A group of lung neuroendocrine (NE)
neoplasms are investigated in view of the possible
presence of S-100 protein immunoreactivity in their cells.
The selected tumours were classified according to
Gould et al. (1983a) and Mosca et al. (1985). They
comprise 5 carcinoids, 3 neuroendocrine carcinomas of
the well-differentiated type, or peripheral carcinoids, 5
neuroendocrine carcinomas of the intermediate cell type,
or intermediate-cell, poorly differentiated carcinomas, 3
neuroendocrine carcinomas of the microcytoma type,
or small cell carcinomas-SCC and a nodal metastasis of
microcytoma.
All but 2 tumours were immunoreactive for neuron
specific enolase (NSE).
Few S-100 immunoreactive cells were detected in 4
out of 5 carcinoids, in 1 out of 3 peripheral carcinoids, in
4 out of 5 poorly differentiated carcinomas and in the 3
microcytomas examined. No S-100 positive cells were
found in the SCC's nodal metastasis.
The S-100 immunolabelled cells can be interpreted as
dendritic reticulum cells migrating through the tumours.
However, in one case of typical carcinoid, abundant
S-100 positive cells were detected: their stellate
morphology and their intimate relation with neoplastic
cells suggest that they are part of the neoplasia as a sort
of satellite cell