A 58-year-old woman presented with breast and rib pain. She reported left axillary lymphadenopathy, abdominal fullness, and malaise. She denied fever and breast drainage. Her past medical history was significant for hepatitis C. Socially, she had two cats and was bitten by a cat a month prior. Review of systems was positive for fatigue and negative for appetite change, chills, diaphoresis, and fevers. Lung cancer screening CT, which was completed a day prior to this visit, showed an ill-defined mass measuring up to 3.5 cm in the left axilla. There was mild adjacent soft tissue stranding. These findings indicated an infectious, inflammatory, or malignant process. She was promptly treated with doxycycline for CSD, but also recommended to obtain a diagnostic mammogram and an ultrasound of the left axilla. The imaging showed an enlarged lymph node with an adjacent abscess, which altogether measured 30 x 17 mm in the left axilla (Figure ).\nTherefore, a lymph node biopsy and drainage of the abscess with culture were ordered. The lymph node biopsy revealed necrotizing granulomatous inflammation with the following differential diagnosis: CSD, tuberculosis, and other infectious entities. The abscess culture was negative for aerobic/anaerobic organisms and showed few polymorphonuclear leukocytes. Given her history of a cat scratch, symptoms, and pathology results, an infectious etiology was most likely. To confirm the diagnosis and rule out other causes, serology for B. henselae was ordered which showed high B. henselae IgG titer of >1:1024 and IgM titer of 1:128.
A 49-year-old woman presented with arm pain for five days. The pain was located in the right armpit and sensitive to touch. The patient also reported bilateral ear pain. There were no chills, fevers, or night sweats. The patient had a normal screening mammogram five months prior. Her family history was significant for her mother with breast cancer and her father with gastric cancer. Socially, she had two cats. On physical examination, there was a painful mass below the right armpit with no overlying skin lesions. Because of the location of the mass and the family history of breast cancer, a repeat mammogram and an ultrasound were recommended. The imaging results were remarkable for a morphologically abnormal right axillary lymph node measuring 31 mm in diameter (Figure ). Ultrasound-guided biopsy was performed, and the surgical pathology exam results were consistent with cat scratch lymphadenopathy. Flow cytometry revealed no detectable monoclonal B cells or immunophenotypically aberrant T cells, which diminished the concern for malignancy. Serology was not available for this case.