Advanced lung cancer presenting with a generalized seizure in pregnancy

Abstract

This case describes the initial presentation of lung cancer as a generalized seizure in a woman at 31 weeks gestation. Histologic examination revealed evidence of placental metastases without evidence of fetal involvement. A 34-year-old primigravida was admitted as an emergency to the Labour Suite after a generalized self-limiting seizure at 31/40 gestation. On admission she was drowsy, her blood pressure was 116/68 and catheter urine tested positive for protein (1 +). On examination there was epigastric and right upper quadrant tenderness. Lung auscultation revealed left-sided basal crepitations and there were three beats of clonus and a positive Babinski reflex in the left lower limb. Cardiotocograph was normal and there was no significant edema. Blood tests revealed normochromic normocytic anemia (Hb 10.0), mildly elevated liver enzymes (gGT 83, ALT 55) and a CRP of 34. Platelets, white cell count, urate, urea and electrolytes, random glucose and remaining parameters of liver function were normal. Although there were some unusual features, eclampsia was considered to be the most likely diagnosis. Treatment with magnesium sulfate was commenced according to protocol on the high dependency area of the Labor Suite and 16 mg of dexamethasone was given intramuscularly. Six hours after admission the patient underwent a cesarean section under regional anesthesia. A male infant was delivered in good condition (cord gases normal; birth weight 2.01 kg). Postoperatively the patient remained normotensive and aproteinuric. However, the oxygen saturation was only 80% on room air and there was extensive left-sided bronchial breathing on auscultation. A portable chest X-ray revealed shadowing over the left mid-zone, and the diagnosis of pneumonia was considered. A departmental chest X-ray on day 2 demonstrated a left-sided pleural effusion. Cytological examination of a pleural aspirate revealed adenocarcinoma cells. A CT brain/thorax/abdomen was arranged. This revealed multiple brain metastases with evidence of raised intracranial pressure and a mid-line shift, a left-sided bronchial mass and multiple liver metastases. At bronchoscopy there was evidence of a large malignant looking bronchial mass and biopsies were obtained. Histology revealed an invasive poorly differentiated adenocarcinoma. Immunohistochemistry indicated primary lung cancer. The placental histology revealed microscopic metastatic disease on two separate placental blocks prepared for histology. Subsequently the patient received palliative whole brain radiotherapy and chemotherapy, but the tumor did not respond. The baby made good progress and was discharged. Subsequent follow up to this date has shown no evidence of metastatic disease in the baby. A search of the relevant literature revealed no other case in which the initial presentation of lung cancer in pregnancy was as a generalized seizure. Malignant disease is uncommon in pregnancy and it is estimated to occur in 1 in 1000 to 1 in 1500 of pregnancies (1). Metastasis of a malignancy to the feto-placental unit occur much less frequently and in a review published by Walker et al. in 2001 only 68 cases have been recorded (1). There have been only eight reported cases of maternal pulmonary carcinoma metastatic to the placenta (1). The cancers most commonly occurring in pregnant women are cervical and breast cancer each making up approximately a third of the total of diagnosed cancers (2, 3). These two cancers rarely metastasize to the products of conception and in a 1989 review only seven cases of breast cancer and one case of cervical cancer metastasizing to the products of conception were identified (2). Hemopoietic malignancies account for 25% and melanoma for only 8% of cancers diagnosed in pregnant women (3). Metastasis involvement of the fetus is very rare and Read et al. concluded that it occurs in 27% of reported cases of metastases to the products of conception. Eighty-three per cent of these cases were either malignant melanomas or hemopoietic malignancies (3). Dildy et al. found that 44% of all cases of maternal malignancy involving the products of conception involved the fetus and malignant melanoma accounted for 58% of these cases (2). Lung cancer incidence in young women is increasing due to rising uptake of cigarette smoking at an increasingly young age (4–6). This suggests that lung cancer diagnosed in pregnancy is set to increase (4–6). However, in this case there was no maternal smoking history and it should be considered that adenocarcinoma of the lung is the predominant histologic type in non-smokers. A diagnosis of cancer in pregnancy is often delayed. A pulmonary adenocarcinoma is often slow growing and can present with non-specific symptoms which can be mistaken for infectious diseases. There is often a reluctance to perform radiological imaging in a pregnant woman to investigate a persistent cough and this may delay the diagnosis. An adenocarcinoma of the lung metastasizing to the fetus has been reported. The baby developed metastatic scalp lesions at the age of 2 months. The placenta was not histologically examined in this case (1). The authors were thus unable to comment on whether location of the tumor within the placenta had any bearing on the location of tumor in the baby. The issue of the site of placental metastasis influencing metastatic spread to the fetus remains unresolved due to the lack of reported cases in the literature. It is important to perform both macroscopic and microscopic examination of the placenta in all cases of maternal malignancy. If a tumor is present this necessitates pediatric follow-up. However, due to the small number of cases reported it is very difficult to accurately predict the course of the disease, if any, to the fetus. As metastases to products of conception are such rare events this is not amenable to further analysis (3). Pregnancy has not been shown to alter the biological behavior of lung cancer (5). However, looking at the reported cases in the literature, lung cancer diagnosed during pregnancy tends to be an aggressive and usually fatal disease (6). As previously mentioned, this may be attributable to the delay in diagnosis. Widespread tumor deposits at the time of diagnosis of cancer in pregnancy pose many dilemmas for the patient, relatives and staff. This lady sadly survived for only 4 months after the birth of her son.