Thymic follicular hyperplasia

Author: Hanni Gulwani, M.D. (see Authors page)

Revised: 14 June 2018, last major update December 2012

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Thymic follicular hyperplasia

Cite this page: Gulwani, H. Thymic follicular hyperplasia. website. Accessed July 22nd, 2018.
Definition / general
  • Defined as substantial numbers of lymphoid follicles in thymus of adults
  • Thymus usually has normal size / weight
Clinical features
  • Present in 65% with myasthenia gravis
  • Also associated with hyperthyroidism, Addison disease, SLE, early HIV, multilocular cysts, other immune related diseases
  • Often different clinical history than true thymic hyperplasia (Pathologica 2009;101:175)
Microscopic (histologic) description
  • Follicles with germinal centers, medullary epithelial cells may be disordered or hypertrophied
Microscopic (histologic) images

Images hosted on other servers:

Lymphoid follicles composed of B cells

Lymphoid follicles in the thymus in a patient with myasthenia gravis

Differential diagnosis
  • Normal lymphoid follicles of infants / children (few present)