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Image Description

Granular cell tumors are composed of round, polygonal, or spindle-shaped cells (as seen here) with nuclei ranging from small, hyperchromatic, pyknotic to large vesicular nuclei with punctate nucleoli. Occasional nuclei may show intranuclear pseudoinclusions or degenerative-type atypia.

The cytoplasm is eosinophilic with fine to coarse granules as well as large round droplets that are PAS-positive, diastase-resistant. These granules represent phagolysosomes accumulated in the cytoplasm. Ultrastructurally, they appear as membrane-bound vacuoles containing myelin figures, fragmented rough endoplasmic reticulum, and mitochondria. In addition, there is a second population of cells with angulated bodies. There is replicated basal lamina material around the granular cells.

Image 15 of 27