Published in:
01-04-2015 | Original Article
Histopathological and immunohistochemical characteristics of superficial squamous cell carcinoma forming droplet infiltration: indicator of lymph node metastasis of the esophagus
Published in: Esophagus | Issue 2/2015
Login to get accessAbstract
Background
Droplet infiltration (DI) is a tumor infiltration pattern observed in superficial squamous cell carcinoma (SSCC) of the esophagus. Lymph node metastasis (LNM) is related to three reported features of DI (DILFs): longitudinal diameter ≤20 μm (DIsLF); number of constituent cells ≤4 (DInLF); distance from the primary focus ≥200 μm (DIdLF). The aim of this study was to clarify the characteristics of SSCC with high risk of LNM, by analyzing DILF-forming SSCC histopathologically and immunohistochemically.
Methods
Forty-five SSCC invading the muscularis mucosa or submucosa were divided into two groups with and without above-mentioned three DILFs. The Ki-67 labeling index (LI) and the expression of cytokeratin (CK) 13, 14, 17, and 19 were compared in the paired.
Results
The Ki-67 LI was elevated in SSCC with DIsLF and with DInLF (P < 0.001, each), but no significant difference was observed between SSCC with and without DIdLF. The expression of CK13 was decreased in SSCC with DIsLF (P < 0.01) and with DInLF (P < 0.001), but no significant difference was observed between SSCC with and without DIdLF. For CK14, CK17, and CK19, no significant difference was observed between SSCC with and without any DILF.
Conclusions
The results indicated that DIsLF and DInLF are not only LNM predictors, but useful morphological markers reflecting excessive cell proliferation, and that the reduced expression of CK13 is closely associated with DIsLF and DInLF formation at the invasive front. Therefore, the elevation of Ki-67 LI and reduced expression of CK13 suggest higher risk of LNM in esophageal SSCC.