An 18-year-old male patient presented with a new, large, and tender lump under his left axilla for two weeks with associated chills, night sweats, and left thumb lesion for one week. The patient reported sleeping with his cat and experiencing a recent cat bite. His family history was significant for his grandmother with an unknown type of cancer in the axillary region. On physical examination, two tender subcutaneous nodules in the left axilla, measuring 5 cm and 1 cm in diameter, respectively, were discovered. On the left thumb, an erythematous and excoriated papule was noted. Given his clinical presentation, social history, family history, and physical examination, the differential diagnosis included lymphoma, reactive lymphadenopathy, abscess, deep epidermal inclusion cyst, and CSD. An ultrasound revealed enlarged left axillary lymph nodes with cortical thickening, measuring up to 33 mm, prompting further investigation with axillary lymph node biopsy (Figure ). On tissue examination of the biopsy, necrotizing lymphadenitis was identified, which is consistent with CSD. To confirm the diagnosis, serology for B. henselae was subsequently ordered resulting in an immunoglobulin G (IgG) titer against B. henselae of 1:256 and an immunoglobulin M (IgM) titer of >1:256. No monoclonal B-cell or abnormal T-cell populations were detected on flow cytometry.
A 25-year-old male patient with no significant past medical history presented with a three-day history of a tender mass in the right axilla along with fevers. The patient did not report any night sweats and weight loss. The mass showed no signs of drainage or infection. His physical examination revealed a 3 x 5 cm mobile, soft and non-nodular mass in the right axilla. An ultrasound of the right axilla showed a fluid-filled mass, which was concerning for an abscess. A needle aspiration was attempted without success; therefore, a referral to breast imaging clinic for a diagnostic ultrasound of the mass was initiated. Targeted ultrasound showed axillary lymphadenopathy at the site of the clinically palpable mass (Figure ). Ultrasound-guided biopsy was performed, and pathology revealed suppurative granulomatous lymphadenitis suggestive of CSD. Serology was not available for this case.