2020-18 / May 4 (Contributor: Stephen Rohan)
The patient in his 40s presented with a complaint of a right testicular mass. Ultrasound revealed a 2.0 cm cystic mass. Serum tumor markers (HCG, AFP, LDH) were all normal. Positive immunohistochemical stains are shown. Additional stains performed (all negative) included CK5/6, calretinin, and OCT4.
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1. What is the correct diagnosis?
a. Mesothelial hyperplasia
b. Malignant mesothelioma
c. Serous borderline tumor / atypical proliferative serous tumor of the para-testis
d. Metastatic carcinoma
e. Embryonal carcinoma