Fig. 2

A–D Before the first operation, enhanced MRI of the orbit. Bilateral retrobulbar lesions filled with equal T1 and T2 signals and uneven enhancement on the enhanced scan. The mass surrounding the bilateral optic nerve and bilateral eyeball compression protrusion is more obvious on the left than on the right. E, F A year later, CT of the orbit revealed soft tissue density filling behind the bilateral intraorbital bulbs. G, H CT demonstrates pericardial thickening and effusion and bilateral hydronephrosis with peri-nephric fat stranding. I Positive cytoplasmic CD68 immunostaining of tumor cells (CD68, original magnification × 400). J Negative cytoplasmic S-100 immunostaining of tumor cells (S-100, original magnification × 400). K Negative cytoplasmic Langerin immunostaining of tumor cells (Langerin, original magnification × 400). L Negative cytoplasmic CD1a immunostaining of tumor cells (CD1a, original magnification × 400) M Negative cytoplasmic ALK immunostaining of tumor cells (ALK, original magnification × 400). N Positive cytoplasmic CD138 immunostaining of tumor cells (CD138, original magnification × 400). O Positive cytoplasmic IgG4 immunostaining of tumor cells (IgG4, original magnification × 400,  > 100 cells/HPF). P Ki67 immunostaining demonstrating that approximately 10–20% of tumor cells showed strong nuclear immunoreactivity (Ki67, original magnification × 400)