Kikuchi-Fujimoto disease following SARS-CoV-2 vaccination

Abstract

A previously healthy Japanese woman in her 20s was admitted to our hospital with a 2-week history of fever (39.0°C) and a 1-week history of painful cervical lymphadenopathy. The day before fever onset, she had received her first Pfizer-BioNTech SARS-CoV-2 vaccine in her left arm. She had previously been treated with empirical antibiotics with no improvement. Physical examination revealed painful lymphadenopathy in both posterior cervical regions. CT showed symmetrical lymphadenopathies in the neck, supraclavicular, axillary and inguinal regions as well as hepatosplenomegaly. We suspected lymphoma and performed a lymph node biopsy in the right inguinal region, which revealed necrotising histiocytic lymphadenitis. The patient was, therefore, diagnosed with Kikuchi-Fujimoto disease (KFD). She improved after the corticosteroid therapy. This report highlights the importance of including KFD as a differential diagnosis of lymphadenopathy after SARS-CoV-2 vaccination. Additionally, lymph node biopsy is helpful for diagnosing KFD because it rules out other entities.

COVID‐19 post‐vaccination lymphadenopathy: A review of the use of fine needle aspiration cytology

“…No restrictions were placed on the year of publication. Only literature published in English was selected, including studies that reported histopathological and/or cytological findings in vaccine‐related lymphadenopathy 17,20,22,23,35–64 . Studies on SLDI, which was generally detected by 18F‐FDG PET‐CT, were also selected and used for the general comprehension and description of the phenomenon and to retrieve cases evaluated by histology or LN‐FNAC 65–68 .…”

“…While most cases of SLDI do not show clinically evident enlargement of lymph nodes, an awareness of SLDI among doctors is of fundamental importance in a variety of clinical contexts, particularly with regard to cancer staging and follow‐up to avoid the risk of overdiagnosis. In our research, surgical excision or CNB of C19‐LAP‐ or SLDI‐enlarged lymph nodes have been performed in 55 cases 20,22,23,35,39,41–43,47,49–63 . The histological diagnoses were as follows: negative for neoplasia, reactive hyperplasia, and florid reactive hyperplasia (39 cases), 23,39,50–61 progressive transformation of germinal centres (1 case), 54 atypical follicular hyperplasia with light chain‐restricted germinal centres (1 case) 62 granulomatous reaction (2 cases), 50,63 metastases (4 cases), 20,22,50 Kikuchi‐Fujimoto disease (KFD; 6 cases), 40–42,49,56,64 Rosai‐Dorfman‐Destombes disease (RDD; 1 case), 48 and Langerhans cell histiocytosis (LCH; 1 case) 57 .…”

“…In our research, surgical excision or CNB of C19-LAP-or SLDI-enlarged lymph nodes have been performed in 55 cases. 20,22,23,35,39,[41][42][43]47,[49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] The histological diagnoses were as follows: negative for neoplasia, reactive hyperplasia, and florid reactive hyperplasia (39 cases), 23,39,[50][51][52][53][54][55][56][57][58][59][60][61] progressive transformation of germinal centres (1 case), 54 atypical follicular hyperplasia with light chain-restricted germinal centres (1 case) 62 granulomatous reaction (2 cases), 50,63 metastases (4 cases), 20,22,50 Kikuchi-Fujimoto disease (KFD; 6 cases), [40][41]…”

“…Lymph node excision and core-needle biopsy (CNB) were the most frequently performed procedures for the pathological evaluation of COVID-19 post-vaccine lymphadenopathy. We retrieved 48 cases of C19-LAP with histological control (excision or CNB ) 22,23,39,43,48,49,51,53,56,57,61,62 and diagnosed as negative or reactive with or without follicular hyperplasia (37 cases). Two cases were reported as florid lymphoid hyperplasia 54,57 ; KFD was reported in four cases 37,39,49,56 (16.7%).…”

“…We retrieved 48 cases of C19-LAP with histological control (excision or CNB ) 22,23,39,43,48,49,51,53,56,57,61,62 and diagnosed as negative or reactive with or without follicular hyperplasia (37 cases). Two cases were reported as florid lymphoid hyperplasia 54,57 ; KFD was reported in four cases 37,39,49,56 (16.7%). Larkin et al 54 reported a focal increase in Epstein-Barr Virus (EBV)-positive cells, with other findings suggestive of prior infection.…”