EXTERNAL CONSULT:  
26 yrs lady was treated for TBC (pulmonary). Unexpectedly, thoracic soft tissue biopsy was performed ("protruding masses from mediastinum).  
 
CT 2017.05.18: Multinodular confulent infiltrative nodules with fibrosis. Retrosternally (right)- polycyclic solid nodules with destruction. Int he thoracic wall- identical nodule ~4,76cm with usuration of sternum. Infrathyroid right solid masses spreading in trachea surroundings. Similar masses in right pulmonary hilus. Hepatosplenomegaly.  
 
Blood: Eosinophilia up to 31%.  
 
HISTO: CD30+ CD15+ H and RS cells in background of massive eosinophilic infiltration, histiocytes, scant T or B cells and some multinucleated giant cells with emperipolesis.  
 
MOLECS: Clonality: not informative (degraded DNA).  
NGS: Single mutation detected: TP53:c.215C>G (p.P72R, COSMIC COSM250061). There were no other mutations.  
PANEL: CE-IVD Oncomine Solid Tumor DNA Kit (Thermo Fisher Scientific): EGFR, ALK, ERBB2, ERBB4, FGFR1, FGFR2, FGFR3, MET, DDR2, KRAS, PIK3CA, BRAF, AKT1, PTEN, NRAS, MAP2K1, STK11, NOTCH1, CTNNB1, SMAD4, FBXW7, TP53.  
 
 
PRIMARY version (before IH) was Langerhan's cell histiocytosis (Eo background, multiple histiocytes and giant multinucleated cells) vs CHL.  
 
DIAGNOSIS: Classic Hodgkin's lymphoma, unclassified (close to MC). IH: EBER(-); CD30/CD15+; Fascin+; EBV LMP1(-); Pax5+/-; CD79a/CD20/CD3/LCA(-);  
 
QUESTION: Peritumoral Rosai Dorfman like infiltration of giant histiocytes S100+ CD1a/Langerin(-) with emperipolesis?