Testis

Question 1

Ipx for adenomatoid tumour

Answer 1

Positive for cytokeratin, calretinin, podoplanin (D2-40), CK5/6, thrombomodulin, WT1

Question 2

Top DD for adenomatoid tumour

Answer 2

Sex cord-stromal tumor, mesothelioma, metastatic carcinoma, epithelioid hemangioma/hemangioendothelioma, yolk sac tumor, leiomyoma/leiomyosarcoma and other sarcomas

Question 3

Ipx for seminoma

Answer 3

Positive for PLAP, OCT3/OCT4, CD117, Podoplanin (D2-40), vimentin, SALL4, NANOG, SOX17
Negative for cytokeratin (may be focal or weak), EMA, α-fetoprotein, HCG, inhibin-α, CD30, glypican-3, SOX2

Question 4

Top DD for seminoma

Answer 4

Embryonal carcinoma, yolk sac tumor, monophasic choriocarcinoma, lymphoma, spermatocytic seminoma, Sertoli cell tumor, nonspecific granulomatous orchitis

Question 5

IPx for choriocarcinoma

Answer 5

Syncytiotrophoblasts are positive for cytokeratin, hCG, HPL, EMA/MUC1, inhibin, glypican-3, CEA, and SALL4
Cytotrophoblasts are (+) for SALL4, GDF3, p63, and GATA3
Negative for vimentin, CD30 (Ber-H2), podoplanin (D2-40), and OCT3/4

Question 6

Ipx for Leydig cell

Answer 6

Positive for inhibin-α, calretinin, Melan-A (MART-1), WT1, androgenic hormones (P450scc, 3β-HSD, etc.), CD99, steroidogenic factor (SF-1), and vimentin (strong and diffuse)
Negative for cytokeratin, chromogranin, and synaptophysin (rarely focally positive for these 3 markers), S100 and PLAP (rarely positive for these 2 markers), nuclear beta-catenin, germ cell tumor markers

Question 7

IPx for testicular tumour of adenogenital syndrome

Answer 7

Positive for inhibin, Melan-A (MART-1), CD56, and synaptophysin

Question 8

DD for testicular tumour of adenogenital syndrome

Answer 8

Leydig cell tumor
Leydig cell hyperplasia
Steroid cell nodules with other adrenal diseases

Question 9

Ancillary Tests for sertoli cell tumour

Answer 9

Inhibin, SF1, and calretinin (+)
AE1/AE3, CAM5.2, vimentin, CD99, WT1, NSE, and CD56 frequently (+)
EMA, PAX8, CK7, GATA3, and chromogranin typically (-)
DICER1 mutations