Extranodal NK/T-cell lymphoma, nasal type: study of clinicopathologic and prognosis factors in a series of 78 cases from Peru.

It is well known that extranodal NK/T-cell lymphoma (NK/TCL) nasal type clusters in Asian countries. A large series of 78 cases of nasal NK/TCL from Peru is analyzed in the present study. Two histologic groups 1 (monomorphic) and 2 (polymorphic), were segregated according to the proportion of large cells (above and below 30%, respectively). Catalyzed signal amplification technique was performed for enhancement of immunohistochemistry reactivities. Epstein-Barr virus (EBV) sequences and types were investigated using polymerase chain reaction. Clinical characteristics, stage, outcome, and response to treatment were evaluated in both groups. Fourteen cases (18%) and 64 cases (82%) corresponded to groups 1 and 2, respectively. Except for nasal obstruction, more common in group 2, all other symptoms were similar in both groups. Local extension and staging were also comparable. Both groups showed CD3c+ CD2+ CD56+ CD3s- CD20- immunophenotype. All cases were positive for EBV. In this series type-2 EBV was found more frequent than type-1 EBV, contrarily to that observed in Asian series. However, about one-third of cases simultaneously harbored both viral types. Both groups received an average of 50-Gy dose of radiation therapy (RT), with or without chemotherapy. Complete therapeutic response was achieved in 89% of group 1 and in 74% of group 2, but this difference was not statistically significant. There were no significant differences between the groups regarding disease-free survival, failure-free survival, relapse, and overall survival. The overall survival, in both groups, was longer for patients treated with RT alone compared with those treated with combined RT therapy and chemotherapy. The present study has shown that dividing nasal NK/TCL in monomorphic and polymorphic variants, according to frequency of large cells, does not correlate with clinical and prognostic factors.

Primary meningeal Epstein-Barr virus-related leiomyosarcoma in a man infected with human immunodeficiency virus: review of literature, emphasizing the differential diagnosis and pathogenesis.

We describe the clinical, radiologic, surgical, and pathologic findings of a 29-year-old Peruvian human immunodeficiency virus-infected man with a primary parasellar meningeal leiomyosarcoma involving the left lesser esphenoidal wing and the cavernous sinus. Over a period of 13 months, he developed headache, vomiting, insomnia, and diplopia. Magnetic resonance imaging revealed a left parasellar extra-axial mass that was isointense in T1, hypointense in T2, and gadolinium-enhanced. The patient underwent subtotal resection of the tumor. The neoplasm was composed of spindle cells with smooth-muscle features. It showed moderate atypia, inconspicuous nucleoli, and scanty mitosis. No tumor necrosis was detected. The immunohistochemistry revealed strong positivity for vimentin, desmin, and smooth-muscle alpha-actin. A low-grade leiomyosarcoma was diagnosed. The in situ hybridization showed positive nuclear reactivity for Epstein-Barr virus-encoded RNA. The immunohistochemistry was negative for Epstein-Barr virus latent membrane protein 1. The main differential diagnosis of primary meningeal smooth-muscle tumors includes meningioma and peripheral nerve sheath tumors. Epstein-Barr virus has been demonstrated in most smooth-muscle tumors associated with acquired immune deficiency syndrome (AIDS). Primary meningeal smooth-muscle tumors, exceedingly rare neoplasms, remarkably affect young adults with AIDS. Comparatively, most AIDS-related visceral (nonmeningeal) smooth-muscle tumors have been reported in children. The permissiveness and tumorigenesis associated with Epstein-Barr virus may depend on the age of human immunodeficiency virus infection.