Pediatric Bacterial Lymphadenitis: An Eight-Year Experience at a Large Academic Center
FG Nunes, D Itani, SL Cook, R Verrall, C Stratton, CA Mosse. Vanderbilt University Medical Center, Nashville, TN
Background: Infectious lymphadenitis is a common disease in children with numerous etiologies. An accurate differential from a lymph node biopsy can expedite diagnosis and minimize ancillary testing. There are few published case series that compare the histopathology of uncommon pathogens such as Francisella tularensis with more common agents.
Design: We reviewed all lymph node biopsies showing lymphadenitis in immunocompetent children under the age of 15, from July 2000 to June 2008. Age, site, pattern of inflammation, and results of AFB stains, culture and DNA hybridization were assessed.
Results: Thirty-five cases fulfilled the inclusion criteria. These represented 21 cases of Mycobacterium avium complex (MAC) (60%), 1 Mycobacterium fortuitum (3%), 7 Bartonella henselae (20%), 2 Yersinia entercolitica (7%), 1 Francisella tularensis (3%) and 1 Streptococcus pyogenes (3%). The mean age of mycobacterial patients was 2.2 years old; 9 (42%) were found in submental lymph nodes and 4 out of 21 (19%) showed AFB positivity. Eighteen cases (86%) had caseating granulomas as their sole histopathologic finding. Conversely, Bartonella and Francisella affected older children (9.8 yo mean) and typically showed extensive granulomatous and suppurative necrosis. Streptococcus and Yersinia had extensive suppurative necrosis as the only finding (see table). Interestingly, Yersinia was found in an inguinal lymph node and not in a mesenteric lymph node as usually described.
Conclusions: We believe MAC should always be considered in young children with caseating granulomatous lymphadenitis. Because the sensitivity of AFB for mycobacterial infections is very low (19% in this study), molecular techniques should be regularly employed. Cat-scratch disease and tularemia should be investigated in older children presenting with both abscesses and granulomas, notwithstanding the lack of stellate microabscesses. Yersiniosis should be suspected in young children presenting with extensive suppurative necrotizing lymphadenitis. These distinct clinical and histological patterns may help direct ancillary testing to minimize expense and time to diagnosis.
Monday, March 9, 2009 1:00 PM
Poster Session II # 189, Monday Afternoon