Fibrin ring granulomas in Rickettsia typhi infection

Area of Science:

• Infectious Diseases
• Hematology
• Pathology

Background:

• Rickettsial infections can present with non-specific symptoms, complicating diagnosis.
• Fibrin ring granulomas are a rare histopathological finding, typically associated with other conditions.

Observation:

• A 71-year-old man presented with prolonged fever and cough, exhibiting anemia, thrombocytopenia, elevated liver enzymes, hyponatremia, and hypoalbuminemia.
• Extensive imaging and empirical antibiotic treatment failed to identify the fever source.
• Bone marrow biopsy revealed characteristic fibrin ring granulomas.

Findings:

• Rickettsial serologic testing confirmed Rickettsia typhi infection (murine typhus).
• The patient's fever resolved rapidly after doxycycline treatment.
• Fibrin ring granulomas were observed in the bone marrow of a patient with confirmed murine typhus.

Implications:

• This case suggests that fibrin ring granulomas may be a histopathological manifestation of murine typhus.
• The findings expand the spectrum of bone marrow findings associated with Rickettsia typhi infections.
• Recognizing this association could aid in the diagnosis of challenging rickettsial cases.