Case 62

A 80 year old female with an adnexal mass.

p16

1. What's the IHC panel you would like to order?

   
   

IHC

• SMA, desmin, H-cadesmin
• Actin
• ALK
• CD34

See All Options

2. The tumor was found to have positivity for p16, actin, and CDK4, what's the diagnosis?

   A: IMT

   B: Myxoid leiomyosarcoma

   C: Dedifferentiated liposarcoma

   D: HGESS

   E: LGESS

   
   

Answer

A challenging case that the origin of the tumor could be soft tissue or ovary. The diffuse positive for p16 can be seen in leiomyosarcoma and dedifferentiated liposarcoma; CDK4 can be positive in well-differentiated or dedifferentiated liposarcoma. THe correct answer is C, as there is no lipogenic area.

References: https://tumourclassification.iarc.who.int/chaptercontent/34/416

Case credit: https://qp.91360.com/9896.html?lang=en

Author: Wangpan Jackson Shi, MD