Clinical Outcome of primary malignant melanoma of the esophagus：a single-center experience
Authors: Li Xiaoying , Dai Shuang , Liu Ting , Li Ruizhen , Zhang Pei , zhou Lin , Cao Dan 
Published: August 2023

Abstract
Purpose
Primary melanoma of the esophagus (PMME) is a highly uncommon disease. In this retrospective study, we analyzed the pathogenesis, pathology, treatment outcomes, prognosis, and radiologic findings of PMME. The aim of this study is to characterize the clinical features of PMME and provide a comprehensive view of the immunotherapy treatment outcomes, with the goal of further understanding the disease
Materials and methods
We retrospectively searched our hospital from 2009 to 2023 revealed 14 patients with pathologically confirmed PMME, whose clinical features contain immunohistochemical results and image finding were available for review. Medical records were reviewed for treatment efficacy and clinical manifestations.
Results
14 patients with pathologically confirmed PMME were included, 8 patients died a mean of 8 months afterward irrespective of therapeutic modalities, and 3 was alive more than 1 years, while 5 were lost to follow-up. The most common symptom was dysphagia (92.8%,13/14), Before surgery 11 patients underwent contrast material–enhanced chest computed tomographic (CT) scans, 1 only underwent barium esophagogram, and one underwent both CT and barium esophagogram. One patient underwent preoperative PET-CT, one patient received postoperative PET-CT. Chest CT or esophagography/gastroscope which showed located in the middle (n = 8), distal (n = 5), or proximal (n = 1). The median age of patients was 57years (range: 45–77 years), and 85.7% (12/14) of patients were male. 12 patients underwent esophagogastrostomy and 7 (58.3%) of them were found with lymph node metastasis. The routine histology using immunohistochemical staining exhibiting strong reactivity for S-100, and HMB-45 proteins and PCK negative. One patient presented with lung metastases at the time of esophageal surgery, while the remaining patients not had extra-esophagus metastases before surgery. Postoperative pathology revealed tumor diameter ranging from 2-9cm. Adjuvant chemotherapy was performed in 9 patients, and 2 received extra postoperative adjuvant radiotherapy ,5 plus immunotherapy. One patient only received postoperative radiotherapy. Overall survival (OS) in all patient who received surgery (9 of 12) was 7.4 months, despite received adjuvant therapy, most patients (6/9) relapse shortly after surgery and median disease-free time (DFS) 6.1 months. Surprisingly, a patient(case 13) with lymph node metastasis survived more than 2 years after receiving adjuvant immunotherapy(adjuvant anti-PD-1 immunotherapy: Pembrolizumab) besides 5 of 9 received additional immunotherapy are more inclined to have a favorable prognosis.
Conclusion
Primary malignant melanoma of the esophagus is a very rare in this localization. Preoperative radiologically finding and endoscopic biopsy difficult to distinguish from other esophageal malignancies. PMME inclined to with lymph node metastasis despite earlier T stage. The prognosis is dismal for rapid progression despite resection. Traditional adjuvant therapy seems not appear to confer a survival benefit, but adjuvant immunotherapy may improve efficacy after patients received chemoradiation, which warrant for future studies.