Quiz-summary
0 of 1 questions completed
Questions:
- 1
Information
Presented by Pedram Argani, M.D. and prepared by Hillary Ross, M.D.
Case 2: This is a 54 year old female with a 6 cm small bowel mass.
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading...
You must sign in or sign up to start the quiz.
You have to finish following quiz, to start this quiz:
Results
Time has elapsed
Categories
- Not categorized 0%
- 1
- Answered
- Review
-
Question 1 of 1
1. Question
Week 435: Case 2
This is a 54 year old female with a 6 cm small bowel mass.images/1alex/05102010case2image1.jpg
images/1alex/05102010case2image2.jpg
images/1alex/05102010case2image3.jpg
images/1alex/05102010case2image4.jpg
images/1alex/05102010case2image5.jpgCorrect
Answer: Dedifferentiated liposarcoma
Histology: This is a somewhat bland spindle cell proliferation that involves the wall of the small bowel. In much of the lesion the cells are fairly uniform, though the nuclei are hyperchromatic. However, in other areas of the lesion, marked nuclear pleomorphism is identified. The neoplastic cells label for both CD34 and CD117, suggesting the possibility of a gastrointestinal stromal tumor. However, the marked pleomorphism seen focally within the lesion is uncommon in GIST. Further sampling of the fat surrounding this lesion reveals the typical pattern of a lipoma-like well-differentiated liposarcoma.
Immunohistochemistry for MDM2 reveals nuclear labeling in the spindle neoplasm as well as the lipoma-like liposarcoma.
Therefore, the lesion is best interpreted as a dedifferentiated liposarcoma simulating a gastrointestinal stromal tumor.
Discussion: Gastrointestinal stromal tumors are usually not pleomorphic, and the presence of a liposarcoma component at the periphery argues against this diagnosis. Solitary fibrous tumor typically does not label for CD117, and would not be associated with a liposarcoma component. Melanoma could potentially label for CD117; however, labeling for CD34 would be unusual, and the liposarcoma surrounding lesion would be difficult to explain.
Incorrect
Answer: Dedifferentiated liposarcoma
Histology: This is a somewhat bland spindle cell proliferation that involves the wall of the small bowel. In much of the lesion the cells are fairly uniform, though the nuclei are hyperchromatic. However, in other areas of the lesion, marked nuclear pleomorphism is identified. The neoplastic cells label for both CD34 and CD117, suggesting the possibility of a gastrointestinal stromal tumor. However, the marked pleomorphism seen focally within the lesion is uncommon in GIST. Further sampling of the fat surrounding this lesion reveals the typical pattern of a lipoma-like well-differentiated liposarcoma.
Immunohistochemistry for MDM2 reveals nuclear labeling in the spindle neoplasm as well as the lipoma-like liposarcoma.
Therefore, the lesion is best interpreted as a dedifferentiated liposarcoma simulating a gastrointestinal stromal tumor.
Discussion: Gastrointestinal stromal tumors are usually not pleomorphic, and the presence of a liposarcoma component at the periphery argues against this diagnosis. Solitary fibrous tumor typically does not label for CD117, and would not be associated with a liposarcoma component. Melanoma could potentially label for CD117; however, labeling for CD34 would be unusual, and the liposarcoma surrounding lesion would be difficult to explain.
