Case description

A 34-year-old woman, gravida 4, para 3, presented to a tertiary centre at 26 weeks gestation with right-sided abdominal pain and constipation. She had been managed for a pelvic infection 18 months prior to presentation due to both chlamydia and gonococcus and she also volunteered a past history of irritable bowel syndrome. She was a current smoker. An abdominal ultrasound was performed, which showed a complex collection in the right lumbar region of the abdomen. An MRI on the same day demonstrated a retrocaecal loculated collection measuring approximately 61 x 73 x 50mm with surrounding fat stranding, reported to be consistent with appendicitis and a peri-appendiceal complex collection. She had a mildly elevated white cell count (10.8×109/L) and a raised C-reactive protein (CRP) of 150 mg/L.

Surgical consultation was undertaken, and the decision made for laparotomy that night to further evaluate the findings. At the time of the operation, the appendix could not be clearly defined. An abscess at the lateral aspect of the caecal pole was washed out with view to performing an interval appendicectomy postpartum. A drain was inserted, and removed four days postoperatively. Histopathology of the mesoappendix demonstrated acute inflammatory changes and abscess formation. Culture of the purulent fluid drained grew Escherichia coli and mixed anaerobic flora. She recovered well post-operatively and was managed with intravenous ceftriaxone and metronidazole. Her pain improved, and she was discharged home six days post-operatively with oral antibiotics.

The patient re-presented multiple times postoperatively (between 28 to 34 weeks gestation) with purulent discharge and worsening pain in the vicinity of the previous abdominal drain site and in the right flank, despite ongoing oral antibiotics (amoxicillin and clavulanic acid). A further MRI at 29 weeks gestation demonstrated a fluid-filled tract from the right iliac fossa to the right lateral abdominal wall, suspected to be a colo-cutaneous fistula. A percutaneous drain was placed under interventional radiology guidance and remained in situ until after delivery. Due to concerns regarding the fetal implications of ongoing episodes of infection, a maternal-fetal medicine consultation was obtained to assess for any ultrasound evidence of central nervous system changes. No abnormalities were discovered. The patient was discharged home again with twice-weekly outpatient follow-up appointments for clinical review and review of inflammatory markers.

Due to concerns raised by a rising CRP, and the fact that the patient was now at 36 weeks, induction of labour with Prostaglandin gel was planned. She proceeded to an uncomplicated normal vaginal delivery of a well-grown infant (3047g). The baby was well at birth, with Apgar scores of 8 at one minute and 9 at five minutes. The baby was admitted to the neonatal intensive care unit for five days post-delivery due to respiratory distress requiring CPAP, thought to be due to transient tachypnoea of the newborn. The baby was given intravenous penicillin and gentamicin due to concerns for potential sepsis, although all blood cultures remained negative.

One week postpartum, the patient reported ongoing significant pain. CT scan demonstrated a persistent multiloculated retrocaecal collection with a thick enhancing rim extending superiorly to the inferior pole of the right kidney, as well as an abdominal wall collection which had increased in size since previous imaging. The patient was taken to theatre for a laparoscopic appendicectomy, but due to the operative findings of anatomical distortion and severe inflammatory adhesions, this was converted to a laparoscopically assisted right hemi-colectomy. Histopathology subsequently demonstrated a 7cm appendiceal mucinous adenocarcinoma (pT4a pN0), moderately differentiated with foci of lymphatic space invasion. 19 lymph nodes were sampled with no evidence of tumour.

Adjuvant chemotherapy with XELOX (oxaliplatin and capecitabine) was commenced, and at the time of writing, the patient is undergoing her seventh cycle of this regime. Dose reductions of the chemotherapy were required due to nausea, vomiting and diarrhoea. She is planned to receive six months of chemotherapy, with repeat imaging and potential laparoscopic surveillance after completion given her high-risk disease.

Discussion

Tumours of the appendix presenting in pregnancy are rare; there has only been one other case describing mucinous adenocarcinoma of the appendix, and three reports of carcinoid tumours of the appendix diagnosed during pregnancy. In the one other case of mucinous adenocarcinoma of the appendix in pregnancy,¹ this occurred in a 36-year-old woman who was 18 weeks pregnant, with a finding of a 4cm mass following laparoscopic appendicectomy. This patient subsequently decided to terminate the pregnancy and proceeded to complete debulking surgery with right colectomy and intraperitoneal heated chemotherapy. After 10 months of follow-up, the authors described a satisfactory outcome. Three other case reports have been published describing carcinoid tumours of the appendix diagnosed during pregnancy,^{2 3 4} although these have a very different prognosis to adenocarcinomas.

Diagnosis of the tumour in this case was complicated by a preterm pregnancy and difficulties operating in the presence of a gravid uterus, which necessitates consideration of the operative technique and positioning of the mother with regards to compression of the inferior vena cava. Planned interval appendicectomy is a recognised treatment for perforated appendicitis complicated by abscess and may be safer in pregnancy than primary definitive surgery. In this case, the perforation was almost certainly due to the tumour, resulting in tumour stage T4a at the index presentation and mandating adjuvant chemotherapy.

Due to her age and fitness, this patient was a good candidate for adjuvant chemotherapy, although the evidence for this is limited as this is generally extrapolated from large colorectal cancer trials, with poor inclusion of appendiceal mucinous adenocarcinomas. A large retrospective database published in 20165 of more than 11,000 patients with Stage 1–3 adenocarcinomas of the appendix demonstrated a five-year overall survival of 53.6% for mucinous adenocarcinomas of the appendix. There was improved overall survival observed for patients who received systemic chemotherapy (Hazard Ratio 0.79,)⁵ although chemotherapy regimens varied.

Conclusion

Appendiceal tumours are rare, and present additional challenges when arising in pregnancy due to the difficulties in diagnosis and management.

1. Chiverto Y, Cabezas E, Perez-Medina T, Sanfrutos-Llorente L. Infiltrating mucinous appendicular carcinoma during pregnancy. A case report and review of the literature. Journal Obstet Gynaecol. 2015;35(8):856-8.
2. Piątek S, Gajewska M, Panek G, Wielgoś M. Carcionoid of the appendix in pregnant woman – case report and literature review. Neuroendocrinology Letters. 2016;27:535-9.
3. Poiana C, Carsote M, Trifanescu R, et al. Case study of appendiceal carcinoid during pregnancy. J Med Life. 2012;5:325-8.
4. Pitiakoudis M, Kirmanidis M, Tsaroucha A, et al. Carcinoid tumor of the appendix during pregnancy. A rare case and a review of the literature. Journal of BUON. 2008;13:271-5.
5. Asare EA, Compton CC, Hanna NN, et al. The impact of stage, grade, and mucinous histology on the efficacy of systemic chemotherapy in adenocarcinomas of the appendix: Analysis of the National Cancer Data Base. Cancer. 2016;122:213-21.