title: Carcinoma cuniculatum of the esophagus.
abstract: OBJECTIVE
  Extremely well-differentiated squamous cell carcinoma with the features of so-called carcinoma cuniculatum (CC) is a rare neoplasm. We describe the clinicopathologic findings of the first 2 cases of CC of the esophagus.
  
  
  RESULTS
  Two elderly men presented with symptoms and clinical signs of esophageal malignancy. Repeated endoscopic biopsies of their esophageal tumors were inconclusive. Resection revealed CC of the esophagogastric junction in both cases. The tumors extended into the adventitia but no lymph node metastases were present. In situ hybridization for human papillomavirus HPV subtypes was negative.
  
  
  CONCLUSIONS
  Carcinoma cuniculatum is reported for the first time in the esophagus. The diagnosis of this tumor variant is difficult by means of cytological examination or by endoscopic biopsies alone. Carcinoma cuniculatum in this location shows biologic features similar to verrucous carcinoma (deep penetration, no lymph nodes metastases, and location at one end of the esophagus). No evidence of human papillomavirus could be demonstrated.
authors.affiliation: Department of Pathology, Mayo Clinic Scottsdale, Scottsdale, AZ 85259, USA. depetris.giovanni@mayo.edu
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Petris
authors.forename: Matthew
authors.initials: M
authors.lastname: Lewin
authors.forename: Toru
authors.initials: T
authors.lastname: Shoji
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018289:Carcinoma, Verrucous / Q000175:diagnosis; D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal; D004938:Esophageal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D004943:Esophagogastric Junction / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010212:Papilloma / Q000175:diagnosis; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification
chemical_list: D014408:Biomarkers, Tumor