An 84-Year-Old Man With an Axillary Mass

Correct answer. C. Lymphoma

Although most lymphadenopathy encountered in primary care is benign, clinicians must consider malignancy in older adults. This patient had several high‑risk features, including risk increases with age, node size >3 cm, fixed character, lack of tenderness, and supraclavicular or generalized lymphadenopathy.^1–3 Ultrasound-guided tissue sampling, including fine-needle aspiration and core needle biopsy, confirmed diffuse large B-cell lymphoma (DLBCL).

Differential diagnoses. We considered a broad differential diagnosis in evaluating this patient’s initially apparent right axillary lymphadenopathy.

Infectious mononucleosis often presents with fatigue, pharyngitis, and prominent cervical lymphadenopathy, particularly in adolescents and young adults. However, the absence of pharyngitis, constitutional symptoms, and the unusual lack of cervical involvement made this diagnosis unlikely.⁵ Additionally, axillary lymphadenopathy alone is rarely the primary presentation in Epstein–Barr virus infection.

Coccidioidomycosis, endemic in Arizona, was another consideration, given the patient’s geographic location. Typical manifestations include fever, cough, and pulmonary infiltrates accompanied by hilar adenopathy.⁶ Although lymphadenitis can occur, especially in the setting of primary pulmonary infection, this patient lacked respiratory symptoms, had no pulmonary abnormalities on chest radiography, and demonstrated lymphadenopathy outside the expected hilar distribution. These findings made coccidioidomycosis-related lymphadenitis less likely.

Male breast cancer was also considered because it can metastasize to ipsilateral axillary lymph nodes. Risk factors include advancing age, BRCA2 gene alterations, prior chest irradiation, and a family history of breast cancer.⁷ Although no palpable breast mass or known major risk factors were identified in the available history, these findings did not exclude the diagnosis. Tissue diagnosis ultimately confirmed lymphoma rather than carcinoma.

Reactive lymphadenitis following COVID-19 vaccination was considered because ipsilateral axillary lymphadenopathy can occur after vaccination in the ipsilateral arm.⁸ However, this patient’s presentation was atypical for a benign vaccine reaction because the mass was large, firm, fixed, progressive, and associated with additional supraclavicular and paratracheal lymphadenopathy. Thus, vaccine-associated lymphadenitis was considered but did not adequately explain the clinical and imaging findings.

Treatment and management. The patient was referred to hematology-oncology and initiated on standard rituximab‑based multiagent chemotherapy for DLBCL, with “R-CHOP” (rituximab/cyclophosphamide /doxorubicin/vincristine /prednisone).

Treatment is typically tailored according to staging studies and performance status. Our patient underwent 6 cycles of treatment over the course of about 6 months. He received appropriate prophylaxis (Acyclovir 400 mg twice daily) for shingles. He also received sulfamethoxazole and trimethoprim (Bactrim DS) 1 tab on Monday, Wednesday, and Friday for Pneumocystis jirovecii pneumonia (PJP) prophylaxis; pantoprazole 40 mg daily to prevent stomach ulcers from high-dose steroids; Pegfilgrastim (Neulasta) with every cycle; and Loratidine (Claritin) 10 mg on days 1-7 of every chemotherapy cycle to prevent bone pain from Neulasta. He had the necessary supportive care, particularly given his advanced age, of physical and occupational therapy services.

Outcome and follow-Up. The patient began appropriate oncologic therapy and demonstrated complete resolution of his tumor burden. He entered an observation phase where he continued to have no evidence of disease. Unfortunately, after completing treatment, he suffered a fall with multiple fractures, including a traumatic intracerebral hemorrhage, and died.

Discussion. Lymphadenopathy is a common finding in primary care, but identifying features that differentiate benign from malignant conditions is critical. Only 1% to 2% of lymphadenopathy cases in primary care ultimately represent malignancy.¹ The MIAMI—malignancy, infection, autoimmune, miscellaneous, iatrogenic—offers a practical structure for evaluating etiologies.^2–4

This patient’s presentation raised suspicion early due to his age, node size, and the presence of multiple abnormal nodes, including supraclavicular involvement. Supraclavicular lymphadenopathy has greater predictive value for malignancy than axillary involvement alone.³

Primary care physicians and advanced practice providers should avoid diagnostic anchoring. Although the patient associated his axillary swelling with a recent COVID-19 vaccination, recent vaccination should not delay evaluation of lymphadenopathy that is large, fixed, progressive, persistent, supraclavicular, or associated with additional nodal stations. Indeed, a 2022 systematic review found that COVID‑19 vaccine–associated lymphadenopathy typically occurs within 7 days post‑vaccination, with a mean node size <2 cm, and resolves within 4–5 weeks.⁸

In this case, early cross-sectional imaging and biopsy allowed prompt diagnosis and initiation of appropriate oncologic therapy, underscoring the importance of integrating patient history with physical examination and imaging to guide workup and avoid delayed diagnosis.

AUTHOR:
Michael L. Grover, DO¹

AFFILIATIONS:
¹Associate professor, Mayo Clinic, Scottsdale, AZ, USA

CITATION:
Grover ML. An 84-year-old man with an axillary mass. Consultant. Published online June 9, 2026. DOI: 10.25270/con.2026.05.000004

DISCLOSURES:
The authors report no relevant financial relationships.

ACKNOWLEDGEMENTS:
The author (MLG) obtained informed consent from the patient for publication of this case report shortly after his presentation.

CORRESPONDENCE:
Michael L. Grover, DO. Mayo Clinic. 13400 E. Shea Blvd, Scottsdale, AZ 85259, USA (grover.michael@mayo.edu)

References

1. Fijten GH, Blijham GH. Unexplained lymphadenopathy in family practice: An evaluation of malignancy probability and physician workup. J Fam Pract. 1988;27(4):373–376.
2. Gaddey HL, Riegel AM. Unexplained lymphadenopathy: Evaluation and differential diagnosis. Am Fam Physician. 2016;94(11):896–903.
3. Habermann TM, Steensma DP. Lymphadenopathy: Differential diagnosis and evaluation. Mayo Clin Proc. 2000;75(7):723–732.
4. Alberta Health Services and Primary Care Networks. Lymph Node Assessment Primary Care Pathway. Updated December 2024.
5. Sylvester JE, Buchanan BK, Silva TW. Infectious mononucleosis: Rapid evidence review. Am Fam Physician. 2023;107(1):71–78.
6. Herrick KR, Trondle ME, Febles TT. Coccidioidomycosis (Valley Fever) in primary care. Am Fam Physician. 2020;101(4):221–228.
7. Giordano SH, Buzdar AU, Hortobagyi GN. Breast cancer in men: Epidemiology, diagnosis, and treatment. Ann Intern Med. 2002;137(8):678–687.
8. Co M, Wong PCP, Kwong A. COVID‑19 vaccine–associated axillary lymphadenopathy: A systematic review. Cancer Treat Res Commun. 2022;31:100546.

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