To the Editor:

A 66-year-old immunocompetent woman presented with several days of high-grade fevers, chills, night sweats, and significant fatigue. Physical examination revealed bilateral axillary and supraclavicular lymphadenopathy, which raised concerns for malignancy. Initial laboratory testing showed leukocytosis with neutrophilic predominance, and inflammatory markers were elevated. Computed tomography of the chest, abdomen, and pelvis revealed widespread lymphadenopathy with no identifiable primary lesion; this also raised suspicion for lymphoma or metastatic disease.¹

Empiric broad-spectrum antibiotics were initiated. Surprisingly, blood cultures were positive for Pasteurella multocida. On further questioning, the patient recalled being scratched and occasionally bitten by her indoor cats, although she had no visible wounds. The diagnosis of zoonotic bacteremia shifted the clinical focus, but an axillary lymph node biopsy was performed due to the imaging findings. Histopathology confirmed CD10-positive small B-cell lymphoma. Ultimately, the patient had P multocida bacteremia and an underlying malignancy—a dual diagnosis that required careful, layered diagnostic reasoning.

This case highlights two key considerations for family physicians: (1) P multocida commonly colonizes in cats' mouths and can cause bacteremia in immunocompromised and immunocompetent patients, often without overt bite wounds²; (2) zoonotic infections can mimic malignancy by presenting with systemic symptoms and lymphadenopathy. Primary care physicians should be attuned to these possibilities and consider collecting detailed animal exposure histories when evaluating febrile patients with lymphadenopathy.³ This case also emphasizes the value of obtaining a thorough history, especially when differentiating infection from malignancy in a patient presenting with nonspecific constitutional symptoms.