The hypothesis of FDCS was entertained in this small biopsy but the definitive diagnosis was made on the surgically excised tonsil. In the small biopsy, without immunohistochemical findings, one could take into consideration also the following differential diagnoses: lymphoepithelioma-like carcinoma, Langerhans’ cell histiocytosis, nodular sclerosing Hodgkin’s lymphoma with a prominent fibrohistiocytic component, a granulomatous process. The tonsil measured cm 3.5x2.5x2. Immunohistochemistry showed a strong expression of CD23, CD21 and Vimentin
Figura_8 ,
Figura_9 while Cytokeratin and EMA
Figura_10 , S100P, CD30, muscle specific actin, ALK-1 were not expressed. CD68 decorated a histiocytic cellular component intimately admixed to dendritic cells
Figura_9 . The tonsil is a relatively common site of involvement of this rare tumor
1 . In this case many areas of the lesion showed a prominent inflammatory pseudotumor-like appearance. In addition, tumor cells displayed nuclear pleomorphism with grooves and folds. There were occasional multinucleate cells and some atypical large cells with prominent nucleoli simulating Reed-Sternberg cells
Figura_11 . These findings suggest that the case might represent an example of the “inflammatory pseudotumor-like” variant of FDCS which otherwise seems to occur exclusively in intra-abdominal sites
2 . The in situ hybridization for EBV-encoded RNA has not been performed yet. The patient is well and alive 4 months after the diagnosis. At the time of surgery, imaging techniques and PET-scan seemed to exclude any additional site of disease involvement. Thank you all for the interesting comments.
