Pleura & peritoneum
Pleura other tumors
Nodular histiocytic hyperplasia
Author: Vaidehi Avadhani, M.D.
Last author update: 1 May 2014
Last staff update: 1 November 2023
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Nodular histiocytic hyperplasia
Table of Contents
Definition / general | Terminology | Sites | Pathophysiology | Clinical features | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Differential diagnosisCite this page: Avadhani V. Nodular histiocytic hyperplasia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pleuranodularhistiohyper.html. Accessed December 1st, 2024.
Definition / general
- Small nodular aggregates of histiocytes with mesothelial cells scattered in the aggregates or in clusters
Terminology
- Nodular mesothelial hyperplasia, mesothelial / monoytc incidental cardiac excrescences (MICE), nodular histiocytic / mesothelial hyperplasia
Sites
- Lesions have been described in lung, pleura, hernia sac, pericardium, peritoneum
Pathophysiology
- 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
- 2 year old boy, 23 and 78 year old women, 74 year old man (Am J Surg Pathol 1998;22:285)
- 5 cases: peritoneal, pulmonary, pericardial (Ann Diagn Pathol 2004;8:115)
Treatment
- 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
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
- Two populations: histiocytes (CD68+), mesothelial cells (cytokeratin+, calretinin+)
Differential diagnosis
- Endometriosis
- Leukemia / lymphoma
- Metastatic adenocarcinoma / carcinoma
- Mesothelioma
- Reactive / florid mesothelial hyperplasia: generalized, in contrast to the localized nodular histiocytic proliferation in this lesion
