Abstract | November 8, 2021
Rare Case of Mixed Adenoneuroendocrine Carcinoma in a 73 Year Old Male with Dysphagia
Learning Objectives
- Identify an incredibly rare type of gastrointestinal tumor manifesting in the distal esophagus in patients with a long history of smoking and new complaints of dysphagia.
- Predict patient outcomes after aggressive treatment of the tumor, including the risk of developing severe gastroparesis, malnutrition, and progressively worsening weight loss.
Introduction: Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor of the gastrointestinal tract, and can appear anywhere from the esophagus to the colon or appendix. The pathogenesis of MANEC is unpredictable and it’s prognosis uncertain. Despite the lack of standardized treatments, surgical resection and aggressive multimodal cancer therapy is often recommended.
Case Presentation: A 73 year old male with a 50 pack year smoking history presented to clinic with stable dysphagia, inability to swallow solid foods, and 20 pound weight loss for two months. Vomiting the undigested food would relieve the sensation of obstruction in his midepigastrum. Physical exam was unremarkable. Initial differential diagnoses included dysphagia, gastroesophageal reflux disease, and unintentional weight loss. Esophagogastroduodenoscopy (EGD) showed nodular duodenitis at the duodenal bulb including nodular, friable, and ulcerated areas from the gastroesophageal junction (GEJ) up to 35 cm from the bite block. The upper esophagus was unremarkable. Pathology of the biopsies revealed mixed moderate to poorly differentiated adenocarcinoma that stained positively for cytokeratin AE1/AE3, CDX2, and cytokeratin 7, and high-grade neuroendocrine carcinoma that was strongly positive for CD56.
Final Diagnosis: Mixed adenoneuroendocrine carcinoma (MANEC)
Management and Outcome: The patient received neoadjuvant taxane-based chemotherapy and radiation followed by successful distal esophagectomy with reanastomosis to the GEJ. PET scan was negative for metastasis and paraesophageal lymphadenopathy. More than a year after treatment he no longer had dysphagia, but had persistent nausea, loss of appetite, and lost 45 pounds over the last few months. His CMP and CBC labs were unremarkable. Barium swallow revealed severe gastroparesis with narrowing of the gastric lumen at the diaphragm level. Repeat EGDs showed no signs of cancer recurrence. However, long areas of friability, blanching, and narrowing of the gastric antrum and body was present. Biopsies were unremarkable with no signs of intraepithelial lymphocytosis. A percutaneous endoscopic gastrostomy (PEG) tube was placed and he was admitted to a rehabilitation facility. Abdominal cellulitis developed around the tube site and he was sent to the hospital for evaluation and successful replacement of his PEG tube for a jejunostomy tube. However, his hospital course was complicated by sepsis, pneumonia, and ascites. Despite proper management, the patient did not survive the full course of his admission.
