A melanotic paraganglioma occurred in a 57-year-old woman, located in
the left paravertebral space of the upper mediastinum. It was totally
resected. During a 5 year follow up period neither tumour reccurrence
nor metastasis were observed. Histological examination of the tumour r
evealed a paraganglioma with monomorphous chief cell like elements whi
ch were arranged in a ''zellballen'' pattern. Immunohistochemical resu
lts also were in accordance with the diagnosis since neuron-specific e
nolase, chromogranin and synaptophysin were found in tumour cells wher
eas keratin was not. Additionally, neurosecretory granules were found
in tumour cells during electron microscopy. A peculiar feature of the
tumour was its strong pigmentation due to melanin located within the t
umour cells and tumour associated melanophages. The simultaneous expre
ssion of functional properties of two different neural crest derived c
ells in one tumour stresses the close relationship between all neural
crest elements and is in accordance with the observation of other mela
notic, non-melanomatous tumours.