Pancreatic Metastases of Rectal Cancer-Case Report and Literature Review

Resection of rectal metastasis after previous radical surgery for pancreatic cancer: Case report and literature review

RATIONALE

Pancreatic ductal adenocarcinoma (PDAC) is the main type of pancreatic cancer with a poor prognosis. Rectal metastasis after radical resection of PDAC is comparatively rare, and the understanding of such cases is currently not unified. This study presents the entire process of diagnosis and treatment of a patient with PDAC metastasized to the rectal. We propose the viewpoint of exploring potential biomarkers or establishing effective predictive models to assist in the clinical decision-making of such cases.

PATIENT CONCERNS

We present the case of a 71-year-old man with slight abdominal distension and dull pain. He underwent surgical treatment for a malignant tumor of the pancreatic body, which was discovered through computed tomography and magnetic resonance imaging examinations. Nine months after the pancreatectomy, a rectal mass was identified by digital rectal examination and diagnosed as a malignant lesion through a puncture biopsy. After a multidisciplinary joint consultation, the patient underwent radical surgery. It was later confirmed as rectal adenocarcinoma based on postoperative pathological results.

DIAGNOSIS

The pathological result after pancreatic surgery was PDAC, which had invaded the peripheral nerves and abdominal arteries. A diagnosis of rectal metastasis was determined ultimately by combining with the medical history and immunohistochemical staining results.

INTERVENTIONS AND OUTCOMES

Treatment of the PDAC included laparoscopic resection of the body and tail of the pancreas combined with splenectomy, and postoperative systemic chemotherapy. In addition, treatment of the rectal metastasis included laparoscopic radical resection and postoperative systemic chemotherapy. The patient's current living condition was good.

LESSONS

As a rare metastatic site of PDAC, rectal metastasis should be avoided because of misdiagnosis and missed diagnosis. Surgical resection is still an effective treatment strategy for localized pancreatic tumors and isolated metastases. Furthermore, the mining of potential biomarkers or the establishment of predictive models for pancreatic cancer and its metastases may contribute to better clinical decision-making in the future.

Literature review of imaging, pathological diagnosis, and outcomes of metachronous lung and pancreatic metastasis of cecal cancer

Background

Pancreatic metastasis from colorectal cancer is extremely rare. Here, we report a case of colorectal cancer with lung and pancreatic metastasis and analyze the histopathology, immunohistochemistry, and next-generation sequencing (NGS) to generate a differential diagnosis and treatment of metastatic colon cancer.

Case presentation

AC1

A 78-year-old man was admitted because of a recently elevated carcinoembryonic antigen. This patient had undergone laparoscopic right hemicolectomy for cecal cancer IIA (T3N0M0) 5 years before admission, and thoracoscopic left upper lung wedge resection for primary colon cancer lung metastasis 2 years before admission. At that time, the patient was thought to have pancreatic metastasis from colon cancer. He underwent laparoscopic distal pancreatectomy (combined with splenectomy). Postoperative pathology revealed colon cancer metastasis. We performed NGS on tumor samples at three loci and found colon cancer's most common oncogenic driver genes (KRAS, APC, and TP53). One month after surgery, the patient was given capecitabine for six cycles of chemotherapy. At present, no high adverse reactions have been reported.

Discussion

For patients with pancreatic space-occupying, such as a previous history of colorectal cancer, and recent carcinoembryonic antigen elevation, we should highly suspect pancreatic metastatic colorectal cancer. NGS is an essential auxiliary for identifying metastatic tumors. Surgery combined with postoperative chemotherapy is an effective treatment.