HSD3B1, hydroxyl-d-5-steroid dehydrogenase

HSD3B1 catalyses the oxidation of d-5-3-hydroxysteroids to the d-4-3 keto configuration. Western blot analysis shows its expression to be restricted to placenta; it is not expressed by other normal tissues.

Immunohistochemical expression

In early placentas and complete hydatidiform moles, HSD3B1 is highly expressed by syncytiotrophoblast and intermediate trophoblast of the implantation site and the chorion laeve. Expression by trophoblastic columns is very variable. It is not expressed by cytotrophoblast.

normal placenta	trophoblast	21/211
choriocarcinoma	trophoblast	35/351
Placental site trophoblastic tumour	trophoblast	14/141
Epithelioid trophoblastic tumour	trophoblast	18/181
Placental site nodule	trophoblast	19/191
Exaggerated placental site	trophoblast	9/91
Normal endometrium, myometrium and cervix		negative1
Cervix	squamous cell carcinoma	0/861
Cervix	adenocarcinoma	0/161
Endometrium	endometrioid adenocarcinoma	2/59(focal weak positivity)1
	serous adenocarcinoma	0/31
	clear cell carcinoma	0/11
Lung	squamous cell carcinoma	0/411
Lung	adenocarcinoma	0/431
breast	infiltrating ductal carcinoma	1/70(focal weak positivity)1

Diagnostic utility

Diagnosis of trophoblastic tumours.

References

1 Mao TL, Kurman RJ, Jeng YM, et al. HSD3B1 as a novel trophoblast-associated marker that assists in the differential diagnosis of trophoblastic tumors and tumorlike lesions. Am J Surg Pathol 2008; 32:236-42

This page last revised 1.4.2008.