Clinical history: 21 year old male with abdominal cavity mass and lung mets.
What is the most probable diagnosis?
Desmoplastic small round cell tumor (DSRCT)
You are seeing nests and cords of small blue cells in a highly desmoplastic stroma. The cells have very little cytoplasm, have round nuclei with finely dispersed chromatin, and one or two nucleoli. Tumors are often mitotically active and can show single cell or comedo necrosis.
For exams know:
It is in you Ddx for small round blue cell tumors
It often presents as a mass in the abdominal or pelvic cavity or the testicles
It almost always occurs in males in their twenties and thirties
It is very aggressive and often wildly metastatic
It spreads along serosal surfaces
It has a pathogenic balanced translocation t(11;22)(p13; q12), which fuses the N-terminus of the Ewing sarcoma (EWS) gene (exons 5-9) to the C-terminus (last 3 exons) of the Wilms tumor (WT1) gene
Multimodality therapy is essential with aggressive surgery, chemotherapy and radiotherapy