Aggressive primary natural killer cell lymphoma of the caecum: a case report and literature review.

An unusual case of aggressive Stage IIE(B) primary natural killer cell lymphoma of the caecum is described in a 16-year old Chinese girl. The immunophenotype of the tumour cells was CD2+, CD3-, CD4-, CD5-, CD7+, CD8-, CD45RO+, CD45RA-, CD56+, CD57-. Southern blot analysis showed a normal germline arrangements of the T-cell antigen receptor and immuno-globulin heavy chain genes. This lymphoma pursued a highly aggressive clinical course, with the rapid development of an extensive local recurrence after an apparently complete resection and combination cytotoxic therapy. The patient died 7 months after diagnosis, despite receiving salvage treatment. Given the aggressiveness and poor prognosis in this biologically distinct primary gastrointestinal lymphoma, a more vigorous systemic therapy should be considered in addition to surgery.