Mediastinum
Hematological neoplasms / lesions
MALT lymphoma

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

Revised: 20 June 2018, last major update December 2012

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

PubMed Search: MALT lymphoma mediastinum

Cite this page: Gulwani, H. MALT lymphoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mediastinumMALT.html. Accessed October 17th, 2018.
Definition / general
  • Very rare in thymus, < 20 cases reported
Clinical features
Case reports
Gross description
  • Centered in thymus
Microscopic (histologic) description
  • Clusters of centrocyte-like lymphoid cells in lymphoepithelial lesions mixed with mature lymphocytes and lymphoid follicles with reactive germinal centers
  • Also plasma cells
  • Variable microcysts
  • Early MALT cases in patients with thymic lymphofollicular hyperplasia and myasthenia gravis or connective tissue disease have ill defined lymphoid follicles with sheets of centrocyte-like B cells disrupting the medullary epithelial cytokeratin network
Microscopic (histologic) images

Images hosted on other servers:

Thymic tumor

Positive stains
Negative stains
Electron microscopy description
  • Nuclei with irregular protrusions or blebs
  • No intercellular junctions, no cytoplasmic filament bundles, neurosecretory granules, synaptic vesicles, microtubules, basal lamina, cytoplasmic processes or primitive sarcomeres
Molecular / cytogenetics description
  • Trisomy 3 may play a role in lymphoma development (Pathol Int 2012;62:93)
  • Thymic MALT lymphomas have a characteristic pattern of chromosomal aberrations that may be similar to those of other autoimmune associated MALT lymphomas
  • Monoclonal IgH rearrangement present (Am J Clin Pathol 2002;117:51)