77 yrs old lady underwent inguinal lymphnodectomy due to "suppuration".  
Virtual slides: Apperio.  
Photo: from virtual slides.  
HE: Sinusoid, slightly nodular and difusse perinodal infiltrate of large- medium sized cells with oval vesiculated, "anaplastic" lobated and rarelly wrinckled nuclei and admixture of eosinophils and plasmacytes. Prominent central necrosis is present.  
IH: CD68+; S100+ ; CD4+; Bcl6+; CD1a+<5% (sic!);  
PanCK/EMA(-); CD20/CD79a/Pax5(-); Igkappa/lambda(-); CD3(-); HMB45/MelanA(-); CD21/CD23(-); Ki67(+/+++) 60%; CD30(-); TdT/CD34/CD117(-); CD15/MPO(-); Mum1(-);  
 
PARALEL SIMILAR PEDIATRIC CASE: https://www.ipath-network.com/ipath/object/view/1333  
 
PROPOSAL: Langerhans cell sarcoma in the lymph node with perinodal spread.  
Thank you for being 2gether.

tzankov 2009-10-27 09:52	Dear Ugnius,   indeed there are many arguments for a histiocytic/dendritic cell neoplasm/sarkoma. To be sure to exclude a T-cell lymphoma, I would extend the pannel to CD2, CD3 and CD5 as well as add lysozyme and, if you have it, langerin. CD1a is very focal so that I ask myslef if it does not stain preexisting Langerhans cells, which are rather numerous in inguinal lymph nodes, and not tumor cells? Can you add images of morphologically unequivocal tumor cells staining for CD1a?
diane.c.farhi 2009-10-27 15:27	I agree with Dr. Tzankov's comments. I would add only that the patient should be examined for other lesions consistent with Langerhans cell histiocytosis, in order to classify the tumor appropriately. B cell clonal disease (e.g., CLL) might also be sought, as histiocytic tumors/malignancies have been reported in patients with CLL. In such cases, the histiocytic and B cell tumors share a clonal origin. This is a rare occurrence, but in light of this patient's age, might be a possibility. It would be easy to check for CLL and other B-cell tumors at the same time as checking for other sites of histiocytic disease.
ugnius 2009-10-27 15:33	Thank you. All requested/possible stains (except lysozyme: out of my possibilities unfortunatelly) will be posted in soon. Hopefully the patient will be redirected to hematology-oncology center for further evaluation. I'm not quite sure about DEFINITELLY POSITIVE TUMOR cells CD1a+. Some cells and clusters are positive at least. I wil try to find some.
hurwitz 2009-10-27 16:51	This is certainly a malignant hematolymphoid neoplasm.I agree with the reservation about langerhas' cell histiocytosis, the morphology does not support this assumption and the few scattered CD1a+ population represents most probably preexisting reactive cells. GHowever one image shows a large cluster of S-100+ cells. Could we see them on high power in order to appreciate their morphology? Did you see similar clusters of CD1a+ cells? To the T-cell panel suggested by Dr.Tzankov I would ask to add CD7, since CD3 apparently has been negative
ugnius 2009-10-29 12:00	My Dears, all T markers are complettelly negative: CD2/CD5/CD7/CD56/CD57/GranB. We are trying to get e-microscopy picture of these histyocytes. Unfortunatelly I have no other histyoid markers.
ugnius 2009-10-29 12:15	Please find some CD1a+ atypical cells (SINGLES only) with superwrincled nuclei.
tzankov 2009-10-29 16:03	Thank you Ugnius. All additional stainings support the idea of a histiocytic/dendritic cell neoplasm/sarcoma. Let's wait for ELMI...
anpo 2009-11-05 17:08	I am not an expert of these tumors but when I looked up in the WHO book the immunophenotype with S100++ CD68+ CD1a neg is mostly consistent with Inderdigitating dendritic cell sarcoma, morphology also can fit.
ugnius 2009-11-14 17:53	Thanx a lot for opinions. E-microscopy is in very slow progress due to technical problems... I will inform you in a case.
hurwitz 2010-01-04 11:41	We can accept the diagnosis of an interdigitating dendritic cell tumor as the most probable one, till we will have the results of EM. Then, if necessary we can take up the case and discuss it again.
ugnius 2010-01-04 11:58	Thank all of you. Unfortunatelly the patient passed away without hemato-evaluation in peripoheral hospital. I will check clinical explanations of death. Interdigitating cell sarcoma idea is pretty good: e-microscopy does not reveal Birbeck granules, but quality is still low (parafin). I will post some pictures after final evaluation. All the Best for Hemato Group in 2010.
ugnius 2010-05-24 15:24	The case was sent to external consultation to dr.A.Tzankov and dr.S.Dirnofer (Basel, Swiss). Additional IH: S100+ focal; CD68+ (dotted); CD11c+ (membranous); CD163+ (strong); Lyzocyme+ (weak); Ki67 fraction about 60%; CD4+. Due to: single cell only CD1a+; focal S100+; lacking spindle cell pattern; necrosis... FINAL DIAGNOSIS: HISTIOCYTIC SARCOMA IN THE LYMPH NODE.   Additional photos: courtesy of dr.A.Tzankov.   The case was presented in 7th Baltic Hematology congress in tartu, Estonia.
tzankov 2010-05-25 06:57	After reviewing this case at the microscope and with the information that there were no Bierbeck structures at ElMi, we can close the case now. The final diagnosis is     HISTIOCYTIC SARCOMA IN THE LYMPH NODE     Thanks to Ugnius for this case and to all the participants for their comments.