Thyroid Gland - Ectopic Tissue

Thyroid Gland - Ectopic tissue, Thymus in a female F344/N rat from a subchronic study. Well-formed thymic tissue is present adjacent to the thyroid gland.
Figure 1 of 2
comment:
Ectopic thymic tissue is a congenital change with the extrathymic tissue located either adjacent to ( Figure 1

recommendation:
Ectopic tissue in the thyroid gland should be diagnosed whenever present, but a severity grade is not needed for this change. The diagnosis should be modified with the tissue of origin (e.g., Thyroid gland - Ectopic tissue, thymus).references:
Hardisty JF, Boorman GA. 1990. Thyroid gland. In: Pathology of the Fischer Rat: Reference and Atlas (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 519–536. Abstract: http://www.ncbi.nlm.nih.gov/nlmcatalog/9002563
Hardisty JF, Boorman GA. 1999. Thyroid and parathyroid glands. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 537–554. Abstract: http://www.cacheriverpress.com/books/pathmouse.htm
Web page last updated on: August 08, 2014