RESUMO
Acute promyelocytic leukemia (APL) is characterized by reciprocal translocation t(15;17)(q22;q21) and has a favorable prognosis upon immediate recognition and treatment. However, rare cases of APL show a cryptic insertion of retinoic acid receptor alpha (RARA) gene into promyelocytic leukemia (PML) gene which is negative both by fluorescence in situ hybridization (FISH) and conventional cytogenetics (CC). Morphology, cytochemistry and flow cytometry play a key role in early identification of such cases. Polymerase chain reaction (PCR) remains the most efficient diagnostic modality for detection of cryptic APL and other variants. It is important to identify these cases as they show beneficial response to retinoids and favourable prognosis. We herein present a rare case of cryptic APL negative by FISH and conventional cytogenetics but positive for PML-RARA by PCR.
Assuntos
Antígeno CD56/genética , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patologia , Antígeno CD56/biossíntese , Análise Citogenética , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Hibridização in Situ Fluorescente , Leucemia Promielocítica Aguda/diagnóstico , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Proteína da Leucemia Promielocítica/genética , Receptor alfa de Ácido Retinoico/genéticaRESUMO
BACKGROUND: Plasma cell leukemia (PCL) is a rare and aggressive plasma cell neoplasm. In PCL, clonal plasma cells comprise ≥20% of the peripheral blood (PB) leukocytes and/or the absolute clonal PB plasma cell count is ≥2×10(9)/L. Primary PCL (PPCL) originates de novo, whereas, secondary PCL (SPCL) evolves from pre-existing multiple myeloma. METHODS: Clinicohematological features, immunophenotypic profile, and survival of PCL patients were analyzed retrospectively. RESULTS: Between January 2007 and December 2014, ten PPCL and four SPCL patients were investigated (8 PPCLs and 3 SPCLs had complete clinical data). All were North Indians, sharing common geography and ethnicity. Our cohort showed less frequent renal failure, more frequent hepatomegaly, and non-secretory type disease. In contrast to western literature, flow cytometric immunophenotyping of our cohort revealed altered expression of CD138 (67%), CD56 (33%), and CD20 (0%). With novel therapeutic agents, these PPCL patients had a median overall survival of 15 months. CONCLUSION: We highlight that our PPCL patients from North India had distinct clinicohematological and immunophenotypic profiles. The significance of our findings must be tested in a larger patient cohort and must be supported by molecular and cytogenetic investigations to unmask possible significant effects on pathogenesis.
