74 yrs female presenting with enlarged lateral neck lymph nodes up to 5cm. All 3 biopsies (large nodes) shows the same changes- named as "reactive".  
HISTORY: previous resection of goiter.  
HISTO: Vaguelly nodular spindle cell/histiocytic proliferation in the node with admixture of polytypic plasmacytes/lymhocytes. Peripheral lymph node architecture is blurred with residual follicles with focally prominent marginal zones and nodule forming in MZ projection/ interfollicular space. Any definitelly LYMPHOPROLIFERATION is visible, except histiocytic nodules. Focal cellular accumulation of atypical cells with large vesiculated nuclei (as in IMFT) and multilobated nuclei in some nodules present. Mitoses up to 2/10 DPRL.  
IH: Spindle cells CD23/CD21/S100/D2-40/EMA/PanCK/Desmin/Asm Actin/MelanA(-), ALK1 (new sensitive for lung AC) CD68/Lysozyme (?)(single cells +?); LCA/HLA-DR(-)(?)(mainly multiple small-medium spindle macrofages +); CD43(-); INI1+; In part FXIIIa+... Ki67 index low.  
GIant cells: clearly CD68+LCA+.  
IgG4/IgG ratio not so prominent.  
MOLECS: IGH ir IGK polyclonal. NOTE: IGH FR1 slightly atypical profile (small clone?), but formally (quantitativelly) negative.  
TCRB ir TCRG polyclonal.  
EBER and additional (deeper) IH: pending.  
PHOTOS: multiple blocks- the last digit means block number.  
TECHNO NOTE: parafin blocks are suboptimal quality: ih stains flow out...  
 
PROPOSAL/DIFFERENTIAL: a) low grade mesenchymal/fibroblastic dendritic neoplasia, probably (fibroblastic reticular) dendritic cell sarcoma/tumor with "O" phenotype? Or just IMFT- metastatic vs primary(?);  
b) B marginal zone lymphoma with exuberrant histiocytic/fibroblastic/dendritic(?) proliferation or IgG4 disease?  
REALLY I feel missing something else...

tzankov 2014-01-28 18:13	Except for vimentin, I am not sure that we sufficiently characterized the atypcial spindle cells. Is it possible to stain for CD43, CD45, CD163, CD14, CD11c, HLA-DR, Langerin and CD1a. I think that any dendritic/histocytic neoplasm should be excluded prior starting thinking of B-cell lymphomas of IgG4 disease. Is the respective lymph node draining any regions with special/specific changes? Any clinical history of skin diseases incl. melanoma?
ugnius 2014-01-29 07:11	From clinical history: only goiter resection (any mentioned diseases in the region)... Despite low grade evolution/reccurency I cannot see any pure definite spatial neoplastic signs of spindle cells- seems like beeing co-population of another process, spreading in systematic fashion in the lymph nodes for 3 yrs... Maybe fibroblastic dendritic cell neo (or FDC totally nagative) with totally nagative IH is still possible? But usually we see MORE CONDENSED/CELLULAR and PURIFIED DC tumors in reccurrencies?   I will try to scan all required IH soon...
ugnius 2014-02-05 11:02	Please more pleomorphic cell nodule exposed on reblocked material (half oc block 2): it seems, that some cells Lysozyme+ > CD68+, but LCA negative (background +is prominent).   Mitoses scarse, but foundable.     So, it sounds like "low grade dendritic cell tumor/sarcoma"- fibroblastic/reticular? other?
ugnius 2014-02-05 11:19	Article: Hum Pathol. 2001 Dec;32(12):1382-7.   Inflammatory pseudotumor of lymph node and spleen: an entity biologically distinct from inflammatory myofibroblastic tumor.   Kutok JL, Pinkus GS, Dorfman DM, Fletcher CD.   PMID: 11774173
tzankov 2014-02-05 19:19	Considering all, the gross histoarchtiecture, the admixture of plama cells and the phenotype, I think that "inflammatory pseudotumor" (old designation: plasma cell granuloma) might be the best working hypothesis.
ugnius 2014-02-06 08:10	Thanx. Maybe hypothesis about IgG4 (link with "pseudotumor") may be evolved additionally (to check IgG/IgG4 in blood)?
kunze 2014-02-07 21:19	Reviewing the images and the virtual slides I favor as well an inflammatory pseudotumor with a predominant spindle cell proliferation and numerous plasma cells. The immunoprofile is not compatible with a FDCS or IDCS.
ugnius 2014-02-08 10:52	Thank you a lot for continuous support.
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