A Solitary Fibrous Tumor with Giant Cells in the Lacrimal Gland: A Case Study
A 39-year-old man presented with a painless left upper eyelid mass that had presented three months previous. An orbital computed tomography scan showed that a 1.1 cm-sized, well-defined nodule with an eccentric nodular enhancement, and an internal low attenuation area was present in the left lacrimal gland (). An en-block excision was performed under the impression that this mass was a pleomorphic adenoma. The excised mass was well-demarcated, ovoid, and firm, with measurements of 1.5×1.3×0.7 cm. The cut surface had a whitish tan hue and was fibrotic with a multifocal hemorrhage (). Histopathological examination showed a spindle cell proliferative lesion that was surrounded by the lacrimal gland parenchyma (). The cellularity was variable and presented as either a patternless or a storiform pattern (). Collagenized stroma and dense collagen nodules were found around dilated vessels, and perivascular hyalinization was also observed (). The spindle cells had scant cytoplasm and short, oval spindle nuclei with fine chromatin and inconspicuous nucleoli. Multinucleated giant cells were either observed in the periphery of the mass giant cells or were not identified (). Mitotic activity was low (only observed in two of ten high magnification fields). Immunohistochemistry demonstrated that the spindle cells were strongly positive, and the multinucleated cell cytoplasm was focally positive for CD34 and CD99 (). Smooth muscle actin and S-100 protein were not detected. The diagnosis of a SFT was made on the basis of the histological findings, which showed that the mass lacked the typical components and immunoprofiles of giant angiofibromas.