**34. Prognosis**

AFE accounts for approximately 10% of all maternal death within the USA (Atrash et al., 1990). Case fatality rate has declined significantly in recent years due to the prompt and aggressive resuscitation measures. (Abenhaim et al., 2008; Benson, 1993; Clark et al., 1995; Morgan, 1979). There is higher likelihood of survival if the women survive long enough to

Non-Thrombotic Pulmonary Embolism 95

1992). Despite the relative prevalence at autopsy, the diagnosis is infrequently made ante mortem and thus the incidence of clinically significant tumor embolism is unclear (C. K. Chan et al., 1987). Retrospective chart reviews demonstrate that only 8% of patients with pathological evidence of tumor emboli have documented morbidity and mortality (Kane et

The risk appears to be greatest with mucin secreting adenocarcinomas of the breast, lung, stomach and colon. However, PTE has also been reported in hepatocellular, prostate, renal cell and choriocarcinomas. Other rare associations are listed below (K. E. Roberts et al., 2003).

> Breast Stomach Lung Liver Prostate Pancreas Bone Undifferentiated carcinoma Ovary Bladder Cervix Colorectal Kidney Mesothelioma Wilms' tumor Esophageal Parotid Melanoma Myxoma Thyroid Trophoblastic Vulva Neurogenic sarcoma

Histological studies of tumor emboli in humans and animals have provided some insights into the fate of pulmonary tumor emboli. Schimdt noted that tumor emboli are usually associated with intravascular platelet-fibrin rich thrombi. As a result, cancer cells become fewer and degenerative in appearance during the organization of these thrombi. The tumor emboli have no tendency to invade the arterial wall (Winterbauer et al., 1968). Necropsy studies and animal model studies suggest that tumor emboli are destroyed or remain latent and are not truly metastases. Soares et al (Soares et al., 1993) studied 222 consecutive autopsies of cancer cases and detected pulmonary hypertensive arteriopathy

Table 11. Primary Tumors associated with Tumor Embolism

al., 1975; Shields & Edwards, 1992).

**37. Etiology** 

**38. Pathology** 

be transferred to intensive care unit. AFE still carries significant morbidity which includes neurological deficit in significant proportions of mothers as well as newborn. Neonatal survival is reported to be at 70%.

*Either* In the absence of any other clear cause

Acute maternal collapse with one or more of the following features:


Excluding women with maternal haemorrhage as the first presenting feature in whom there was no evidence of early coagulopathy or cardiorespiratory compromise

*Or* Women in whom the diagnosis was made at post-mortem examination by finding fetal squames or hair in the lungs

Table 10. UK Obstetric Surveillance System (UKOSS) criteria for defining cases of AFE
