[671] Superficial (pT1b) Basaloid Squamous Cell Carcinoma of the Esophagus: Its Clinicopathologic Findings.

Koji Nagata, Michio Shimizu. Saitama Medical University, International Medical Center, Hidaka, Japan

Background: Basaloid squamous cell carcinoma of the esophagus (BSCCE) is a rare distinct variant of esophageal cancer. It is known to be made up of several kinds of tissue components, of which the ductal differentiation (DD) component has the lowest frequency. Recently, some cases of BSCCE with ductal, myoepithelial, and adenoid cystic features type have been reported, and it has been recommended to distinguish it from adenoid cystic carcinoma of the esophagus (ACCE). All of these reports are of advanced cases, and the early phase this tumor is not yet well known. We present three cases of this rare type tumor of the superficial case.
Design: Case 1 is a 71-year-old man who was admitted for an esophageal tumor detected during a routine medical examination. The tumor was located in the lower intrathoracic esophagus, and an esophagectomy was performed. Case 2 is a 56-year-old man who was admitted for hematemesis after alcohol consumption. The tumor was located 31 to 35 cm from the incisor, and an esophagectomy was performed. Case 3 is a 63-year-old man who was admitted for sense of incongruity of the pharynx. The tumor was located 26cm from the incisor, and an endoscopic mucosal dissection (ESD) was performed.
All the lesions were cut in a by 4mm (esophagectomy)/2mm (ESD) width, and histological and immunohistochemical examination was performed.
Results: Grossly, two cases were of a slightly depressed type and a flat type. The depths of all the cases were pT1b. One esophagectomy case was pN2 and the other was pN0. Histologically, all the cases showed the squamous cell carcinoma component in the epithelium, and DD component in the epithelium to submucosa. The DD component consisted of an outer layer and an inner layer of epithelium.
Immunohistochemically, the squamous cell carcinoma component was positive for CK5. In the DD component, the outer layer of epithelium was positive for CK5 and p63 overexpression. Inner epithelium was positive for CK7, human gastric mucin (HGM) and MUC5AC, and was negative for SMA, MUC2 and MUC6. The CK14 positive cells were stained in the epithelial basal to parabasal layers, and in the DD component, positive cells appeared in the inner layer and both of the outer layers. Case 2 showed some NSE/NCAM positive tumor cells, but were negative for chromogranin A and synaptophysin.
Conclusions: BSCCE is an extremely rare tumor of the esophagus and may show the DD suggesting involvement of the basal to parabasal layeres of the squamous epithelium. Cases of BSCCE with NCAM positivity need to be distinguished from small cell carcinoma.
Category: Gastrointestinal

Monday, February 28, 2011 1:00 PM

Poster Session II # 95, Monday Afternoon


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