Nasal-type NK/T-cell lymphoma: a case report.

Extranodal NK/T-cell lymphoma represents less than 1% of all lymphomas, but is more common in Asia and South America. We present a 67-year-old female with a 10-month history of four reddish-blue firm and painful nodules in the parietal region of the head, ranging in size from 1 to 5 cm. Two nodules were taken for biopsy, which showed atypical lymphoid cells with angiocentric growth pattern. The immunophenotype of the tumor cells was CD45RO +, CD56 +, CD3 + (epsilon chain), CD20-, consistent with the diagnosis of NK/T-cell lymphoma. NK/T-cell lymphomas are rare and the optimal treatment has not been clearly established.