Metastasis from prostatic carcinoma causing acute appendicitis: Report of a case

Abstract

INTRODUCTION

Metastasis induced acute appendicitis is extremely rare.

PRESENTATION OF CASE

We present a 72-year-old man who presented with typical signs of acute appendicitis. He underwent appendectomy and was successfully discharged without any complication. Histopathological examination diagnosed the metastasis to appendix from prostatic cancer.

DISCUSSION

Cancers of the appendix are rare and usually diagnosed incidentally in approximately 1% of all appendectomies. The rate of perforation was found to be higher in metastasis induced acute appendicitis in comparison with simple acute appendicitis in the literature. Tumors other than primary appendix tumors when present in the appendix are easily recognized as metastatic, requiring immunohistochemical studies.

CONCLUSION

Metastasis induced acute appendicitis should be considered as part of the differential diagnosis when a oncologic patient presents with signs of acute appendicitis.

1. Introduction

The most common disease of the appendix is acute appendicitis, which usually occurs due to the obstruction of appendix lumen with a fecalith. However metastatic cancer induced acute appendicitis is uncommon. With respect to the English literature only four cases of appendicular metastasis from a prostatic carcinoma has been reported up to date.^1–4 In the present report, we described a case of metastasis to the appendix from prostatic carcinoma with typical signs of acute appendicitis.

2. Presentation of case

A 72-year-old male patient was admitted to the emergency department (ED) with complaints of right lower quadrant (RLQ) pain, nausea and vomiting for 12 h. Physical exam was notable all quadrants tenderness to palpation, with rebound and guarding. Vital signs were within normal limits. Laboratory results revealed a white blood count of 6900/mm³(normal range: 4400–11,300/mm³) and a hematocrit concentration of 29% (normal range: 40–52%). His medical history indicated that he was diagnosed with adenocarcinoma of the prostate and followed by oncology department for 3 years. Oncological consultation revealed that he was administered with a chemotherapy treatment protocol for multipl bone metastasis and he had been partial response. The patient has not been receiving any active treatment for his prostatic cancer at the time of presentation. Contrast-enhanced abdominal computed tomography (CT) was performed in the ED showing free fluid in pelvis and a dilated appendix with thickened wall suggestive of acute appendicitis (Fig. 1). There was no evidence of intraperitoneal metastasis in CT scan. In surgical exploration a firmly swollen gangrenous appendix and a minor perforation was detected and appendectomy was performed. In surgery there was no peritoneal metastasis or evidence of metastasis on appendix.

Fig. 1.

A CT scan showed a thickened and distended appendiceal tip, and infiltration of soft-tissue in ileocecal region suggestive of acute appendicitis.

Histopathological examination showed multiple foci of adenocarcinoma metastasis in appendix mucosa and serosa. Immunohistochemical staining revealed that, the tumor cells expressed prostatic specific antigen (PSA) strongly, but showed negative reactivity for chromogranin A, synaptophysin, CK 7 and for CK 20 (Figs. 2–4). These findings confirmed the prostastic origin of the tumor. The patient was discharged with an uneventful recovery and referred to oncology department to resume his treatment for his prostate cancer.

Fig. 2.

Adenocarcinoma involving the serosa of appendix (H&E, 40×).

Fig. 3.

Strong PSA immunopositivity of the tumor and lymphovascular invasion (PSA immunostain, 40×).

Fig. 4.

Carcinoma infiltrating the obliterated appendix mucosa (H&E, 40×).

3. Discussion

Metastasis induced acute appendicitis is an uncommon clinical entity. The review of the English literature documantated metastasis to appendix from carcinomas of breast, lung, pancreas, stomach, ovary, liver and kidney.^1,5,6 It has been established that metastatic cancers of the appendix do not represent with any specific symptoms or signs.⁶ The obstruction of the appendiceal lumen due to metastatic spread as in our case was described in majority of the reported cases and this was accused to be the mechanism for acute appendicitis.^5,6 And also it has been reported that the rate of perforation was found to be 71% in metastasis induced acute appendicitis cases, while it was 17–39% for simple acute appendicitis.^2,7 This high rate of perforation may be explained with the local effect of the tumor on the ability of the appendix to limit the inflammation, obstruction of the lumen, or the general immunosuppressive condition of cancer patients.

Appendix cancers account for approximately 0.4% of gastrointestinal tumors and is usually diagnosed incidentally in approximately 1% of all appendectomies.^8,9 Carcinoids are the most common accounting for approximately 66%, with cystadenocarcinoma accounting for 20% and adenocarcinoma accounting for 10%.⁸ The remaining neoplasms are adenocarcinoid, signet ring, lymphoma, ganglioneuroma, and pheochromocytoma.

Carcinoid tumors and adenocarcinomas with typical histologic features and specific tumor markers can be easily detected in appendix. However, rather rarely further investigations may be required to determinate the type of tumor as in the presented case. Strong immunoreactivity for PSA suggested the diagnosis of metastatic prostatic adenocarcinoma in our case. Negativity for chromogranin A, synaptophysin, NSE, and S-100 protein excluded the other possible adenocarcinoma and carcinoid tumors.

In previous reports, the interval between the presentation of the cancer and the presentation of appendicitis ranged from 1 month to 5 years.² This interval was 3 years for our patient. With the improved survival in oncological patients, metastases to the appendix may be manifestated more often in future. Although these patients usually have poor prognosis, acute appendicitis due to metastatic spread should be treated in the same rationale as acute appendicitis of any other etiology.¹

4. Conclusion

Although metastasis induced acute appendicitis is rare in clinical practice, it should be considered as part of the differential diagnosis when a oncologic patient presents with symptoms of acute appendicitis.

Conflict of interest

The authors declare no conflict of interest.

Funding

None.

Ethical approval

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Author contributions

Sefa Ozyazici, Faruk Karateke, and Pelin Demirturk contributed in study design. Koray Das and Ebru Menekse contributed in data collection. Faruk Karateke and Mehmet Ozdogan wrote the paper.