Beschreibung:
Rationale: The diagnosis of lymphoma in routine diagnostics can be challenging due to clinical, morphological and immunphenotypical overlap with unusual reactive processes termed “pseudolymphomas.” Patient concerns: 45-year-old male that underwent surgical debridement for a necrotizing fasciitis of the thigh with concomitant excision of a regional lymph node. Diagnoses: The lymph node demonstrated an architecture-effacing activation and proliferation of lymphoblasts and was initially misdiagnosed as an aggressive lymphoma. Only in consideration of the clinical context and with the help of additional immunohistochemical and molecular analyses the final diagnosis of a reactive lymphadenopathy could be made. Interventions: No further therapy was required after the final diagnosis of a reactive lymphadenopathy was made. Outcomes: The clinical follow-up was unremarkable, with no evidence of residual disease after 6 months. Lessons: This case report adds the parafollicular activation and proliferation of blasts and plasmablasts in the drainage area of an active infection to the spectrum of “pseudolymphomas” and reiterizes the importance of placing histopathological findings in the proper context.