Arumugam Jhansi Rani, Karthik Bommannan B K, Kalaiyarasi Jayachandran Perumal, Sundersingh Shirley
Department of Oncopathology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, India.
Department of Medical Oncology, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu, India.
Indian J Pathol Microbiol. 2021 Apr-Jun;64(2):406-409. doi: 10.4103/IJPM.IJPM_409_20.
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.
急性早幼粒细胞白血病（APL）的特征是15号和17号染色体相互易位t(15;17)(q22;q21)，一旦得到及时诊断和治疗，其预后良好。然而，罕见的APL病例显示维甲酸受体α（RARA）基因隐匿性插入早幼粒细胞白血病（PML）基因，荧光原位杂交（FISH）和传统细胞遗传学（CC）检测均为阴性。形态学、细胞化学和流式细胞术在这类病例的早期识别中起关键作用。聚合酶链反应（PCR）仍然是检测隐匿性APL及其他变异型最有效的诊断方法。识别这些病例很重要，因为它们对维甲酸治疗有良好反应且预后良好。我们在此报告一例罕见的隐匿性APL病例，FISH和传统细胞遗传学检测均为阴性，但PCR检测PML-RARA为阳性。
