Casefiles 12: sarcomas

Question 1

most patients with STSs (soft tissue sarcomas) do not present with ?
but some do present with ?

Answer 1

NO regional LAD or systemic symptoms such as weight loss, night sweats, or cachexia

some produce local erythema, pain, and tenderness as the result of tumor necrosis

Question 2

diagnosing sarcomas

Answer 2

core-needle (larger than 14-16 gauge needle)
If the core-needle biopsy is nondiagnostic, an open incisional biopsy should then be performed
NOT excisional biopsy

Question 3

Excisional biopsies of suspected STSs are strongly discouraged because they frequently are associated with ?

Answer 3

positive resection margins, which necessitate additional surgeries for local disease control

Question 4

Once STS is confirmed by biopsy, it is necessary to do what prior to tumor resection?

Answer 4

stage the patient’s disease locally and systemically

MRI, CT for local extent and of chest, abdomen, and pelvis for mets

Question 5

STS treatment

Answer 5

Surgical resection with microscopically clear margins
radiation therapy if stage II or III
some evidence to suggest that patients with high-risk (stage IIB+) STSs may derive some benefits with adjuvant systemic chemo

Question 6

STS staging is based on what?

Answer 6

tumor size (less than/= 5 cm or greater than 5 cm)
depth (superficial or deep to fascia)
nodal involvement (+) or (–)
metastasis (+) or (–)
histologic grade (well-, moderate-, or poorly-differentiated)

Question 7

resection criteria

Answer 7

R2: Surgical resection with gross (+) margin involvement (rarely done, little benefit)
R1: Surgical resection with gross (–) margin but microscopically (+) margin
R0: Surgical resection with microscopically (–) margin (primary goal of surgery)

Question 8

What mutation has been identified in 80% to 85% of GISTs (GI stromal tumors)
5% to 7% of GISTs occur as the result of ?

Answer 8

A gain-of-function mutation in the tyrosine kinase receptor (KIT)

primary platelet-derived growth factor receptor alpha (PDGFRA)

Question 9

Carney’s triad

Answer 9

original: GIST, paraganglioma, and pulmonary chondroma

recent addition of esophageal leiomyoma and adrenal adenoma

Question 10

Tyrosine kinase inhibitors (TKIs)

Answer 10

postoperative adjuvant therapy for high-risk and/or metastatic GISTs (improve resectability)
first-line-imatinib, second-line-sunitinib, and third-line-regorafenib

Question 11

Soft tissue sarcomas (STSs) are a heterogeneous group of solid, mesenchymal cell tumors originating from ?

Answer 11

muscle, fat, vascular tissue, fibrous connective tissue, peripheral neural tissue, and visceral tissue

Question 12

breakdown of STS location

Answer 12

60%: extremities, 20%: truncal region, 15%: intra-abdominal or retroperitoneal, 5%: head and neck region

Question 13

?% of patients with STSs have distant metastases at presentation, with ? being the most common site.

Answer 13

10%

the lungs

Question 14

Currently, the guiding principle in STS surgery is to achieve ? of uninvolved tissue margins or an intact fascia in the resected specimen

Answer 14

greater/= 2.0 cm

Question 15

Known physical factors for sarcoma development include ?

Answer 15

history of radiation, lymphedema, and chemical exposures (including prior chemotherapy)

Question 16

genetic conditions associated with sarcomas

Answer 16

Neurofibromatosis
Li–Fraumeni syndrome
Retinoblastoma
Familial polyposis coli (Gardner syndrome)
p53 and Rb-1 mutations

Question 17

presentation of retroperitoneal sarcomas

diagnose with ?

Answer 17

early satiety and lower extremity venous congestion (compressive, as median size at dx is 15-20cm)
CT/MRI, usually don’t need biopsy, but if uncertainty can use image-guided core needle

Question 18

most retroperitoneal sarcomas are ?

do the metastasize?

Answer 18

liposarcomas

rarely metastasize to distant sites

Question 19

GIST specifically refers to a tumor arising from the GI tract with a ? mutation

Answer 19

KIT or PDGFRA-activating mutation

Question 20

sites of GIST

Answer 20

stomach (50%-70%), small bowel (25%-15%), colon and rectum (5%-10%), omentum (7%), and esophagus (less than 5%)

Question 21

What is the most common symptom related to GISTs, mostly as the result of ?
the most common sites of metastasis are ?

Answer 21

Bleeding due to tumor necrosis

the peritoneum, omentum, and liver

Question 22

imaging modality most commonly used for diagnosis of GIST prior to surgery

Answer 22

CT + contrast, MRI if in rectum/pelvis

Question 23

Most gastric GISTs can be resected by either a ? or ? Small bowel and colorectal GISTs are treated by ?

Answer 23

wedge resection or partial gastrectomy

segmental resections

Question 24

Extremity STSs do not have pathognomonic characteristics based on imaging that can establish diagnosis therefore ? is the only way to determine the diagnosis

Answer 24

Tissue sampling

Question 25

One-year of ? has been found to reduce recurrence following the resection of high-risk GISTs (tumor greater than 3 cm, nongastric origin, and greater than 5-10 mitotic figures/50 HPF)

Answer 25

imatinib adjuvant therapy

*effective only for patients with GISTs with c-kit mutations