PMC5727653_01
Composite figure illustrating imaging, surgical, histologic, and ultrastructural findings. (a) Sagittal CT scan shows a large ovoid mass (arrow) abutting the liver and the superior pole of the right kidney. (b) Surgical resection specimen highlights the bright yellow tumor parenchyma as well as a portion of the patient's residual adrenal gland (arrows). (c) Microscopic examination of adrenal oncocytic neoplasm composed of large cells with abundant pink granular cytoplasm and irregular nuclei with prominent nucleoli (H&E, 20x). The insert highlights the presence of areas displaying marked nuclear pleomorphism and atypia (H&E, 40x). (d) Transmission electron microscopy illustrating a tumor cell at the center of the image with a large centrally located oval nucleus and abundant mitochondria occupying most of the cytoplasm. H&E: hematoxylin and eosin.
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As part of her initial workup, the patient had an abdominal CT scan that revealed a 15 cm right adrenal mass (Figure 1(a)). The right adrenal gland was found adjacent to the mass (Figure 1(b)). Microscopic examination of the tumor after formalin fixation demonstrated a neoplasm composed of large oncocytic cells (Figure 1(c)) with focal areas of nuclear pleomorphism (Figure 1(c), insert). The presence of increased intracytoplasmic mitochondria was confirmed by electron microscopy (Figure 1(d)).
Composite figure illustrating TSPO protein expression findings. (a) Expression of TSPO by immunofluorescence in normal adrenal gland demonstrates diffuse immunofluorescence for TSPO protein, particularly in the zona glomerulosa (IF, 10x). (b) Diffuse loss of TSPO expression assessed by immunofluorescence in adrenal oncocytic tumor cells (IF, 10x). Polyacrylamide gels of the experiments performed in duplicate including normal adrenal cortex from the patient as internal control and tumor, normalized to beta-actin for cytosolic extracts (c) and lamin a/c for nuclear extracts (d) as housekeeping genes, show a noticeable decrease in the concentration of TSPO in tumor compared to the patient's normal adrenal gland. Western blot semiquantification bar graphs demonstrate 72.4 and 72.8% decrease in cytosolic and 77.1 and 76.8% decrease in nuclear TSPO expression as compared to respective controls. IF: immunofluorescence.
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fig2
M confocal microscope (Carl Zeiss, Peabody, MA, USA). Multiple images captured from tumor cells and normal adrenal gland showed strong immunofluorescence positivity in the normal adjacent adrenal gland (Figure 2(a)) and significant loss of TSPO expression in the tumor cells (Figure 2(b)). As illustrated in Figures 2(a) and 2(b) (cytosolic fraction) and Figures 2(c) and 2(d) (nuclear fraction), the representative semiquantitative immunoblots from two different tumor sections show a significant decrease in TSPO expression in the tumor sample of 72.4 and 72.8% decrease in the cytosol and 77.1 and 76.8% decrease in the nuclear fraction as compared to respective controls (p = 0.03).