FIGURE 2.

(A–D) Histologic Panel of phosphaturic mesenchymal tumor. At scanning magnification (2A. HE), the lesion appears as a mass forming proliferation with a grossly pushing border toward the adipose tissue of the chest wall. At higher magnification (2B. HE, 10×) the lesion consists of bland looking ovoid to spindle cells, with an unremarkable mitotic rate and absence of necrosis, growing in a diffuse fashion with irregularly intermixed hematic vascular structures. The detail (2C. HE, 40×) underlines the presence of the accumulation of hemosiderin laden macrophages (arrow) and of small foci of myxoid degeneration with finely granular calcifications (arrowhead). Immunohistochemical stain with anti‐FGF23 antibody (2D. 40×) resulted negative, as compared to the positive control (inset)