Touch Preps of Products of Conception for Rule-Out Ectopic Pregnancy:  A Viable Alternative to Frozen Section.
OBJECTIVE
Tissue confirmation of the intrauterine location of a pregnancy can be difficult grossly, necessitating a frozen section diagnosis. First-trimester tissue is often scant and can be exhausted by frozen section. We examined 39 endometrial curettings performed for rule-out ectopic pregnancy by touch prep to examine the utility of cytopathology in documenting trophoblast or chorionic villi (products of conception [POC]).


METHODS
First-trimester curettage specimens sent to the Massachusetts General Hospital Pathology Departmentreceived a gross examination followed by a touch prep of the area most suspicious for villi. Touch preps were reviewed blinded to the final diagnosis and then compared.


RESULTS
Thirty-three of the 39 touch preps and histology specimens were concordant, including all 11 negative histology specimens and 22 of the 28 positive histology specimens.


CONCLUSIONS
POC can be diagnosed by touch prep and may offer confirmation of grossly identified villi. Positive predictive value is 100%. Negative touch preps should receive further evaluation.
From the Department of Pathology, Massachusetts General Hospital, Boston.
Athena L
AL
Chen
From the Department of Pathology, Massachusetts General Hospital, Boston.
Rosemary H
RH
Tambouret
From the Department of Pathology, Massachusetts General Hospital, Boston.
Drucilla J
DJ
Roberts
D000328:Adult; D003581:Cytodiagnosis / Q000379:methods*; D005260:Female; D005629:Frozen Sections; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis*
Cytopathology; Ectopic pregnancy; Touch prep