Nasal type of extranodal NK/T-cell lymphoma presenting as an atypical skin defect: A case report.

RATIONALE: Nasal-type extranodal natural killer/T-cell lymphoma (ENKTL) is a rare malignancy primarily affecting the upper aerodigestive tract. It is strongly associated with Epstein-Barr virus (EBV) infection; thus, EBV-negative cases are extremely rare, and their clinicopathological features and treatment responses are not well defined.

PATIENT CONCERNS: A 75-year-old male presented with a persistent skin defect in the medial canthal area of the left eye. He had been treated with antibiotics for presumed cellulitis for 2 months, but the symptoms persisted, and the skin defect worsened.

DIAGNOSES: Surgical debridement revealed an irregularly shaped white mass extending into the paranasal sinus. Incisional biopsy revealed atypical lymphocytic infiltration favoring ENKTL. EBV in situ hybridization was negative, supporting the diagnosis of EBV-negative ENKTL. Staging examinations, including whole-body computed tomography and positron emission tomography, revealed localized disease involving only the orbit and paranasal sinuses.

INTERVENTIONS: The patient was treated with etoposide, ifosfamide, cisplatin, and dexamethasone chemotherapy. After the first cycle, the patient developed severe neutropenia, and the chemotherapy dose was reduced by 40% for the second cycle. After 2 cycles of etoposide, ifosfamide, cisplatin, and dexamethasone chemotherapy, consolidation radiation therapy was recommended.

OUTCOMES: After 2 cycles of chemotherapy, positron emission tomography showed metabolic complete remission. At 3 months after the second cycle of chemotherapy, the skin defect had completely healed, and follow-up computed tomography showed disease remission.

LESSONS: Cutaneous manifestations of ENKTL can mimic benign inflammatory conditions such as cellulitis, leading to delayed diagnosis. Clinicians should maintain a high index of suspicion and perform early tissue biopsy for atypical ulcerative lesions in the periorbital and nasal areas, even in the absence of typical EBV positivity.