ACTH-Independent Cushing’s Syndrome Associated with Left Adrenocortical Oncocytoma of Uncertain Malignant Potential

Figure 2

Histopathological features and immunohistochemical findings: (a) encapsulated diffuse proliferation of large cells with focal capsular invasion. Inset: the cells show pleomorphic nuclei, prominent nucleoli, and wide eosinophilic and granular cytoplasm. (b) At higher magnification, capsular invasion is shown in detail (the arrow signs a thin fibrous capsule dividing the neoplasm from the cortex of the adrenal gland, while the thick arrow shows the focal infiltration of the adrenal parenchyma by the tumour). (c) The neoplastic cells resulted negative for chromogranin A (positive internal control: adrenal medulla). (d) The neoplastic cells resulted strongly and diffusely positive for inhibin A (internal control: adrenal cortex, mild and sparse positivity). (a, b) Haematoxylin-eosin stain. (c) Chromogranin A. (d) Inhibin A. Original magnification: (a) 40x, inset 200x; (b) 200x, (c, d) 100x.

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