2020-28 / July 13 (Contributor: Liwei Jia)
A woman in her early 30s presented with flank pain. Subsequent MRI confirmed a mixed solid and cystic renal mass (Bosniak IV) measuring 4 cm in greatest dimension, favored to be a cystic carcinoma. Gross and histological images from the partial nephrectomy specimen are shown below.
Click on the below thumbnails to enlarge photos.
1. What is the diagnosis?
a. Epithelial predominant Wilms tumor
b. Metanephric adenoma
c. Papillary renal cell carcinoma, solid variant
d. Ewing sarcoma
e. Nephrogenic adenoma
2. What immunohistochemistry is most helpful in resolving your differential diagnosis?
3. What is the typical molecular alteration associated with this lesion?
a. EWS-FLI1 gene fusion
b. BAP-1 loss
c. Trisomy 7 and 17
d. BRAF V600E mutatione. VHL mutation