Clinicopathological characterization of ten patients with primary malignant melanoma of the esophagus and literature review

Abstract

Background: Primary malignant melanoma of the esophagus (PMME) is a rare malignant disease and has not been well characterized in terms of clinicopathology and survival.

Aim: To investigate the clinical features and survival factors in Chinese patients with PMME.

Methods: The clinicopathological findings of ten cases with PMME treated at Henan Provincial People's Hospital were summarized. Moreover, the English- and Chinese-language literature that focused on Chinese patients with PMME from 1980 to September 2021 was reviewed and analyzed. Univariate and multivariate analyses were employed to investigate the clinicopathologic factors that might be associated with survival.

Results: A total of 290 Chinese patients with PMME, including ten from our hospital and 280 from the literature were enrolled in the present study. Only about half of the patients (55.8%) were accurately diagnosed before surgery. Additionally, 91.1% of the patients received esophagectomy, and 88 patients (36.5%) received adjuvant therapy after surgery. The frequency of lymph node metastasis (LNM) was 51.2% (107/209), and LNM had a positive rate of 45.3% even when the tumor was confined to the submucosal layer. The risk of LNM increased significantly with the pT stage [P < 0.001, odds ratio (OR): 2.47, 95% confidence interval (CI): 1.72-3.56] and larger tumor size (P = 0.006, OR: 1.21, 95%CI: 1.05-1.38). The median overall survival (OS) was 11.0 mo (range: 1-204 mo). The multivariate Cox analysis showed both the pT stage [P = 0.005, hazard ratio (HR): 1.70, 95%CI: 1.17-2.47] and LNM (P = 0.009, HR: 1.78, 95%CI: 1.15-2.74) were independent prognostic factors for OS. The median disease-free survival (DFS) was 5.3 mo (range: 0.8-114.1 mo). The multivariate analysis indicated that only the advanced pT stage (P = 0.02, HR: 1.93, 95%CI: 1.09-3.42) was a significant independent indicator of poor RFS in patients with PMME.

Conclusion: The correct diagnosis of PMME before surgery is low, and physicians should pay more attention to avoid a misdiagnosis or missed diagnosis. Extended lymph node dissection should be emphasized in surgery for PMME even though the tumor is confined to the submucosal layer. Both the LNM and pT stage are independent prognosis factors for OS, and the pT stage is the prognosis factor for DFS in patients with PMME.

Keywords: Clinicopathological characteristics; Primary malignant melanoma of the esophagus; Recurrence; Survival; Treatment.

Figure 1

Imaging and microphotograph of primary malignant melanoma of the esophagus. A: Barium swallow examination showed an irregular filling defect on the lower third of the esophagus, causing mucosa destruction; B: Computed tomography showed an eccentric thickening in the lower third of the esophagus wall, with enhancement; C and D: Esophagoscopy revealed a nonpigmented polypoid tumor with hyperemia and erosion in the lower esophagus, and black lesion scattered on the wall of esophagus; E: Hematoxylin-eosin staining identified malignant melanoma cells in the lamina propria of the esophagus (× 100); F: Immunohistochemical staining with HMB45 (human melanoma black 45) antibody revealed positive tumor cells (× 100).

Figure 2

Correlation of tumor size with gender and tumor location. A: Gender; B: Tumor location.

Figure 3

Site of metastasis in the study cohort. ¹Distant lymph nodes including those in the enterocoelia, neck, mediastinum, and axilla.

Figure 4

Survival of patients with primary malignant melanoma of the esophagus. A: Overall survival; B: Disease-free survival.

Figure 5

Kaplan-Meier curves for patients with primary malignant melanoma of the esophagus. A and B: Comparison between the cases with pT1a, pT1b, and pT2, 3, and 4. Patients at pT1a showed a much better overall survival (OS) and disease-free survival (DFS) than those at pT1b or pT2, 3, and 4. No significant difference was observed between groups at pT1b and pT2, 3, and 4 for OS or DFS; C and D: Comparison between the cases with (+) and without (-) lymph node metastasis (LNM). Patients with LNM (+) showed a lower OS than those with LNM (-); for DFS, the difference was only marginal (P = 0.07); E and F: Comparison between the cases with pTNM I, II, and III/IV. Patients at pTNM I showed a much better OS and DFS than those at II and III-IV. No significant difference was noted between groups at pTNM II and III-IV for OS or DFS; G and H: Comparison between the cases with superficial, polypoid, and other gross classifications. Groups with superficial subtype showed a better OS and DFS than those with other subtypes. No significant difference was noted between groups with polypoid and other subtypes for OS or DFS.