t(4;22)(q12;q11.2) involving presumptive platelet-derived growth factor receptor A and break cluster region in a patient with mixed phenotype acute leukemia

A rare cause of persistent leukocytosis with massive splenomegaly: Myeloid neoplasm with BCR-PDGFRA rearrangement-Case report and literature review

RATIONALE

Persistent leukocytosis with megalosplenia is a common manifestation among patients with myeloproliferative neoplasm (MPN), especially for chronic myeloid leukemia (CML) patients. Here, we report a rare case of myeloid neoplasm with BCR-PDGFRA rearrangement characterized by obvious elevation of leukocyte count and megalosplenia.

PATIENT CONCERNS

A 32-year-old man presented with persistent leukocytosis and megalosplenia.

DIAGNOSIS

This patient was characterized by increased leukocyte count and megalosplenia, and was clinically diagnosed as CML. However, the BCR/ABL fusion gene of the patient was negative, which did not support CML. Moreover, the results of the karyotype showed 46, XY, t(4;22)(q12;q11) and RT-PCR + Sanger detection showed positive PDGFA/BCR. Accordingly, the diagnosis of myeloid neoplasm with BCR-PDGFA rearrangement was confirmed.

INTERVENTIONS

This patient was initially received imatinib (400 mg) orally once a day, and the dosage was adjusted to 100 mg owing to suffering from grade IV bone marrow suppression.

OUTCOMES

Hematological remission was achieved after 2 weeks, the best treatment response was achieved after 3 months, and the main molecular biological response was achieved after 12 months.

LESSON

This case suggests that rare PDGFA fusion genes screening for patients comorbid with leukocytosis and megalosplenia is necessary to avoid misdiagnosis. Unlike other rearrangements of PDGFRA, the clinical manifestations of BCR-PDGFRA rearrangement are resembling CML without eosinophilia increase.

A Bioinformatic Pipeline Places STAT5A as a miR-650 Target in Poorly Differentiated Aggressive Breast Cancer

Breast cancer (BRCA) is a leading cause of mortality among women. Tumors often acquire aggressive features through genomic aberrations affecting cellular programs, e.g., the epithelial to mesenchymal transition (EMT). EMT facilitates metastasis leading to poor prognosis. We previously observed a correlation between an amplification of miR-650 (Amp-650) and EMT features in BRCA samples isolated from Mexican patients. In this study, we explored the cBioportal database aiming to extend that observation and better understand the importance of Amp-650 for BRCA aggressiveness. We found that Amp-650 is more frequent in aggressive molecular subtypes of BRCA, as well as in high grade poorly differentiated tumors, which we confirmed in an external miRNA expression database. We performed differential expression analysis on samples harboring Amp-650, taking advantage of gene target prediction tools and tumor suppressor gene databases to mine several hundreds of differentially underexpressed genes. We observed STAT5A as a likely putative target gene for miR-650 in aggressive poorly differentiated BRCA. Samples with both Amp-650 and low expression of STAT5A had less overall survival than samples with either or none of the alterations. No target gene has been described for miR-650 in BRCA, thus, this bioinformatic study provides valuable information that should be corroborated experimentally.

Complete and long-lasting cytologic and molecular remission of FIP1L1-PDGFRA-positive acute eosinophil myeloid leukaemia, treated with low-dose imatinib monotherapy

Myeloproliferative neoplasms associated with FIP1L1-PDGFR rearrangements represent a rare subset of myeloid and lymphoid malignancies, characterised by the presence of eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1 genes. The fusion product of such genes is a tyrosine kinase oncoprotein sensitive to imatinib, which to date results to be the standard of care for FIP1L1-PDGFRA-positive chronic myeloproliferative disorders with eosinophilia. However, the coexistence of FIP1L1-PDGFRA rearrangement associated with acute myeloid leukaemia is extremely rare. Here, we report a rare case of FIP1L1-PDGFRA-positive acute myeloid leukaemia, with marked peripheral blood and bone marrow eosinophilia, treated with low dose of imatinib monotherapy, achieving a rapid and long-lasting complete cytologic and molecular remission, without need for intensive chemotherapy.