BACKGROUND We report a 43-year-old man with ulcerative lesions of the right arm without pulmonary symptoms that was diagnosed as cutaneous lymphomatoid granulomatosis, a rare Epstein Barr virus-associated angiocentric and angiodestructive lymphoproliferative disorder that most commonly involves the lungs. Cutaneous involvement usually occurs in association with pulmonary disease, while isolated cutaneous disease is rare and most often presents with papules, nodules, or plaques. Necrotizing ulcers are uncommon and can closely mimic other dermatologic conditions. CASE REPORT A 43-year-old man presented with a 6-month history of chronic necrotizing ulcers of the right upper arm, accompanied by low-grade fever and malaise. Laboratory investigations revealed mild leukopenia, normocytic anemia, mildly elevated inflammatory markers, and impaired renal function. Blood cultures and interferon-gamma release assay for tuberculosis were negative. Magnetic resonance imaging of the right arm demonstrated findings consistent with myonecrosis involving the brachial and brachioradialis muscles. Wound biopsy cultures were negative for bacterial, fungal, and mycobacterial organisms. Histopathologic examination, immunohistochemical analysis, and positivity for Epstein-Barr virus-encoded RNA established a diagnosis of grade 3 lymphomatoid granulomatosis. Further evaluation revealed nonspecific findings on chest computed tomography and end-stage kidney disease, necessitating initiation of hemodialysis. The patient was discharged after a 4-week hospitalization with plans for outpatient oncology and nephrology follow-up. CONCLUSIONS Isolated cutaneous lymphomatoid granulomatosis is a rare but important diagnostic consideration in patients with chronic necrotizing skin ulcers and negative infectious evaluations. Early histopathologic assessment, including testing for Epstein-Barr virus, is essential for timely diagnosis and appropriate management.