Table of Contents
Definition / general | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: DePond WD. Inflammatory pseudotumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lymphnodesinflammatorypseudotumor.html. Accessed June 5th, 2023.
Definition / general
- One or many lymph nodes are affected
- Often fever, anemia, elevated erythrocyte sedimentation rate, hypergammaglobulinemia, prominent lymphadenopathy
- Usually benign / reactive, not neoplastic and so distinct from inflammatory myofibroblastic tumor at this site (Hum Pathol 2001;32:1382)
Case reports
- 9 year old boy with calcified tumor developing after FNA for Castleman disease (J Clin Pathol 1999;52:547)
- 31 year old woman with subsequent follicular dendritic cell tumor (Hum Pathol 2005;36:207)
Treatment
- Steroids, NSAIDs
Microscopic (histologic) description
- Varies from case to case
- Storiform pattern of spindled fibroblasts or myofibroblasts in fibrous stroma of node with extension into lymphoid tissue and perinodal tissue
- Vascular proliferation and mixed inflammatory infiltrate of plasma cells, immunoblasts, small lymphocytes, histiocytes, dendritic cells, neutrophils and fibroblasts
Microscopic (histologic) images
AFIP images
Inflammatory pseudotumor of lymph node
Contributed by Mark R. Wick, M.D.
Cytology description
- EBV+ cases may have Reed-Sternberg like cells (Diagn Cytopathol 2002;27:335)
Positive stains
- Vimentin, CD45 / LCA, CD68, actin
- Vascular endothelial growth factor (Int J Surg Pathol 2001;9:207), occasionally EBV
Molecular / cytogenetics description
- No clonal T cell receptor gene rearrangements
Differential diagnosis
- Anaplastic large cell lymphoma: see Am J Surg Pathol 2000;24:1537
- Kaposi sarcoma: involves entire node, has slit-like vascular spaces and extravasated red blood cells
- Mycobacterial spindle cell pseudotumor: HIV+
