Multimodality Imaging Evaluation of an Uncommon Entity: Esophageal Heterotopic Pancreas

A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT), fluoroscopic upper gastrointestinal (GI) evaluation, endoscopic ultrasound (EUS), and positron emission tomography (PET) evaluation, revealing the presence of a heterogeneous esophageal mass. In light of imaging findings and clinical workup, the patient was ultimately referred for thorascopic surgery. Surgical findings and histology confirmed the diagnosis of esophageal heterotopic pancreas. 1. Introduction Heterotopic pancreas is defined as histologically proven normal pancreatic tissue that lacks anatomic, vascular, and ductal continuity with the orthotopic pancreas. Other common names for this entity include ectopic, aberrant, or accessory pancreas [1]. Heterotopic pancreas is most commonly discovered incidentally in the abdomen. However, intrathoracic location in association with the esophagus is rare, with only 15 cases reported in the English literature [2]. Here, we report a very rare case of esophageal heterotopic pancreas discovered after extensive radiologic investigation and pathologic correlation. 2. Case Presentation A 25-year-old male with no significant past medical or surgical history presented with 2 weeks of moderate to severe right upper quadrant and epigastric abdominal pain. His pain was occasionally associated with heavy exercise and meals. Physical exam and clinical laboratory findings were unremarkable. Initial radiographic evaluation demonstrated abnormal frontal and lateral chest images (Figures 1(a) and 1(b)). Following the descending aortic shadow inferiorly, a subtle opacity with a rounded contour was identified superior to the gastroesophageal (GE) junction. This was not well appreciated on the lateral view, possibly due to the overlapping shadow of the posterior mediastinum. These radiographic findings were suspicious for a retrocardiac posterior mediastinal mass. Figure 1: (a) Frontal radiograph shows the presence of a hemispheric, retrocardiac opacity superior to the left cardiophrenic sulcus (arrowheads). (b) Lateral radiograph demonstrates a subtle rounded lucency marginating the posterior aspect of the heart (curved arrow). Given the vague right upper quadrant and epigastric symptoms, a right upper quadrant ultrasound (US) was performed. However, the exam was noncontributory. Continued suspicion for a mass prompted further evaluation with computed tomography (CT)