Urinary System

Urinary Bladder, Urothelium - Cytoplasmic Granules

Narrative
Comment:
Cytoplasmic granules may be observed within the most superficial epithelial “umbrella” cells of the urothelium. They rarely occur in the intermediate or basal cells and typically are deeply eosinophilic. The granules may represent a number of reported constituents, such as degradation products, chemicals/metabolites, or mitochondria. The presence of cytoplasmic granules usually elicits no cell response and has not been associated with either preneoplasia or neoplasia.
Recommendations:
Cytoplasmic granules should be diagnosed and given a severity grade. If treatment related, any unique characteristics of the granules should be described in the narrative report.
References:

Cohen SM. 2002. Comparative pathology of proliferative lesions of the urinary bladder. Toxicol Pathol 30:663-671.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/12512866

Frazier KS, Seely JC, Hard GC, Betton G, Burnett R, Nakatsuji S, Nishikawa A, Durchfeld-Meyer B, Bube A. 2012. Proliferative and non-proliferative lesions in the rat and mouse urinary system. Toxicol Pathol 40:14S-86S.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/22637735

Suzuki S, Arnold LL, Muirhead D, Lu X, Le C, Bjork JA, Wallace KB, Ohnishi T, Kakiuchi-Kiyota S, Pennington KL, Cohen SM. 2008. Inorganic arsenic-induced intramitochondrial granules in mouse urothelium. Toxicol Pathol 36:999-1005.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/19126794
  • Image of cytoplasmic granules in the urinary bladder from a male B6C3F1 mouse in a subchronic study

    Fine, eosinophilic cytoplasmic granules in the superficial cells of the urothelium from a male B6C3F1 mouse in a subchronic study.

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<p>Fine, eosinophilic cytoplasmic granules in the superficial cells of the urothelium from a male B6C3F1 mouse in a subchronic study.</p>

Fine, eosinophilic cytoplasmic granules in the superficial cells of the urothelium from a male B6C3F1 mouse in a subchronic study.
<p>Eosinophilic cytoplasmic granules from a male B6C3F1 mouse in a subchronic study (higher magnification of Figure 1).</p>

Eosinophilic cytoplasmic granules from a male B6C3F1 mouse in a subchronic study (higher magnification of Figure 1).
<p>Cytoplasmic granules-basophilic granules present in the urothelium from a male B6C3F1 mouse in a 28-day study.</p>

Cytoplasmic granules-basophilic granules present in the urothelium from a male B6C3F1 mouse in a 28-day study.

Authors

John Curtis Seely, DVM, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Abraham Nyska,  DVM, Diplomate ECVP, Fellow IATP
Expert in Toxicologic Pathology
Visiting Full Professor of Pathology
Sackler School of Medicine, Tel Aviv University
Timrat Israel

Reviewers

Samuel M Cohen, PHD, MD
Professor
Havlik-Wall Professor of Oncology
Director of Pathology Residency Program
Nebraska Medical Center
Omaha, NE

David E. Malarkey DVM, PhD, DACVP, FIATP
Head, National Toxicology Program Pathology Group
Cellular and Molecular Pathology Branch
Division of the National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC