A Case of Cecal Cancer with Lymph Node Metastasis Despite Infiltration Limited to the Mucosa

Abstract

The patient was a 71-year-old female who was examined at a local clinic because of occasional bleeding when she defecated during the previous several months, and she was referred to our hospital for a thorough gastrointestinal (GI) examination. When advanced rectal cancer was detected during an endoscopic examination of the lower GI tract and abdominal CT revealed a mass in the ileocecal area in addition, a proctectomy and simultaneous ileocecal resection were performed. The ileocecal mass was observed to be in the form of a semipedunculated polyp on the cecum, and although routine pathological examination by hematoxylin and eosin (H.E.) staining showed pTis depth of invasion, a diagnosis of local lymph node metastasis was made. The results of a repeat examination by D2-40 immunostaining and additional excision revealed that the deepest part of the mass was limited to within the mucosa, but vascular invasion was observed in the proper mucosal layer and submucosal layer, and the final histopathological diagnosis was pT1a(Ly)-M, ly1. It was concluded that even when based on a routine pathological examination the diagnosis is Tis cancer, T1 cancer is also possible, and in some cases a detailed assessment by D2-40 immunostaining and preparation of a large number of sections is necessary despite appearing to be Tis cancer based on endoscopic excision.