Benign but locally aggressive tumor.

Occurs mainly in vertebrae and flat bones. Multiple involvement is frequent.

May involve the arrest of maturation of the osteoblasts caused by USP6 overexpression and dysregulation of autocrine BMP (bone morphology protein) signaling (Lau et al., 2010).

Usually seen in patients aged 10-20 years; represents about 5% of primary bone tumours; slightly more frequent in female patients.

Forms a spongy hemorrhagic mass; symptoms are pain, swelling, pathological fractures. About eleven cases to date have been described with a t(16;17)(q22;p13), 7 female patients aged 5, 7, 13, 13, 14, 15, and 17 years, and 4 male patients aged 10, 12, 13, and 30 years (Panoutsakopoulos et al., 1999; Herens et al., 2001; Wyatt-Ashmead et al., 2001; Althof et al., 2004; Oliveira et al., 2004).

Surgical curetage.

Recurrence occurs in one fourth of cases.

In 8 of the 11 cases, the t(16;17)(q22;p13) was the sole anomaly.

CDH11 (cadherin 11)

16q21

Cell-cell adhesion molecule that mediates adhesion by Ca2+-dependent interactions. Its intracellular domain is anchored to the actin cytoskeleton through alpha and beta-catenin. Role in maintaining tissue architecture and cell polarity, limiting cell movement and proliferation. CDH11 antagonizes Wnt/beta-catenin signaling pathway, induces apoptosis, and regulates epithelial-mesenchymal transition (Li et al., 2011). CDH11 is involved in various cancers. Tumor suppressor function.

USP6 (ubiquitin specific protease 6 (Tre-2 oncogene))

17p13.2

USP6, also called TRE17/ubiquitin-specific protease 6 (USP6), is a deubiquitinase. It is the first de-ubiquitinating enzyme to activate NF-KB, and requires both catalytic subunits of IKK (IKKalpha and IKKbeta) (Pringle et al., 2011).

5 CDH11 - 3 USP6

The promotor of CDH11 is juxtaposed to the entire sequence of USP6.