Ch. 26 Malignant Tumors/Soft Tissue Tumors

Question 1

What is the most common type of malignant tumor of the bone?

Answer 1

Metastatic Tumors (much more common that any primary tumor)
Some common types in children: rhabdomyocarcoma, neuroblastoma, Wilms tumor and clear cell kidney sarcoma

Question 2

What are the two types of metastatic tumors of the bone? Example of each?

Answer 2

Osteolytic lesions (thyroid, GI, kidney, neuroblastoma) and osteoblastic lesions (PROSTATE, breast, lung, stomach)

Question 3

Malignant proliferation of bone that represents 1/5 of all bone cancers. Most frequent in children age 10-20 and occurs in the elderly. Name that bone disease! What are some risk factors children and elderly to develop (hint: they aren’t the same risk factors)
Pathology report?
Radiology report?
What bone/bone area is commonly involved?

Answer 3

Osteosarcoma
Children: Rb mutation (history of retinoblastoma means watch out for this), p53 also (less common)
Elderly: Paget disease of the bone and radiation exposure (fibrous dysplasia, osteomyelitis, and bone infarcts also increase risk)
Path: Large pleomorphic cells laying down osteoid (pink matrix)
Radiology: Drags periosteum off the bone, forming Codman triangle (w/ sunburst periosteal reaction)
Bone: distal femur proximal tibia (knee region) at the metaphysis

Question 4

Cancer of the intramedullary bone. Most common in the pelvis or central skeleton (shoulder and ribs included).
What is something unique about the prognosis?
Can develop from what disease?

Answer 4

Chondrosarcoma (malignant cartilage tumor)
Survival closely correlated with GRADE
Ollier disease/enchondromatosis (nodular masses of hyaline cartilage)

Question 5

Multinucleated giant cell/stromal cell tumor that occurs in young adults. Most common site? X-ray appearence? Genes related? Recurrence?

Answer 5

Giant Cell tumor
Epiphysis
Soap bubble appearence
p53/c-myc (excess RANK-L as well)
Locally aggressive (especially following resection)

Question 6

Malignant proliferation of poorly differentiated cells from the neuroectoderm with “onion skin” appearance on X-ray. Name that cancer!
Who gets it most commonly?
Where?
Most common site of metastasis?
I bet you know some facts about genetics too!

Answer 6

Ewing sarcoma (Homer-Wright rosettes/small round blue cells)
Don’t confuse with lymphoma or osteomyelitis
Diaphysis of long bones usually in male children
Skull is most common metastasis site (catch it with chemo early as it responds well)
11;22 EWS1/FLI-1 fusion gene

Question 7

Most common “primary” cancer of bone producing lytic lesions. What is the most likely cause of death?

Answer 7

Multiple Myeloma

Renal failure or infection

Question 8

Most frequent sarcoma encountered after radiation therapy with a spindle-shaped tumor and irregular whorled (storiform) pattern on biopsy.

Answer 8

Malignant Fibrous Histiocytoma (Undifferentiated Pleomorphic Sarcoma)
Has foci of macrophage differentiation and spindle cells are well differentiated and resemble fibroblasts

Question 9

Highly malignant soft tissue tumor arising in the joint (particularly the knee). Spindle-shaped mesenchymal cells and CUBOIDAL epithelial like cells

Answer 9

Synovial sarcoma
Emphasis on the cuboidal since these are synovium secreting cells

Shanley also made a big deal out of these not being small round blue cell tumors so take that as you will!

Question 10

Rapid fire!

1. Most common benign soft tissue tumor closely resembling normal fat
2. Most common soft tissue sarcoma of children and young adults
3. 2nd most common malignant sarcoma (Pathoma says most common) in adults with lipoblast as characteristic cell
4. Most frequent neoplasm of infancy and childhood
5. Soft tissue tumor associated with tuberous sclerosis that is in the cardiac tissue
6. Tumor of smooth muscle composed of intersecting fascicles of relatively uniform spindle cells with cigar shaped nuclei

Answer 10

1. Lipoma
2. Rhabdomyosarcoma
3. Liposarcoma (univacuolated/multivacuolated cytoplasmic fat vesicles indenting the nucleus=lipoblast)
4. Hemangioma (Fun fact: angiosarcoma is among the rarest of soft tissue tumors that are most common in elderly…..isn’t science fun)
5. Rhabdomyoma
6. Leiomyoma

Question 11

THROWBACK! Then again, technically nothing is a throwback anymore with tests approaching (I wouldn’t be hurt in the slightest if you throw something at me tomorrow for that one)
Rhabdomyoblasts with striations in the cells that are desmin positive in a little girl with unexplained vaginal spotting. What else might you see?

Answer 11

Sarcoma botryoides/embryonal rhabdomyosarcoma

Presence of polypoid, grape-like tumor masses protruding from the vagina