Aggressive Intestinal Symptoms Caused by Metastatic Tumors Originating from Primary Gastric Cancer in Pregnancy: A Case Report

Abstract

Gastric carcinoma is extremely rare in pregnancy and the prognosis for this malignancy tends to be dismal. We herein describe a case of gastric cancer in pregnancy to alert clinicians to this rare possibility. A 29-year-old woman developed abdominal spastic pain and diarrhea during the 26 weeks of gestation and her condition was confusing and hard to recognize. The patient was initially misdiagnosed as enterogastritis and inflammatory intestinal obstruction and was finally confirmed by exploratory laparotomy with intestinal and peritoneum metastases. Because the disease was not detected early enough and progressed rapidly, the pregnancy was terminated by cesarean section at 30 weeks of gestation, and then followed by systemic chemotherapy, but eventually succumbed to the lethal pneumonia. Therefore, it is of great significance to alert clinicians to note this rare possibility and to consider the differential diagnosis of this disease in pregnant women with a long course of gastrointestinal symptoms that cannot be explained by pregnancy alone, and cancer should be suspected and tested with sophisticated diagnostic procedures.

Introduction

Gastric cancer associated with pregnancy is a rare condition, which accounts for less than 5% of all myriad of malignancies that may occur in pregnancy.¹ Due to its rarity and atypical symptoms at the early stage, it represents major diagnostic challenges and often causes adverse maternal and fetal prognosis. Thus, it is significant for obstetricians and surgeons to include this possibility in the differential diagnosis of abdominal discomfort, especially in the presence of persistent nausea, emesis, fatigue, and abdominal pain in pregnancy, where warrant further workup is needed to exclude it. We managed an extremely misleading and complex case in which who was initially diagnosed with gastroenteritis, because she had no particular discomfort from the conception and she had eaten unclean food just before the onset of aggressive gastrointestinal symptoms, which turned out to be poorly differentiated gastric carcinoma with colonic and peritoneal metastases which still remains the most life-threatening type of metastasis. Presentation of this case aims to alarm clinicians about this possibility at any time. Our paper has obtained the written consent of the patient’s immediate family members for publication of this case report.

Case presentation

A 29-year-old pregnant female, gravida 1, para 0, presented with intermittent epigastric spastic pain and nausea for 2 days, but she did not take it seriously as she had eaten some cold and unclean food before symptoms onset. Until she developed diarrhea (10 times per day, watery stool) accompanied by vomiting, she admitted to our Gastroenterology Department. The physician considered her symptoms to be associated with the unclean food and prescribed her omeprazole, clostridium butyricum, and anticholine drugs, the patient was discharged after clinical symptoms were alleviated. One week after discharge, the patient was re-admitted to our Emergency Department with the complaint of stopping exhaust and defecation for 5 days and increased abdominal pain for 2 days, accompanied by severe nausea and vomiting. The physical examination suggested diffuse abdominal tenderness and mild rebound and no mass was touched. While abdominal ultrasonography showed enlarged intestine with gas accumulation and a small amount of peritoneal effusion. She immediately accepted gastrointestinal decompression and anti-infection treatment but her condition did not improve. She was then referred to our Obstetrics Department due to unexplained intestinal obstruction on June 12, 2019. At the time of admission, she was 26 weeks and 4 days of gestation. The fetus was stable and had no contractions after fetal heart monitor and pelvic ultrasound evaluation by Doppler ultrasound.

In her deepened anamnesis, she did not have epigastric pain or black defectation but only mild nausea in the first trimester. She received regular prenatal care and no obvious abnormalities were found involving abdomen or pelvic by ultrasound. She was only diagnosed as pregnancy complicated with vulvovaginal candidiasis without using drugs. Her medical history and family history was unremarkable. After admission, an abdominal tube was established to drain off the ascites to relieve abdominal distention. To figure out the primary disease, we gave her a computed tomography (CT) scan of the abdomen with informed consent. The CT report showed dilatation of the small intestine with accumulation of gas and fluid, but no lesions were found. Lab investigations revealed elevated Creaction protein level (44.2 mg/L) and serum procalcitonin level (0.753 ng/mL), and the patient was suspicious of infection-related intestinal necrosis. After repeat discussion we decided to have an exploratory laparotomy to figure out the primary disease.

An exploration of the abdominal cavity revealed that almost the entire colon was occupied by multiple small masses, and the whole stomach presented “plastic narrow gastritis,” suggesting an unresectable gastric cancer with extensive intraperitoneal metastasis. We ordered conservative treatment to protect the fetus according to the patient’s will. Due to the deterioration in her general condition, pregnancy was interrupted via the cesarean section at 30 weeks and a 1800 g female baby was delivered with a 1^stminute Apgar score of 7 and 5^th minute Apgar score of 10. The patient was then transferred to the general surgery team and performed right hemicolectomy. As the histological examination of biopsy specimens from the stomach and descending colon (Fig. 1) showed poorly differentiated adenocarcinoma with partial signet ring cell carcinoma, the patient was referred to the Beijing Cancer Hospital and received three cycles of chemotherapy treatment. During the chemotherapy sessions, the physical status of the patient did not improve significantly and she finally died of severe pneumonia related to the impaired immune function 6 months after diagnosis. Her baby was discharged after 3 weeks of follow-up in the Neonatal Intensive Care Unit.

Figure 1: Gastric poorly differentiated adenocarcinoma. A Hematoxylin and eosin stain, x20 magnification. B Hematoxylin and eosin stain, ×100 magnification.

Discussion

Gastric cancer still carries a high mortality in developing countries, where diagnosed during pregnancy can be devastating for both the mother and the fetus. Clinical features of early gastric cancer during pregnancy include abdominal discomfort followed by nausea and/or emesis, nonspecific dyspepsia, anemia, and melena, which can be easily presumed to be secondary to normal pregnancy. When tumor spreads to the colorectum or peritoneum, can cause the change of bowel habits, diarrhea, constipation appears alternately, ascites or intestinal obstruction symptoms. However, it is important to note that physicians need to be fully aware of the progression of the disease, as symptoms at a certain stage can occur due to functional and anatomic changes in the gastrointestinal tract during pregnancy, and infection-induced gastroenteritis can be misleading.

Studies have shown that there are estrogen receptors in gastric cancer, especially gastric adenocarcinoma, which means the hormonal milieu during pregnancy may have an impact on the growth and metastasis of tumors.² Given that the treatment outcome mainly determined by the tumor stage and location, early detection and curative resection are the most effective and advocated approaches to improve the prognosis of pregnancy-associated gastric cancers.³ We suggest that young pregnant females should be highly suspected of gastrointestinal malignancies if they suddenly develop severe or aggressive recurrent gastrointestinal discomfort regardless of the predisposing factors.

When a patient’s conditions worsen or relay after expectant or pharmaceutic treatment, it is important to use the most effective diagnostic method for the suspected disease, whether it be a CT scan or magnetic resonance imaging, rather than a poor diagnostic method due to fear of radiation exposure. Serum carcinoembryonic antigen or carbohydrate antigen 19-9 measurements also contribute to prognosis, and their levels are not affected by pregnancy.^4,5 However, in our case, neither abdomen ultrasound nor CT detected small metastatic tumor hidden in the uterus, and invasive procedures such as diagnostic abdominal paracentesis, gastrointestinal endoscopy, and laparotomy should be performed when there are clear indications.⁶ Since we had provided the patient progesterone to inhibit uterine contractions, extensive intraabdominal disease, and iatrogenic operations did not provoke spontaneous preterm contractions.

In pregnant women with advanced stage gastric cancer, the diffuse type is the most common histological diagnosis, accounting for 92.5%–93%, and surgery is not a feasible option.⁷ Several reports suggest that palliative chemotherapy regimen may be considered to treat symptoms and improve survival. If administered after the fetal organo-genesis period (occurring after 2–8 weeks of gestation) does not increase the risk of fetal malformation or cognitive impairment, but may be associated with increased fetal risk of toxicity, stillbirth, and intrauterine growth restriction.^8–10 However, long-term outcome of children prenatally exposed to chemotherapy remains unclear and further follow up of these children is indispensable.

In conclusion, the acute abdomen disease experienced by the patient was caused by gastric cancer, which occurs rarely during pregnancy. It is still the most important and intractable problem to distinguish the physiological reaction of pregnancy from the abnormal symptoms of tumor. Imaging modalities sometimes have limitations, and when clinical symptoms are suspicious, serological tests or even invasive examinations should be used to confirm the diagnosis. More prospective studies are needed to prove whether pregnancy accelerates the progression of gastric cancer and to guide the treatment of cancers during pregnancy.