Clinical history
22 year old man, testicular mass.
Primary image
Very low magnification. H&E stain.
Very high magnification

Very high magnification. H&E stain.

Very high magnification

Very high magnification. H&E stain.

Differential diagnosis
Additional tests
More history
More history

Discovered testicular mass on selfexam. Serum hCG elevated.

Ask a friend
Ask a friend

Can't help think about chorionic villi. Did you try a hCG IHC?

Stains
Alcian blue/PAS to Bilirubin 

Test  Result 
Alcian blue/PAS  Dr T would ask why! 
Alican blue pH 1.0  Dr T would ask why! 
Alcian blue pH 2.5  Dr T would ask why! 
Auramine  Dr T would ask why! 
Bielchowsky  Dr T would ask why! 
Bilirubin  Dr T would ask why! 



Colloidal iron to FontanaMasson 

Test  Result 
Colloidal iron  Dr T would ask why! 
Congo red  Dr T would ask why! 
Cresyl violet  Dr T would ask why! 
Dieterle  Dr T would ask why! 
Diff Quik  Dr T would ask why! 
FontanaMasson  Dr T would ask why! 



Gallyas to Gremelius 

Test  Result 
Gallyas  Dr T would ask why! 
Giemsa  Dr T would ask why! 
GMS  Dr T would ask why! 
Gomori's trichrome  Dr T would ask why! 
Gram  Dr T would ask why! 
Gremelius  Dr T would ask why! 



JMS to Mucicarmine 

Test  Result 
JMS  Dr T would ask why! 
Jones  Dr T would ask why! 
Kinyoun  Dr T would ask why! 
Luxol fast blue  Dr T would ask why! 
Masson trichrome  Dr T would ask why! 
MMAS  Dr T would ask why! 
Movat  Dr T would ask why! 
Mucicarmine  Dr T would ask why! 



Oil red O to Prussian blue 

Test  Result 
Oil red O  Dr T would ask why! 
Orecein  Dr T would ask why! 
PAS  Dr T would ask why! 
PASD  Dr T would ask why! 
PASF  Dr T would ask why! 
PTAH  Dr T would ask why! 
Prussian blue  Dr T would ask why! 



Reticulin to ZiehlNeelsen 

Test  Result 
Reticulin  Dr T would ask why! 
Sudan black B  Dr T would ask why! 
Toluidine blue  Dr T would ask why! 
Verhoeff  Dr T would ask why! 
Von Kossa  Dr T would ask why! 
WarthinStarry  Dr T would ask why! 
ZiehlNeeslen  Dr T would ask why! 



IHC
Alpha1 AT to Cathepsin K 

Test  Result 
alpha1 AT  Dr T would ask why! 
ACTH  Dr T would ask why! 
AE1/AE1  Dr T would ask why! 
alphafetoprotein  Dr T would ask why! 
AlkI  Dr T would ask why! 
AMACR  Dr T would ask why! 
AR  Dr T would ask why! 
ATRX  Dr T would ask why! 
Beta2microglobulin  Dr T would ask why! 
B72.3  Dr T would ask why! 
Betacatenin  Dr T would ask why! 
BCL2  Dr T would ask why! 
BCL6  Dr T would ask why! 
BCLxL  Dr T would ask why! 
C3 comp  Dr T would ask why! 
CA9  Dr T would ask why! 
Calcitonin  Dr T would ask why! 
Calponin  Dr T would ask why! 
Calretinin  Dr T would ask why! 
CAM5.2  Dr T would ask why! 
Cathepsin K  Dr T would ask why! 



CD10 to Chromogranin 

Test  Result 
CD10  Dr T would ask why! 
CD117  Dr T would ask why! 
CD138  Dr T would ask why! 
CD15  Dr T would ask why! 
CD1a  Dr T would ask why! 
CD20  Dr T would ask why! 
CD21  Dr T would ask why! 
CD23  Dr T would ask why! 
CD3  Dr T would ask why! 
CD30  Dr T would ask why! 
CD31  Dr T would ask why! 
CD34  Dr T would ask why! 
CD35  Dr T would ask why! 
CD4  Dr T would ask why! 
CD43  Dr T would ask why! 
CD45 (LCA)  Dr T would ask why! 
CD5  Dr T would ask why! 
CD56  Dr T would ask why! 
CD57  Dr T would ask why! 
CD68  Dr T would ask why! 
CD7  Dr T would ask why! 
CD79a  Dr T would ask why! 
CD8  Dr T would ask why! 
CD99  Dr T would ask why! 
CDX2  Dr T would ask why! 
CEAm  Dr T would ask why! 
Chromogranin  Dr T would ask why! 



CK17 to Glypican 3 

Test  Result 
CK17  Dr T would ask why! 
CK19  POSITIVE 
CK20  Dr T would ask why! 
CK34betaE12  Dr T would ask why! 
CK5/6  Dr T would ask why! 
CK7  Dr T would ask why! 
CMV  Dr T would ask why! 
cMYC  Dr T would ask why! 
Cyclin D1  Dr T would ask why! 
D240  Dr T would ask why! 
Desmin  Dr T would ask why! 
DOG1  Dr T would ask why! 
EBV  Dr T would ask why! 
EMA  Dr T would ask why! 
ER and PR  Dr T would ask why! 
Factor VIII  Dr T would ask why! 
Factor XIIIa  Dr T would ask why! 
Fascin  Dr T would ask why! 
FH  Dr T would ask why! 
FSH  Dr T would ask why! 
Gastrin  Dr T would ask why! 
GATA3  POSITIVE nuclear staining 
GCDFP15 (BRST2)  Dr T would ask why! 
GFAP  Dr T would ask why! 
GH  Dr T would ask why! 
Glucagon  Dr T would ask why! 
Glypican3  POSITIVE 



HBME1 to IgM 

Test  Result 
HBME1  Dr T would ask why! 
HBV core  Dr T would ask why! 
HBV surface  Dr T would ask why! 
Hcaldesmon  Dr T would ask why! 
HCG  POSITIVE 
Helicobacter  Dr T would ask why! 
Hepatocyte  Dr T would ask why! 
HER2/neu  Dr T would ask why! 
HHV8  Dr T would ask why! 
HMB45  Dr T would ask why! 
HNF1beta  Dr T would ask why! 
HPV  Dr T would ask why! 
HSVI  Dr T would ask why! 
HSVII  Dr T would ask why! 
IDH1  Dr T would ask why! 
Inhibin  Dr T would ask why! 
INI1 (BAF47)  Dr T would ask why! 
Insulin  Dr T would ask why! 
Kappa  Dr T would ask why! 
Ki67  40% 
Lambda  Dr T would ask why! 
Leu 7  Dr T would ask why! 
IgA  Dr T would ask why! 
IgG  Dr T would ask why! 
IgM  Dr T would ask why! 



LH to PDGFR 

Test  Result 
LH  Dr T would ask why! 
LIN28  Dr T would ask why! 
Lysozyme  Dr T would ask why! 
mammoglobin  Dr T would ask why! 
MAP2  Dr T would ask why! 
MCV  Dr T would ask why! 
Melanin A  Dr T would ask why! 
MHC class I  Dr T would ask why! 
MITF  Dr T would ask why! 
MUM1  Dr T would ask why! 
Myeloperoxidase  Dr T would ask why! 
MYO D1  Dr T would ask why! 
Myoglobin  Dr T would ask why! 
Napsin  Dr T would ask why! 
NF  Dr T would ask why! 
NKX3.1  Dr T would ask why! 
NSE  Dr T would ask why! 
OCT3/4  Dr T would ask why! 
p16  Dr T would ask why! 
P501S  Dr T would ask why! 
p53  Dr T would ask why! 
p57  Dr T would ask why! 
p63  Dr T would ask why! 
Pankeratin  Dr T would ask why! 
PAX2  Dr T would ask why! 
PAX5  Dr T would ask why! 
PAX8  Dr T would ask why! 
PCNA  Dr T would ask why! 
PDGFR  Dr T would ask why! 



PLAP to WT1 

Test  Result 
PLAP  Dr T would ask why! 
PNL2C  Dr T would ask why! 
Prolactin  Dr T would ask why! 
PSA  Dr T would ask why! 
PSAP  Dr T would ask why! 
RCC  Dr T would ask why! 
S100  Dr T would ask why! 
SALL4  Dr T would ask why! 
Smooth muscle actin  Dr T would ask why! 
Somatostatin  Dr T would ask why! 
STAT6  Dr T would ask why! 
Synaptophysin  Dr T would ask why! 
TdT  Dr T would ask why! 
TFE3  Dr T would ask why! 
TFEB  Dr T would ask why! 
Thyroglobulin  Dr T would ask why! 
Toxoplasma  Dr T would ask why! 
TSH  Dr T would ask why! 
TTF1  Dr T would ask why! 
Ubiquitin  Dr T would ask why! 
UCHL1 (PGP9.5)  Dr T would ask why! 
Ulex Europaeus  Dr T would ask why! 
Vimentin  Dr T would ask why! 
VIP  Dr T would ask why! 
VZV  Dr T would ask why! 
WT1  Dr T would ask why! 



Chromosomal translocations
Translocations Chr 110 

Test  Result 
t(1;13) PAX7FKHR  Dr Torres would ask why! 
t(2,13) PAX3FKHR  Dr Torres would ask why! 
t(8;14) MYCIGH  Dr Torres would ask why! 
t(9;22) BCRABL  Dr Torres would ask why! 
t(9;22) CHNEWS  Dr Torres would ask why! 



Translocations Chr 1113 

Test  Result 
t(11;14) CCND1IGH  Dr Torres would ask why! 
t(11;22) EWSWT1  Dr Torres would ask why! 
t(11;22) FLI1EWS  Dr Torres would ask why! 
t(12;15) ETV6NTRK3  Dr Torres would ask why! 
t(12;16) FUSATF1  Dr Torres would ask why! 
t(12;16) CHOPTLS  Dr Torres would ask why! 
t(12;22) EWSATF1  Dr Torres would ask why! 



Translocations Chr 1422 

Test  Result 
t(14,18) IGHBCL2  Dr Torres would ask why! 
t(15;17) PMLRARA  Dr Torres would ask why! 
t(16;21) FUSERG  Dr Torres would ask why! 
t(17;22) COLA1PDGFB  Dr Torres would ask why! 
t(21;22) EWSERG  Dr Torres would ask why! 



Translocations Chr X & Y 

Test  Result 
t(X;1) PRCCTFE3  Dr Torres would ask why! 
t(X;17) TFE3ASPL  Dr Torres would ask why! 
t(X;18) SYTSSX  Dr Torres would ask why! 



Diagnosis
Diagnosis

Choriocarcinoma
Comment:
Histology is important for this diagnosis. CK19 is positive in yolk sac tumour (YST) and choriocarcinoma.^{[1]} Glypican 3 is can be positive in choriocarcinoma; it is usually positive in YST.
Reference
 ↑ Bremmer, F.; Ströbel, P.; Hubertus, H.; Strecker, J.; Gaisa, N.; Strauß, A.; Schweyer, S.; Radzun, HJ. et al. (2015). [www.diagnosticpathology.org/content/10/1/7Cached "CK19 is a sensitive marker for yolk sac tumours of the testis."]. Diagnostic Pathology 10 (7). doi:10.1186/s130000150243y. www.diagnosticpathology.org/content/10/1/7Cached.

Other cases


 Number  

 Subspecialty (Difficulty) 
Autopsy pathology (jr,sr, f/e)
Breast pathology (jr,sr, f/e)
Cardiovascular pathology (jr,sr, f/e)
Cytopathology (jr,sr, f/e)
Dermatopathology (jr,sr, f/e)
Endocrine pathology (jr,sr, f/e)
Forensic pathology (jr,sr, f/e)
Gastrointestinal pathology (jr,sr, f/e)
Genitourinary pathology (jr,sr, f/e)
Gynecologic pathology (jr,sr, f/e)
Hematopathology (jr,sr, f/e)
Head and neck pathology (jr,sr, f/e)
Lymph node pathology (jr,sr, f/e)
Medical kidney pathology (jr,sr, f/e)
Molecular pathology (jr,sr, f/e)
Neuropathology (jr,sr, f/e)
Pediatric pathology (jr,sr, f/e)
Pulmonary pathology (jr,sr, f/e)
Placental pathology (jr,sr, f/e)
Soft tissue pathology (jr,sr, f/e) 

 Difficulty  

