Detection of fetal keratin with high molecular weight cytokeratin immunostaining in lung biopsy material from a patient with amniotic fluid embolism

Abstract

Abstract. Amniotic fluidembolism (AFE) is a rare and fatal disorder in which the diagnosis can bechallenging for clinicians and pathologists. A healthy 36-year-old woman(gravida 4, para 2) was admitted for delivery in the 40th week of gestation. Atthe fifth minute following birth, during expulsion of the placenta, the patientsuddenly collapsed with bradycardia, shallow respiration, and loss ofconsciousness. After evaluation, an emergent pulmonary embolectomy for acutethrombo-embolism was performed, however the patient could not be weaned fromcardiopulmonary bypass, and died of severe right ventricular dysfunctionfollowing the operation. Microscopic examination of the biopsy materialdetected clearly visible fetal epithelial squames inside pulmonary vessels,both with routine hematoxylin-eosin (HE) staining and immunostaining for highmolecular weight cytokeratin (HMW-CK). The diagnosis of amniotic fluid embolism(AFE) was made, which was confirmed as the cause of death. We show that HMW-CKstaining can be a useful means of detecting amniotic fluid-derived fetalkeratin within alveolar tissue. We suggest that this technique, used inaddition to HE staining and in combination with sudden-onset clinical findings,may increase the accuracy of diagnosis in AFE.Key words: Amniotic fluidembolism, cardiovascular collapse, cytokeratin, high molecular weightcytokeratin, HMW-CK

Keywords

• Amniotic fluid embolism, cardiovascular collapse, cytokeratin, high molecular weight cytokeratin, HMW-CK

References

1. Abenhaim HA, Azoulay L, Kramer MS, Leduc L. Incidence and risk factors of amniotic fluid embolisms: a population-based study on 3 million births in the United States. Am J Obstet Gynecol 2008; 199: 49.e1-8.
2. Knight M; UKOSS. Amniotic fluid embolism: active surveillance versus retrospective database review. Am J Obstet Gynecol 2008; 199: e9. Meyer JR. Embolia pulmonar amnio caseosa. Bra Med 1926; 2: 301-303.
3. Kwon TJ. Amniotic fluid embolism of lung. Korean J Pathol 1994; 28: 651-656.
4. Masson RG, Ruggieri J. Pulmonary microvascular cytology. A new diagnostic application of the pulmonary artery catheter. Chest 1985; 88: 9089
5. Clark SL, Pavlova Z, Greenspoon J, Horenstein J, Phelan JP. Squamous cells in the maternal pulmonary circulation. Am J Obstet Gynecol 1986; 154: 104-106.
6. Porat S, Leibowitz D, Milwidsky A, et al. Transient intracardiac thrombi in amniotic fluid embolism. BJOG 2004; 111: 506-510.
7. Esposito RA, Grossi EA, Coppa G, et al. Successful treatment of postpartum shock caused by amniotic fluid embolism with cardiopulmonary bypass and pulmonary artery thromboembolectomy. Am J Obstet Gynecol 1990; 163: 572-574.