title: Actinomyces and actinobacillus actinomycetemcomitans-Actinomyces-associated lymphadenopathy mimicking lymphoma.
abstract: We present 2 unusual cases of long-standing, extensive reactive lymphadenopathy secondary to Actinomyces infection, 1 of which was also accompanied by Actinobacillus actinomycetemcomitans-Actinomyces complex infection. To our knowledge, histologic features of lymph node involvement by these organisms have not been previously reported in the literature. One patient had extensive cervical, posterior mediastinal, and abdominal lymphadenopathy. The second patient presented with a submandibular mass and cervical lymphadenopathy. Clinical features strongly suggested lymphoma. The histologic examination of the lymph nodes from both patients revealed reactive follicular hyperplasia, marked interfollicular and capsular fibrosis, and multiple interfollicular microabscesses. Characteristic Actinomyces colonies were identified at the center of the microabscesses in deep sections. Cultures were obtained from the lymph nodes of 1 patient, and were positive for A actinomycetemcomitans. Both patients had poor dental hygiene. Lymphadenopathy subsided with antibiotic therapy and appropriate dental care.
authors.affiliation: Department of Pathology, Baylor College of Medicine, Veterans Affairs Medical Center, Houston, TX 77030, USA.
authors.forename: M
authors.initials: M
authors.lastname: Amrikachi
authors.forename: B
authors.initials: B
authors.lastname: Krishnan
authors.forename: C J
authors.initials: CJ
authors.lastname: Finch
authors.forename: I
authors.initials: I
authors.lastname: Shahab
mesh_terms: D000188:Actinobacillus / Q000302:isolation & purification*; D000189:Actinobacillus Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D000190:Actinomyces / Q000302:isolation & purification*; D000196:Actinomycosis / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D000328:Adult; D000667:Ampicillin / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use; D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008198:Lymph Nodes / Q000382:microbiology / Q000473:pathology*; D008206:Lymphatic Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D008223:Lymphoma / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology; D008297:Male; D010406:Penicillins / Q000627:therapeutic use; D013365:Submandibular Gland Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology; D014057:Tomography, X-Ray Computed
chemical_list: D000890:Anti-Infective Agents; D010406:Penicillins; D002939:Ciprofloxacin; D000667:Ampicillin