Pancreatic herniation: a large pancreatic mass concealed within the intrathoracic cavity

Background

Pancreatic hiatal herniation is an exceedingly rare entity, with very few cases reported in the literature. Furthermore, pancreatic cancer that has herniated into a hiatal hernia has not previously been reported and warrants physician insight into the possibility of malignancies being concealed in regions with highly complex anatomy. Cancer of unknown primary (CUP) is a challenging diagnostic entity, with much controversy of its optimal management. We aim to highlight awareness of this unreported presentation of pancreatic cancer and to highlight the importance of multimodal imaging to reveal a primary malignancy, particularly when it is concealed within a region of complex anatomy.

Case presentation

An elderly woman in her 70s with a history of coronary artery disease presented to the emergency department following a ground-level fall at home. She reported that she has been feeling particularly weak over the past 2–3 months, and felt as if she had a harder time carrying out her activities of daily living. She notes that walking from her bedroom to the bathroom became progressively more challenging as she would be out of breath and fatigued after activity. The morning of the presentation, she felt particularly weak and as she walked towards her bathroom, she fell forward onto her arms from a standing level. Following this, she reported severe pain to her left upper extremity and the onset of mid-abdominal pain, described as sharp, moderate in severity and constant with no radiation. In the emergency department, her orthostatic vital signs were positive with a change in blood pressure from 143/89 while lying to 113/67 while standing. On further history, she reported a decreased appetite, anorexia and subjective weight loss over the past year. She denied any diarrhoea, steatorrhea, nausea, vomiting, petechiae, purpurae at the time of evaluation and otherwise had no reports. There was no history of tobacco or alcohol use, and she was up to date on all of her cancer screenings. Her physical examination was remarkable for a visible facial laceration and soft tissue injury over the left forearm, and mild tenderness to palpation over the periumbilical region with no radiation to the back.

Investigations

A complete trauma series revealed an oblique fracture through the distal radius and ulna. A CT angiogram of the aorta obtained to rule out an aortic dissection incidentally revealed a large defect in the left diaphragm. Subsequent CT abdomen/pelvis with contrast further revealed a large diaphragmatic hernia with the neck measuring 5.5 cm, containing a rotated stomach and portion of a non-dilated transverse colon. An ill-defined soft tissue lesion (3.9×3.8×3.3 cm) was noted at the neck of the hernia concerning for a necrotic perigastric lymph node (figure 1). Concerningly, numerous hypodense lesions were noted throughout a morphologically cirrhotic liver concerning for metastatic disease. There were no other visible masses noted and a primary cancer site was not identified.

Her complete blood count revealed a stable haemoglobin concentration 12.9 g/dL, with no leukocytosis, but a mild thrombocytopenia of 1 34 000/mm³. Her renal function profile was grossly unremarkable, with a creatinine of 0.83 mg/dL. Her liver profile revealed a mildly elevated aspartate aminotransferase of 64 IU/L (14–33), normal alatine aminotransferase and elevated total bilirubin of 1.8 mg/dL (0.2–1.0) with a direct bilirubin of 1.2 mg/dL (0.0–0.2). She had elevated tumour markers including a carcinoembryonic antigen level of 109 ng/dL (0.0–3.8), CA-125 of 709 U/mL (0–35) and CA19-9 of >10 000 U/mL (0–35).

Differential diagnosis

Given this information and the patient’s history, a decision was made to pursue a CT-guided biopsy of her liver metastases, which revealed a poorly differentiated adenocarcinoma with positive CK7, GATA3 and a weakly positive CDX2 on immunohistochemistry. While immunohistochemistry can typically assist in localisation of a primary site, with the broad pattern of our case, differentials included breast, lung and upper gastrointestinal malignancies. Given our patient’s history of anorexia, subjective weight loss and laboratory findings, a pancreatobiliary malignancy was most concerning.

A magnetic resonance cholangiopancreatography (MRCP) was performed, redemonstrating a large hiatal hernia containing a malrotated stomach in mesenteroaxial volvulus and transverse colon (figure 2). Furthermore, the body of the pancreas laid within the hiatal hernia in the chest, and contained a large 3.9×3.5×4.6 cm heterogeneous mass with dilation of the main pancreatic duct to 7 mm and common bile duct to 10 mm (double duct sign), and encased the coeliac, proximal common hepatic and splenic arteries (figures 2 and 3). Endoscopic ultrasound (EUS) revealed a large, irregular mass within the pancreatic head (figure 4), and subsequent biopsy of the mass confirmed moderately to poorly differentiated pancreatic adenocarcinoma. On retroactive review of prior imaging on the CT scan, the mass previously thought to be a perigastric lymph node was determined to be the underlying pancreatic cancer in a background of highly complex anatomy.

Outcome and follow-up

The patient was counselled on her final diagnosis of pancreatic cancer with hepatic metastases, and a multidisciplinary meeting was conducted between oncology, palliative care and the patient on potential management options, the patient’s goals of care and her prognosis. The patient eventually opted against any chemotherapy or surgical therapy and opted for hospice care. She was successfully discharged to home hospice care.