Acute lymphoblastic leukemia

Leukemic cells were positive for CD34, CD10, CD19, CD20, CD38.

Patient	Leukemia	Age/Sex	WBC 109/L	Karyotype	Outcome	References
1	B-precursor ALL	4/M	20	46,Y,der(X)t(X;8)(q28;q11.2),t(9;22)(q34;q11),t(8;14)(q11.2;q32),add(17)(p13)	CR; Relapsed after 23,5 mths	Kaleem et al., 2000
2	Common B ALL	19/M	17	46,Y,der(X)t(X;8)(q28;q11.2)	CR; Complex medullar and CNS extramedullary relapses after 10 mths and 13 mths; CR after BMT; Isolated post-transplant CNS relapse; died after 29 mths after diagnosis	Present case, 2016

Extremely rare karyotypic event in ALL; both ALL patients were males (aged 4 and 19 years).

Among the characteristic laboratory features were a low WBC at presentation. One of the two ALL patients had a few reddish skin nodules 5-7 mm in diameter, moderate hepatosplenomegaly. No patient had a mediastinal mass or central nervous system involvement at diagnosis, but one patient had CNS extramedullary relapses, including post-transplant.

Bone marrow are hypercellular with 54.4% lymphoblasts of L1 or L2 morphology. They were negative for myeloperoxidase, whereas most of them positive for PAS stain. Erythropoiesis and myelopoiesis were decreased. Erythropoiesis had signs of megaloblastosis. Megakaryocytopoiesis: hypolobular and polyploid megakaryocytes.

Histopathology of the skin nodules was remarkable for interstitially located groups of small- and middle-sized lymphoid blast-like cells, which were positive for TdT, PAX-5, CD20, CD10, negative for T-cell and myeloid markers and had a very high proliferation rate (Ki-67 index above 90 %). myc oncogene product was additionally assessed with immunohistochemistry (clone Y69). Over 90% of blast cells in the skin appeared to be positive for myc, although staining pattern was markedly heterogeneous. The brain tissue (at post-transplant relapse) contained a dense cellular infiltrate composed of middle-sized PAS-positive blasts with oval or round nuclei, containing 2-3 small nucleoli. Tumor cells were uniformly positive for TdT, CD19, PAX-5, and CD79a and had a very high Ki-67 proliferation index. myc oncogene product was demonstrated in over 85% of cells with heterogeneous staining pattern, compatible with indirect myc up-regulation.

Complete therapeutic data are available for one of the two ALL cases: treatment was started according to ALL-2009 protocol, containing Daunorubicin, Vincristine, and L-asparaginase. CNS prophylaxis therapy consisted of triple intrathecal treatments, whereas cranial irradiation was not used. The patient received allogeneic HSCT; conditioning regimen consisted of Melphalan and Fludarabine.

The risk associated with der(X)t(X;8)(q28;q11.2) is not well determined due to low number of cases.

Isolated derivative chromosome X was demonstrated in one ALL case (present case, 2016); in second one, the derivative chromosome X was combined with other recurrent chromosomal abnormalities (Kaleem et al, 2000).

Whole chromosome painting (WCP X, WCP8), mBAND 8 (Metasystems, Germany).

Found in association with t(9;22)(q34;q11), t(8;14)(q11.2;q32) and add(17)(p13) in one ALL case (Kaleem et al,2000).

No specific gene or protein are described.

The presence of partial 8q trisomy leads to gain of genetic material and consequently to amplification of genes possibly involved in the neoplastic process. MYC is one of the genes located on 8q which may be implicated in disease biology. Immunohistochemical staining for MYC protein showed positivity of >85% of leukemic cells, although with markedly heterogeneous staining pattern, compatible with indirect MYC up-regulation. The latter, in turn, could increase proliferative potential of leukemic cells as well as their resistance to chemotherapy. In several studies, trisomy 8 in ALL patients is considered to be indicative of poor prognosis (Garipidou et al).