Urinary System

Kidney, Renal Tubule - Hyperplasia, Amphophilic-Vacuolar

Narrative
Comment:
Amphophilic-vacuolar (A-V) hyperplasia is a small proliferative lesion associated with variable amphophilic cytoplasmic staining and intra- and/or extracellular vacuoles (Figure 1). As with atypical tubule hyperplasia, in A-V hyperplasia the proliferating cells are considered to be within the confines of a single renal tubule. If the cells proliferate beyond the confines of a single tubule, the lesion is considered a neoplasm (adenoma or carcinoma). A-V hyperplasia has been postulated to be a familial condition in rats, which may progress to tumors.
Recommendations:
Amphophilic-vacuolar hyperplasia should be diagnosed as "Kidney, Renal tubule - Hyperplasia, Amphophilic-vacuolar" and given a severity grade.
Related Links:
Kidney - Renal Tubule - Atypical Tubule Hyperplasia
Kidney - Renal Tubule - Hyperplasia, Oncocytic
References:

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

Hard GC, Seely JC, Kissling GE, Betz LJ. 2012. Spontaneous occurrence of a distinctive renal tubule phenotype in rat carcinogenicity studies conducted by the National Toxicology Program. Toxicol Pathol 36:388-396.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/18441261

Kudo K, Hoshiya T, Nakazawa T, Saito T, Shimoyama N, Suzuki I, Tamura K, Seely JC. 2012. Spontaneous renal tumors suspected of being familial in Sprague-Dawley rats. J Toxicol Pathol 25:277-280.

Abstract: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3517924/
  • Image of renal tubule hyperplasia, amphophilic-vacuolar in the kidney from a female F344/N rat in a chronic study

    Kidney, Renal tubule - Hyperplasia, Amphophilic-vacuolar in a female F344/N rat from a chronic study. There is a small focus of hyperplastic tubule cells with amphophilic and vacuolated cytoplasm.

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Kidney, Renal tubule - Hyperplasia, Amphophilic-vacuolar in a female F344/N rat from a chronic study. There is a small focus of hyperplastic tubule cells with amphophilic and vacuolated cytoplasm.
Kidney, Renal tubule - Hyperplasia, Amphophilic-vacuolar in a female F344/N rat from a chronic study. There is a small focus of hyperplastic tubule cells with amphophilic and vacuolated cytoplasm.

Authors 

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

Amy Brix, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Reviewers

Kendall S. Frazier, DVM, PhD, DACVP, DABT
Director, Cellular and Molecular Pathology, Safety Assessment
GlaxoSmithKline
King of Prussia, PA

Gordon C. Hard, BSc, BVSc, PhD, DSc, FRCPath, FRCVS, FAToxSci, DACVP
Expert Consultant
Tairua, New Zealand

Susan A. Elmore, MS, DVM, DACVP, DABT, FIATP
Staff Scientist, NTP Pathologist
NTP Pathology Group
National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC