Bronchial Carcinoid with S-100 Positive Sustentacular Cells

Abstract

A case of double bronchial typical carcinoid of the central type, with a nodal metastasis and paraneoplastic Cushing syndrome is reported. The case is remarkable because both the primary tumors and nodal metastasis were composed of a double cell population: one was arranged in nests, was argyrophilic, immunostained with PHE-5 monoclonal antibody, and contained neurosecretory granules; the other one was neither argyrophilic nor PHE-5-immunoreactive, but was strongly immunoreactive for S-100 protein, had a stellate morphology and was at the periphery of the nests of the other cells. The S-100 immunoreactive cells were regarded as a sort of "sustentacular" or "satellite" cells, which are themselves neoplastic. Bronchial carcinoids with S-100 positive cells, although strictly related with other bronchial carcinoids, may in fact represent a group of tumors with different histogenesis and/or differentiative pattern. More work should be done to elucidate whether there is any relevant clinical difference between bronchial carcinoids with or without S-100 reactive cells.

Sustentacular cells in pulmonary neuroendocrine tumours

“…[15][16][17][18] Studies such as these, and others, 6,[19][20][21] have revealed S100-positive sustentacular cells to be present in the great majority of appendiceal carcinoids, and a significant proportion of such tumours arising at other locations in the gastrointestinal tract also appear to contain them. [5][6][7] In 1982, Nakajima et al 22 described S100-positive sustentacular cells in a bronchial carcinoid tumour and a series of subsequent studies has confirmed the observation, 8,19,[23][24][25] a sustentacular cell component being reported in up to 55% of tumours studied. The present investigation revealed sustentacular cells to be present in a higher proportion than this.…”

Sox10‐positive sustentacular cells in neuroendocrine carcinoma of the lung

“…We also found that the highest number of Sox10‐positive cells in primary sites correlated closely with that in the metastatic lymph nodes. The presence of sustentacular cells in a metastatic site has been reported previously in one case each of bronchial carcinoid tumour 15 and malignant pheochromocytoma 9 . These results indicate that sustentacular cells do not maintain the structure of tumour nests.…”

“…Using Sox10 labelling, we found sustentacular cells in TC (66.7%) and AC (58.3%) tumours but not in LCNEC or SCLC. In previous studies using immunostaining with the less‐specific S100 protein, bronchial carcinoid tumours have been found to contain from 18% to 82% sustentacular cells 3,6,11–17 . To our knowledge, there has been only one previous report that used Sox10 labelling to test for the presence of sustentacular cells in AC and TC tumours.…”

“…The exact mechanisms of sustentacular cells are unknown, but they probably play a role in maintaining architectural integrity. However, they are also found in a proportion of some neoplasms such as extra‐adrenal paragangliomas, 4–6 pheochromocytomas 7–10 and carcinoid tumours 2,3,6,11–18 …”