Persistent Gestational Trophoblastic Disease After an Androgenetic/Biparental Fetal Chimera

Abstract

Frozen section is often requested in the intraoperative assessment of patients, presenting with ovarian masses, to provide guidance for appropriate surgical management. To assess the accuracy of frozen section and identify causes of diagnostic error, we reviewed 914 consecutive ovarian frozen sections performed over a 5-year period in 2 laboratories; one of which provides a general surgical pathology service and, the other, a specialist gynecologic pathology service. Cases, in which there were significant diagnostic discrepancies between the intraoperative and the final histological diagnoses, were reviewed. The series included 552 benign lesions (60.4%), 96 borderline (atypical proliferating) epithelial tumors (10.5%), and 266 malignancies (29.1%). The overall accuracy of frozen section diagnosis was 95.3%. There were 43 cases with diagnostic discrepancy; 20 (3.8% cases) of which were reported in the specialist laboratory and 23 (5.9% cases) in the general laboratory. Underdiagnosis of tumor type accounted for 32 of 43 discrepant cases and was most frequent in borderline mucinous tumors. The most common cause of overdiagnosis was the misinterpretation of serous cystadenofibroma as borderline serous tumor. Slide review of the 41 assessable cases indicated that sampling error, pathologist misinterpretation, and suboptimal slide preparations contributed to misdiagnoses in 17, 23, and 9 tumors, respectively (in 9 cases, 2 factors were contributory), whereas no specific error was identified in the remaining case. Technical factors and pathologist misinterpretation were more common in the general pathology laboratory. This study confirms that ovarian frozen section is a generally reliable technique, but there are problematic areas, particularly involving the assessment of borderline tumors.

Contribution of Intraoperative Cytology to the Diagnosis of Ovarian Lesions

“…The procedure selected for diagnosis in intraoperative consultation in this series, which, as already described, includes gross examination, frozen section evaluation, cytological diagnosis in imprint or smear specimens and a cyto-histologic correlation, shows a high percentage of accuracy with the definitive histological diagnosis and also high values of other performance indicators [1,2,3,9,12,13]. …”

“…This rapid intraoperative diagnosis traditionally relies on macroscopic examination and frozen section diagnosis. Many authors report a high percentage of concordance and overall accuracy between frozen section and definitive histological diagnosis, with values ranging from 87 to 96% [1,3,4,5,6,7,8,9]. …”

“…Pathologists recognize the high reliability of frozen section diagnosis, but they are aware of the limitations of this method due to technical, sampling and interpretation problems [1,10]. To overcome these limitations, some pathologists add to the intraoperative diagnosis the information that cytology specimens and cyto-histological correlations provide.…”

“…The demand for intraoperative consultations in the case of ovarian lesions has increased in recent years [1,2]. This rapid intraoperative diagnosis traditionally relies on macroscopic examination and frozen section diagnosis.…”

Mouse chimeras as a system to investigate development, cell and tissue function, disease mechanisms and organ regeneration

“…As the androgenetic cells had genetic contribution from different sperm, this chimera may have formed through fertilization of an anucleate egg with two sperm, and subsequent aggregation with a second zygote. 19 However, such a scenario could also result from uneven distribution of pronuclei during cleavage of a single oocyte fertilized by multiple sperm, a condition that is not strictly chimerism or mosaicism.…”