --- develop through intramembranous ossification from mesenchymal tissue

mandible and cranial bones