Skip to Main Navigation
Skip to Page Content
  • Skip to Atlas Navigation
  • Spleen, Red Pulp - Hyperplasia, Stromal

    Image of hyperplasia, stromal cell in the spleen from a female F344/N rat in a chronic study
    Spleen, Red pulp - Hyperplasia, Stromal cell in a female F344/N rat from a chronic study. Intersecting, irregular bundles and bands of stromal cells (arrow) infiltrate the splenic red pulp.
    Figure 1 of 4
    Image of hyperplasia, stromal cell in the spleen from a female F344/N rat in a chronic study
    Spleen, Red pulp - Hyperplasia, Stromal cell in a female F344/N rat from a chronic study. Stromal cells (arrows) are spindle to polygonal in shape and have eosinophilic cytoplasm and ovoid nuclei with euchromatic chromatin.
    Figure 2 of 4
    Image of hyperplasia, stromal cell in the spleen from a female F344/N rat in a chronic study
    Spleen, Red pulp - Hyperplasia, Stromal cell in a female F344/N rat from a chronic study. Intersecting, irregular bundles and bands of stromal cells (arrows) infiltrate the splenic red pulp.
    Figure 3 of 4
    Image of hyperplasia, stromal cell in the spleen from a female F344/N rat in a chronic study
    Spleen, Red pulp - Hyperplasia, Stromal cell in a female F344/N rat from a chronic study. Stromal cells (arrows) are spindle to polygonal in shape and have eosinophilic cytoplasm and ovoid nuclei with euchromatic chromatin and a single nucleolus.
    Figure 4 of 4
    next arrow

    comment:

    Stromal cell hyperplasia in the spleen of rodents is rare ( Figure 1image opens in a pop-up window , Figure 2image opens in a pop-up window , Figure 3image opens in a pop-up window , and Figure 4image opens in a pop-up window , arrows). It is typically a focal lesion primarily affecting the red pulp, but there may be infiltration into the periarteriolar lymphatic sheaths and marginal zones. In larger lesions, entrapped white pulp may be atrophied. The proliferating stromal cells are oval to elongated with eosinophilic cytoplasm and oval nuclei. The sinuses may be obliterated or replaced by capillaries, and there may be mature adipocytes within the lesion. It has been reported that, in response to congestion, systemic tumor growth, or treatment with a hematotoxic compound, the stromal cells increase either their contractile properties or their production of extracellular fibers. Thus, there may be increased collagen and expression of smooth muscle actin within the lesion. The exact cell involved in the lesion has not been identified. This lesion should not be confused with neoplasia. With stromal cell hyperplasia, there may be a heterogeneous cell population (e.g., histiocytes and fibroblasts) and a low mitotic index.

    recommendation:

    Whenever stromal cell hyperplasia in the spleen is present, it should be diagnosed and graded.

    references:

    National Toxicology Program. 2002. NTP TR-523. Toxicology and Carcinogenesis Studies of Diisopropylcarbodiimide (CAS No. 693-13-0) in F344/N Rats and B6C3F1 Mice (Dermal Studies). NTP, Research Triangle Park, NC.
    Abstract: http://ntp.niehs.nih.gov/go/16207

    National Toxicology Program. 2007. NTP TR-535. Toxicology and Carcinogenesis Studies of 4-Methylimidazole (CAS No. 822-36-6) in F344/N Rats and B6C3F1 Mice (Feed Studies). NTP, Research Triangle Park, NC.
    Abstract: http://ntp.niehs.nih.gov/go/13651

    Ruehl-Fehlert C, Hartmann E, Rinke M. 2008. Reactive and proliferative changes of splenic reticulum cells of rats investigated with special staining methods and immunohistochemistry. Exp Toxicol Pathol 59:281-290.
    Abstract: http://www.ncbi.nlm.nih.gov/pubmed/18054213

    Suttie AW. 2006. Histopathology of the spleen. Toxicol Pathol 34:466-503.
    Full Text: http://tpx.sagepub.com/content/34/5/466.full.pdf