Korean J Pathol.
2000 Aug;34(8):597-600.
Pigmented Mediastinal Paraganglioma: A case report
- Affiliations
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- 1Department of Pathology, College of Medicine, Hanyang University, Seoul 133-791, Korea.
Abstract
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Pigmented extraadrenal paraganglioma is an unusual neoplasm that has rarely
been reported in the literature. Based on histochemical staining or electron microscopy,
pigment has been classified as lipofuscin, neuromelanin or true melanin. We report a
case of pigmented extraadrenal paraganglioma in the posterior mediastinum of a
70-year-old woman. Histologically, the tumor had a characteristic organoid architecture
of "zellballen" pattern with rich delicate microvasculature. Tumor cells contained
numerous coarse brown-black pigment granules. Ultrastructurally, the tumor showed
abundant large electron-dense pigment granules that vary in size and shape and smaller
membrane-bound neurosecretory granules. The larger granules were consistent with
neuromelanin or lipofuscin. Histochemically, the pigment is most likely neuromelanin,
which is a waste product of catecholamine metabolism.