<scp>EBER</scp> in situ hybridization in subcutaneous aluminum granulomas/lymphoid hyperplasia: A diagnostic clue to differentiate injection‐associated lymphoid hyperplasia from other forms of pseudolymphomas and cutaneous lymphomas

Background Subcutaneous vaccination or desensitization may induce persistent nodules at the injection sites. Without knowledge of prior injection, histopathological work-up be challenging. Objective Aim this study was to contribute unclear subcutaneous nodules, especially their differentiation from cutaneous lymphoma. Methods We retrospectively reviewed clinical data and slides four patients with which were suspected suffer T- B-cell Sections these cases 12 negative controls stained hematoxylin eosin a standardized immunohistochemical panel B- T-cell markers including EBER in situ hybridization as well electron microscopy. Results In all cases, large histiocytes granular cytoplasm compatible intracellular aluminum hydroxide present. revealed positive staining while absent controls. Limitations Post hoc completion medical history that specific immunotherapy had been applied before biopsy site only three out patients; one patient lost follow-up. Conclusion is an adjunctive tool differentiate aluminum-induced granuloma/lymphoid hyperplasia other forms pseudolymphoma lymphomas.