Chest wall tumors

Question 1

What are the different chest wall tumor, by tissue origin?

Answer 1

Bone
osteoma/osteosarcoma
-Ewing sarcoma
-PNET
-Osteochondroma

Muscle
-Rhabdomyosarcoma

Cartilage
-chondroma/chondrosarcoma

Vascular
-hemangioma, lymphangioma, angiosarcoma

Soft tissue:
synovial sarcoma, lipoma/liposarcoma, mesenchymal hamartoma, PNET (peripheral neuroectodermal tumor

Question 2

What is infantile fibrosarcoma

Answer 2

Chest wall tumor which can be very extensive. Diagnosed in the neonatal period. responds well to chemo and avoids morbid chest wall resection.

Important to differentiate from mesenchymal hamartoma which can regress spontaneousy w/o chemo.

Question 3

What is a PNET? what is the relation with Ewing sarcoma?

Answer 3

peripheral primitive neuroectodermal tumor. previously called Askin / neuroepithelioma. Same family as Ewing sarcoma with a common origin. Pnet are more differentiated than Ewing.

PNET oc

Like Ewing, can affect bone or soft tissue (less frequent).

Pnets are often posterior thoracic tumors.

Question 4

Should Ewing / Osterosarcoma be approached with upfront surgery or neoadj chemo?

Answer 4

Depends on size and possibility to perform excisional biopsy with negative margins.

< 2 cm : surgery
2-3.5 cm: biopsy vs core
> 3.5 : core (7 passes)

principle of biopsy: do not contaminate pleural space. avoid hemorrhage and spillage.

Question 5

What is the metastatic workup?

Answer 5

Chest CT

Utility of pet is debated.

Question 6

what are the surgical principle of osteo/ewing chest wall resection?

Answer 6

neoadj
> 5 cm 
3 or more ribs involved
invasion spinal canal
invasion vessels mediastium

Do not proceed to muscle sparing if muscles are involve.

1 cm margins are generally accepted for malignant chest wall tumors. concerning the “1 rib above / below” principle, in older children if your intercostal space if > 1 cm, may consider not removing adjacent ribs. remove of fibrous tissues around tumor as they may contain neoplastic cells.

for R1 margins, RMS can receive radiotherapy with similar outcome but will have radiotherapy associated complications RMS require 0.5 cm margins)

Document and resect en bloc pleural/lung involvement. may require pleural radiation.

Question 7

Which chest wall tumors are radiosensible?

Answer 7

Ewing and RMS. Much less for osteo.

Question 8

What do you need to proceed to a chest wall reconstruction?

Answer 8

Related to size of deficit and bulk of muscle.
If large deficit (3 ribs or more), goretex patch can be used. to facilitate fixation, drill holes in rib to allow anchoring.

Question 9

What is a chest wall mesenchymal hamartoma

Answer 9

benign chest wall tumor consisting of .
can be very extensive and resection is associated with large chest wall defect + sanguine surgery.

Bx to confirm dx, and then observation. will regress very slowly (decades). no malignant transformation reported.

Question 10

What are aneurysmal bone cysts?

Answer 10

They are fibrous cysts composed of large vascular channels that expand the bone and can cause pain, swelling and fractures. Cyst-like areas filled with blood may compose a major portion of the mass and produce extensive blood loss when encountered during biopsy or resection.

proceed to surgical resection

Question 11

What are myofibroblastic tumors?

Answer 11

Benign tumors which are composed of myofribroblast, and resolved spontaneously. can be found during infancy and present as thoracic soft tissue tumors.

Question 12

What are the radiological characteristics distinguishing benign chest wall tumors from their malignant counterpart?

Answer 12

expect for mesenchymal hamartoma, they are none. therefore, one should have an appropriate tissue diagnosis.

Question 13

Name 2 chest wall tumors of infancy which should be observed due to spontaneous regression and rare malignant transformation?

Answer 13

mesenchymal hamartoma

myofibromatous tumors of infancy.