Respiratory System

Lung - Mineral

Narrative

Comment:

Mineral (calcification) is seen as deposits of granular, clumped, laminated, angular, or linear basophilic material that can be intracellular or extracellular (Figure 1, Figure 2, Figure 3, and Figure 4). Metastatic calcification results from hypercalcemia related to increased parathyroid hormone, vitamin D-related disorders, or renal failure resulting in secondary hyperparathyroidism. Dystrophic mineral occurs in areas of necrosis (regardless of derangements of calcium metabolism); it is found within the necrotic tissue and is not generally considered to be interstitial. Metastatic mineral in the alveolar interstitium (alveolar septa) in aged rats is often secondary to renal failure caused by chronic progressive nephropathy.

Recommendations:

Lung - Mineral should be diagnosed when it is considered to be primary and not secondary to necrosis (i.e., metastatic mineralization). A site modifier (e.g., interstitium, blood vessel) should be included in the diagnosis to indicate the location of the mineral. The term "mineral" is preferred over "mineralization." When diagnosed, it should be assigned a severity grade. Associated lesions, such as inflammation, should be diagnosed separately. Mineral secondary to necrosis (dystrophic mineralization) should be diagnosed only when, in the pathologist’s opinion, it is severe enough to warrant a separate diagnosis. The pathogenesis of any treatment-related mineral that is diagnosed should be discussed in the pathology narrative.

References:

Boorman GA, Eustis SL. 1990. Lung. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, CA, 339-367.

Kumar V, Abbas AK, Fausto N. 2005. Robbins and Cotran Pathologic Basis of Disease, 7th ed. Elsevier Saunders, Philadelphia, 41-42.

Renne, R, Brix A, Harkema J, Herbert R, Kittle B, Lewis D, March T, Nagano K, Pino M, Rittinghausen S, Rosenbruch M, Tellier P, Wohrmann T. 2009. Proliferative and nonproliferative lesions of the rat and mouse respiratory tract. Toxicol Pathol 37(suppl):5S-73S.

Abstract: https://www.ncbi.nlm.nih.gov/pubmed/20032296

All Images

Lung, Interstitium - Mineral in a male F344/N rat from a chronic study. Deeply basophilic material is present within the expanded alveolar septa.

Lung, Interstitium - Mineral in a male F344/N rat from a chronic study. Basophilic mineral is present within cells and lining the alveolar septae.

Lung, Interstitium - Mineral in a male F344/N rat from a chronic study. Many of the fragmented alveolar septae contain basophilic material.

Lung, Interstitium - Mineral in a male F344/N rat from a chronic study (higher magnification of Figure 3). The mineral has been deposited primarily along basement membranes.

Authors and Reviewers

Authors

Mark F. Cesta, DVM, PhD, DACVP
Staff Scientist/NTP Pathologist
NTP Pathology Group
National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC

Darlene Dixon, DVM, PhD, DACVP
Group Leader
Molecular Pathogenesis Group
National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC

Ronald A. Herbert, DVM, PhD
Group Leader/NTP Pathologist
Pathology Support Group
National Toxicology Program
National Institute of Environmental Health Sciences
Research Triangle Park, NC

Lauren M. Staska, DVM, PhD, DACVP
Senior Pathologist
WIL Research
Hillsborough, NC

Reviewers

Gary A. Boorman, DVM, PhD, DACVP, DABT, DACLAM
Pathologist
Covance Laboratories, Inc.
Chantilly, VA

Robert C. Sills, DVM, PhD, FIATP
Chief, Cellular and Molecular Pathology Branch
National Toxicology Program
National Institute of Environmental Health Sciences, Research Triangle Park, NC