Bronchial carcinoid with S-100 positive sustentacular cells

Area of Science:

• Pulmonology
• Oncology
• Surgical Pathology

Background:

• Bronchial carcinoid tumors are neuroendocrine neoplasms of the lung.
• Typical carcinoids represent the most common subtype and generally have a good prognosis.
• Paraneoplastic syndromes, such as Cushing syndrome, can occur secondary to bronchial carcinoid tumors.

Purpose of the Study:

• To report a unique case of a double bronchial carcinoid tumor.
• To investigate the histopathological features of the tumor, including the presence of S-100 positive cells.
• To discuss the potential implications of these findings for tumor classification and clinical management.

Main Methods:

• Histopathological examination of the primary tumor and nodal metastasis.
• Immunohistochemical staining for neuroendocrine markers (argyrophilia, PHE-5) and S-100 protein.
• Electron microscopy to identify neurosecretory granules.

Main Results:

• The bronchial carcinoid tumor exhibited a double cell population: argyrophilic, PHE-5 positive cells with neurosecretory granules, and S-100 positive stellate cells.
• The S-100 positive cells were located at the periphery of the nests of the other cells, suggesting a sustentacular or satellite role.
• The tumor presented with nodal metastasis and paraneoplastic Cushing syndrome.

Conclusions:

• Bronchial carcinoids with S-100 positive cells may represent a distinct subgroup with potentially different histogenesis or differentiation.
• The S-100 positive cells are likely neoplastic and may function as sustentacular cells.
• Further research is needed to determine the clinical significance and prognostic implications of S-100 positive cells in bronchial carcinoids.