CASE OF THE WEEK
2021-46/November 15
Contributors: Ankur Sangoi
A man in his 40s with 5.3cm testicular mass grossly extending into hilar soft tissue. Section of central mass shown.
Quiz
1. What is the correct diagnosis?
a. Yolk sac tumor
b. Embryonal Carcinoma
c. Microcystic Pattern of Seminoma
d. Sertoli cell tumor
2. What is the correct diagnosis?
a. OCT3/4 positive, glypican3 positive, SF1 negative
b. OCT3/4 negative, glypican3 negative, SF1 positive
c. OCT3/4 negative, glypican3 positive, SF1 negative
d. OCT3/4 positive, glypican3 negative, SF1 negative
1. c; 2. d
Microcystic pattern of seminoma.
The correct diagnosis is microcystic pattern seminoma (additional sections showed traditional pattern seminoma).The immunoprofile as expected in this case was OCT3/4 positive, glypican3 negative, SF1 negative.
The main differential diagnosis is with yolk sac tumor, although sex cord stromal tumor (Sertoli cell tumor) could also be considered. While immunohistochemistry can usually resolve the differential diagnosis, typically awareness of this unusual morphologic pattern of pattern of seminoma is sufficient for correct diagnosis.A useful morphologic comparative clue from microcystic pattern seminoma is that the spaces in yolk sac tumor are more irregular and frequently anastomose and show flattened nuclei lacking prominent nucleoli.
UlbrightTM, Young RH. Seminoma with tubular, microcystic, and related patterns: a study of 28 cases of unusual morphologic variants that often cause confusion with yolk sac tumor. Am J Surg Pathol. 2005 Apr;29(4):500-5.
Ankur Sangoi
El Camino Hospital
Mountain View, California
Testis
testis, seminoma, microcystic