ESOPHAGEAL CANCER ASSOCIATED WITH MULTIPLE CANCEROUS LESIONS - CLINICOPATHOLOGICAL COMPARISONS BETWEEN MULTIPLE PRIMARY AND INTRAMURAL METASTATIC LESIONS

Detailed histopathological examination of serial blocks and subserial sections of the entire resected esophagus in 111 patients who underwen t esophagectomy for esophageal squamous cell carcinoma revealed 38 ass ociated cancerous lesions apart from the main tumors, in 33 patients ( 29.7%). These associated lesions were divided into multiple primary le sions (MPLs; 27 lesions in 23 patients) and intramural metastatic lesi ons (IMLs; 11 lesions in 10 patients). Thirteen and fourteen MPLs were distributed on the proximal and distal sides, respectively, of the ma in tumor with the same mean distance of 2.6 cm. Three and 8 IMLs were located on the proximal and distal sides, respectively, with mean dist ances of 3.4 cm and 4.6 cm. With respect to the histological depth of cancer invasion, MPLs were all confined within the submucosal layer (s uperficial cancer) while IMLs varied from the submucosa to the adventi tia. Histological findings indicate that MPLs may be associated with a possible increased multicentric carcinogenic potential in the non-can cerous epithelium of the esophagus of patients who have had an anteced ent esophageal cancer, and that IMLs are developed by intramural lymph atic spread from the primary esophageal cancer. These results emphasiz e the need for careful attention to the choice of margins during the s urgical resection of the esophagus.