Pyloric gland type adenoma of the gallbladder with squamoid spindle cell metaplasia

Pathol Res Pract. 1996 Sep;192(9):963-9; discussion 970-1. doi: 10.1016/S0344-0338(96)80081-1.


This study documents a pyloric gland type adenoma of the gallbladder with prominent spindle cell metaplasia arising in a 61 year-old woman. A pedunculated polyp, 1.5 x 1.0 x 1.0 cm, was histologically diagnosed as a tubular adenoma. Most glandular structures showed positivity for a monoclonal antibody M2 (2B5) which indicates a differentiation to pylotic gland type. The spindle cell component displayed no apparent epithelial structures but stained mostly positive for pancytokeratin and cytokeratin (CK) 18, and focally for CK 5 + 6, CKs 7 and 19, whereas CKs 8, 13, 20, and non-epithelial markers could not be demonstrated. This suggests that the spindle cells were immature epithelial cells differentiating towards squamous and/or glandular cells. Even in spindle cell areas, the nuclear atypia was mild, and proliferating cells positive for MIB-1 (Ki-67) antigen were infrequently seen. This unique phenomenon, of which only three cases have been previously reported, is considered to represent benign squamoid spindle cell metaplasia.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / pathology*
  • Epidermis / pathology
  • Epithelium / pathology
  • Female
  • Gallbladder Neoplasms / pathology*
  • Humans
  • Metaplasia / pathology
  • Middle Aged
  • Neoplasms, Squamous Cell / pathology
  • Pylorus / pathology*