Pleura & peritoneum

Pleura other tumors

Nodular histiocytic hyperplasia

Last author update: 1 May 2014
Last staff update: 1 November 2023

Copyright: 2003-2024,, Inc.

PubMed Search: Nodular histiocytic hyperplasia

Vaidehi Avadhani, M.D.
Page views in 2023: 1,951
Page views in 2024 to date: 721
Cite this page: Avadhani V. Nodular histiocytic hyperplasia. website. Accessed April 14th, 2024.
Definition / general
  • Small nodular aggregates of histiocytes with mesothelial cells scattered in the aggregates or in clusters
  • Nodular mesothelial hyperplasia, mesothelial / monoytc incidental cardiac excrescences (MICE), nodular histiocytic / mesothelial hyperplasia
  • Lesions have been described in lung, pleura, hernia sac, pericardium, peritoneum
  • Hypothesis: trauma, tumor or inflammation lead to histiocyte / mesothelial expression of CD34 and adhesion molecules, which lead to aggregates of histiocytes and mesothelial cells through cell-cell interactions
Clinical features
  • Almost always an incidental finding
Case reports
  • None required; an incidental finding
Clinical images

Images hosted on other servers:

Pericardial nodule over arch of aorta

Microscopic (histologic) description
  • Compact nodular collections of polygonal to oval cells with indistinct cell borders and moderate cytoplasm
  • Nuclei are oval to angulated with grooves (usually) and inconspicuous nucleoli
  • Mitoses may be present but no atypical mitoses
  • Hemosiderin laden macrophages may be present
  • Also present are scattered indistinguishable bland cuboidal to polygonal cells with moderate cytoplasm, which show cytokeratin and calretinin staining, indicating their mesothelial origin
Microscopic (histologic) images

Images hosted on other servers:

Hernial sac: H&E, CD68, CD1a


Pericardium: vimentin+, CD68+, S100+

Cytology description
  • Similar nodular aggregates have also been described in cell block material from serous effusions - this is the most important pitfall in cytodiagnosis of serous effusions (Diagn Cytopathol 2002;26:68)
Positive stains
Negative stains
Differential diagnosis
Back to top
Image 01 Image 02