Enfermedad de Castleman multicéntrica en pacientes HIV positivos. Reporte de dos casos y revisión de la literatura / Multicentric Astleman disease in HIV positive patients. Two cases. Report and literature review

La enfermedad de Castleman (EC) es un proceso linfoproliferativo poco frecuente que se caracteriza por hiperplasia de los ganglios linfáticos. Existen dos variedades histológicas bien diferenciadas la hialino-vascular y la plasmocelular, que a su vez pueden ser localizadas o multicéntricas. La forma hialino-vascular suele ser asintomática y localizada en mediastino mientras que la plasmocelular se presenta frecuentemente con signo-sintomatología sistémica y suele ser difusa o multicéntrica. En el contexto de la enfermedad debida al virus de la inmunodeficiencia humana (VIH), la EC se asocia en su patogenia a la infección por el herpes virus humano tipo-8 (HHV-8). La mayoría de los casos corresponden a la variante hialino-vascular (80/90%) en tanto un pequeño porcentaje (10/20%) son de la variante plasmocelular. En algunos pacientes, el patrón histopatológico puede ser mixto. Se describen dos casos de enfermedad de Castleman multicéntrica HHV8- positiva en pacientes con enfermedad HIV/SIDA.

Castleman's disease (CD), is a rare hematological condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. This is considered as a distinct type of lymphoproliferative disorder associated with inflammatory symptoms. In the context of human immunodeficiency virus (HIV) infection, CD is associated with human herpesvirus-8 (HHV8) infection. Most cases of CD represent either the hyaline vascular variant (80­90% of cases) or the plasma cell variant (10­20%); a small percentage present with a mixed histologic appearance. Two cases of Castleman's disease associated with HHV-8 and HIV/AIDS infection are described

Mutational profile and EBV strains of extranodal NK/T-cell lymphoma, nasal type in Latin America.

Extranodal NK/T-cell lymphoma (ENKTL) is an Epstein-Barr virus (EBV) associated lymphoma, prevalent in Asia and Latin America. Studies in Asian cohorts have identified some recurrent gene mutations in ENKTL; however, the mutational landscape of ENKTL in Latin America is unknown. In this study, we investigated the mutational profile and EBV strains of 71 ENKTL cases from Latin America (42 from Mexico, 17 from Peru, and 12 from Argentina) and compared it with Asian cohorts. The mutational analysis was performed by next generation sequencing (NGS) using an Ion AmpliSeq™ custom panel covering for the most frequently mutated genes identified in ENKTL. STAT3 was the most frequent mutated gene (16 cases: 23%), followed by MSN (10 cases; 14%), BCOR (9 cases; 13%), DDX3X (6 cases; 8%), TP53 (6 cases; 8%), MGA (3 cases; 4%), JAK3 (2 cases; 3%), and STAT5B (1 case; 1%). Mutations in STAT3, BCOR, and DDX3X were nearly mutually exclusive, suggesting different molecular pathways involved in the pathogenesis of ENKTL; whereas mutations in MGA, MSN, and TP53 were concomitant with other mutations. Most cases (75%) carried Type A EBV without the 30-bp LMP1 gene deletion. The overall survival was significantly associated with serum LDH level, Eastern Cooperative Oncology Group (ECOG) performance status, International Prognostic Index (IPI) score, and therapy (p < 0.05), but not associated with any mutation, EBV strain or deletion in EBV LMP1 gene. In conclusion, mutational analysis of ENKTL from Latin America reveals frequent gene mutations leading to activation of the JAK-STAT pathway (25%), mostly STAT3. Compared to Asian cohorts, BCOR, DDX3X and TP53 mutations were also identified but with different frequencies. None of these mutations were associated with prognosis.