Extranodal NK/T-cell lymphoma mimicking cellulitis.

NK/T-cell lymphoma is difficult to diagnose because there is no characteristic cytology to help the diagnosis in tissue sections, particularly when there is polymorphic cellular infiltration in the early stage of the disease. However, the nasal type of extranodal NK/T-cell lymphoma has a characteristic histologic pattern, which is angiocentric, angioinvasive and angiodestructive. Therefore, many cases of this tumor may show extensive necrosis that mimics infectious process. Furthermore, because the immunosuppressive status of these patients, they may, in fact, have superimposed infections. We are reporting a case that presented as cellulitis and only after careful examination with immunohistochemistry that a correct diagnosis of extranodal NK/T-cell lymphoma, nasal type, was established. Since this lymphoma is incurable and immunophenotyping is instrumental for the diagnosis and prediction of the prognosis, a high index of suspicion for this tumor is needed when an angiocentric lesion is found in the midline of the head and neck region, and a thorough immunohistological study should always be conducted in these cases.