A Case of Cushing’s Syndrome due to Ectopic Adrenocorticotropic Hormone Secretion from Esthesioneuroblastoma with Long Term Follow-Up after Resection

Figure 2

Histology staining of tumor.

(a) The skull base tumor, measuring 3.5 × 3.0 × 2.0 cm in aggregate. On hematoxylin and eosin (H&E) staining, the tumor is composed of small, round, uniform cells with stippled chromatin and distinct but inconspicuous nucleoli, growing in a diffuse and lobular pattern within a neurofibrillary matrix

(b) An immunohistochemical stain against synaptophysin, a neuroendocrine marker, shows diffuse, strong cytoplasmic positivity within tumor cells, confirming the neuroendocrine nature of this esthesioneuroblastoma

(c) Immunochemistry shows patchy expression of ACTH in the tumor cells (original magnification 400x)