Applications of monoclonal anti-human inhibin alpha subunit in endometrial curettings

Use of reticulin stain in the diagnosis of intra-uterine gestation

AIMS

The diagnosis of intra-uterine gestation may be problematic when specimens from clinically suspected products of conception lack chorionic villi and/or fetal somatic tissues, since the distinction of intermediate trophoblast from decidual or myometrial elements can be difficult. The placental site is also characterised by stromal changes, including the deposition of a characteristic extracellular fibrinoid matrix. We have noted that these stromal changes may be highlighted by a simple reticulin stain; therefore, we have evaluated reticulin staining in a series of endometrial biopsy specimens from patients with intra-uterine and ectopic gestations.

METHODS

Reticulin staining was performed in 28 endometrial specimens from patients with first trimester intra-uterine gestations, including 14 cases that lacked chorionic elements. Eight endometrial samples from patients with concurrent histologically verified tubal ectopic pregnancy were also examined. Selected cases were also studied using a Masson trichrome stain, and immunohistochemically with antisera to cytokeratin and HPL.

RESULTS

There was a distinct increase in reticulin staining, usually evident at low power magnification, in most areas of decidua showing implantation site. Prominent reticulin staining was present around the decidual and trophoblast cells and there was also accentuation around stromal vessels, glands and myometrial cells. There was no clear difference in staining within areas of decidua including only rare intermediate trophoblast cells but this pattern was seldom seen in isolation. Minimal changes were seen in the placental site using the Masson trichrome stain.

CONCLUSION

Reticulin stains may prove useful in the assessment of endometrial specimens from patients with purported intra-uterine gestations when chorionic elements are not identified. Since the staining technique is simple and can be quickly performed, it could be used as an adjunct to conventional H&E assessment and to select appropriate specimen blocks for additional more sensitive studies, including immunohistochemistry.

Subinvolution of the placental site as an anatomic cause of postpartum uterine bleeding: a review

CONTEXT

Subinvolution of the placental site is an anatomic cause of delayed postpartum uterine bleeding that may be underrecognized by general surgical pathologists.

OBJECTIVE

To review the physiology of uteroplacental arterial development and normal postpartum involution, and to present the characteristic clinical and histopathologic features of subinvolution.

DATA SOURCES

Literature review (MEDLINE via PubMed and Ovid) regarding the pathology and pathophysiology of placental site subinvolution. Review of the clinical and pathologic characteristics of our own institution's previously diagnosed cases of subinvolution from hysterectomy and endomyometrial curettage specimens.

CONCLUSIONS

Surgical pathologists must be aware of the cardinal histopathologic findings of subinvolution, and this diagnosis must be considered in every postpartum curettage or hysterectomy specimen presented to the surgical pathologist. Subinvolution of the placental site is an important diagnosis, as this process implies an idiopathic cause, rather than an iatrogenic cause, of postpartum uterine bleeding. The etiology of placental site subinvolution remains poorly characterized.