Related Experiment Video
Updated: Jul 27, 2026
Using Unfixed, Frozen Tissues to Study Natural Mucin Distribution
Published on: September 21, 2012
Acellular mucin in pseudomyxoma peritonei of appendiceal origin: what is adequate sampling for histopathology?
Marwa Al-Azzawi1, Joseph Misdraji2, Marie-Louise F van Velthuysen3
1Department of Surgery, Peritoneal Malignancy Institute, Basingstoke and North Hampshire Hospital, Basingstoke, UK azzawi91@hotmail.com.
Introduction:
Acellular intra-abdominal mucin is associated with a favourable prognosis in pseudomyxoma peritonei. There are no current guidelines on how many blocks are needed to classify the mucin as acellular with confidence.
Methods:
Specimens from cytoreductive surgery for mucinous appendiceal neoplasia, in which acellular mucin was found on initial histopathological examination, were prospectively identified. Additional tissue blocks were then taken to include either all residual visible intra-abdominal mucin or a maximum of 30 blocks. We also sent a questionnaire to pathologists in other centres.
Results:
Twelve patients were identified. In two cases, neoplastic epithelial cells were found on taking additional blocks. The questionnaire results suggested considerable variation in block-taking practice.
Conclusion:
Taking additional tissue identified neoplastic cells in 2 of 12 cases. We recommend that sampling additional material should be considered when only acellular mucin is found on initial histology. Further work to determine the optimum sampling protocol is indicated.
Insights
Sampling additional tissue blocks when acellular mucin is initially found in pseudomyxoma peritonei cases can reveal neoplastic cells. This study suggests current practices vary, highlighting the need for optimized sampling protocols.
Area of Science:
- Gastroenterology
- Surgical Pathology
Background:
- Acellular intra-abdominal mucin correlates with a favorable prognosis in pseudomyxoma peritonei.
- Current guidelines lack specificity regarding the number of tissue blocks required to confidently classify mucin as acellular.
Purpose of the Study:
- To investigate the diagnostic yield of additional tissue sampling in cases of pseudomyxoma peritonei initially showing acellular mucin.
- To assess current pathologist practices in tissue block sampling for acellular mucin.
Main Methods:
- Prospective identification of specimens from cytoreductive surgery for mucinous appendiceal neoplasia with initial acellular mucin findings.
- Collection of additional tissue blocks (up to 30) to encompass residual mucin.
- A survey was distributed to pathologists regarding their block-taking practices.
Main Results:
- Neoplastic epithelial cells were identified in additional blocks in 2 out of 12 (16.7%) evaluated cases.
- Pathologist responses indicated significant variability in tissue block sampling procedures.
- Initial assessment of acellular mucin may not be definitive.
Conclusions:
- Additional tissue sampling is recommended when initial histology reveals only acellular mucin in pseudomyxoma peritonei.
- Further research is necessary to establish optimal sampling protocols for accurate histopathological assessment.
More Related Videos
08:51Murine Appendectomy Model of Chronic Colitis Associated Colorectal Cancer by Precise Localization of Caecal Patch
Published on: August 24, 2019
09:19Culture and Imaging of Ex Vivo Organotypic Pseudomyxoma Peritonei Tumor Slices from Resected Human Tumor Specimens
Published on: December 9, 2022
Related Concept Videos
01:20Histology of the Gastrointestinal (GI) Tract
The mucosa is sometimes called a mucous membrane due to its mucus-secreting features. This membrane is composed of epithelium, which directly interacts with ingested substances, and the lamina propria, a layer...
01:22Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...
01:19Appendicitis