A Case of Cutaneous T-cell Lymphoma: The Importance of a Dermatology Consultation

Mycosis fungoides (MF), the predominant variant of cutaneous T-cell lymphoma (CTCL), typically manifests as pruritic patches, plaques, and tumors, often mimicking cellulitis. Misdiagnosis of cellulitis has led to substantial avoidable healthcare costs, unnecessary hospitalizations, increased risk of nosocomial infections, and antibiotic resistance. We report a case of cellulitis misdiagnosis in a patient with a history of MF. A 68-year-old male referred from plastic surgery due to suspected worsening of left lower leg cellulitis despite recent antibiotic treatment presented to the hospital. While admitted, the patient underwent a computed tomography scan, which revealed increased diffuse subcutaneous soft tissue changes in the ankle and medial thigh regions with several focal areas suspicious for tumor involvement. The patient received intravenous antibiotics with a plan for surgical debridement and possible amputation per plastic surgery recommendation. Oncology and infectious disease were also consulted as part of the multidisciplinary approach, and a dermatology consultation was recommended, which included a punch biopsy. Results were consistent with an atypical dermal lymphoid infiltrate consistent with CTCL. The patient was discharged with a one-week course of cephalexin and restarted brentuximab per oncology. During follow-up, the patient showed improvement with less erythema and swelling. Delays in CTCL treatment can worsen prognosis. The ALT-70 tool aids in excluding cellulitis. This case underscores the necessity of dermatology consultation for accurate diagnosis, aiming to avert future misdiagnoses and inappropriate treatment of skin conditions resembling cellulitis, such as MF.