PATHOLOGY FINDINGS:
Morphology and Immunophenotypic Characterization:
The biopsy of this adrenal mass demonstrated histologically bland apparent adrenal cortical tissue (Figure 2A). Results of selected stains of the biopsy are shown in Table 1. EMA, inhibin, synaptophysin, and vimentin are shown in Figures 2B, 2C, 2D and 2E, respectively. The resection specimen consisted of a lobulated yellow soft tissue mass, 20 x 15 x 6 cm. Cut section revealed a 12 x 6.2 x 5 cm well demarcated, finely lobular tan-yellow mass. Large areas of hemorrhage and necrosis were seen (Figure 3A). A rim of normal appearing golden adrenal cortex was identified near one end of the specimen (Figure 3B). Microscopic examination showed this neoplasm to consist predominantly of clear cells arranged in trabecular and nested patterns (Figure 4A). The nuclei of the tumor cells displayed mild pleomorphism with slightly open chromatin and occasional small nucleoli (Figure 4B). Mitoses were not identified. In some sections, adjacent to the neoplasm, normal appearing adrenal gland was seen (Figure 4C). The tumor appeared to invade the adrenal tissue (Figure 4D). A battery of immunohistochemical stains was performed initially on a section containing tumor only (Table 2). Focal and scattered immunoreactivity was seen with cytokeratin AE1/3, CAM5.2, synaptophysin, and EMA (Figures 4E, 4F, 4G and 4H, respectively). More numerous positive cells were seen with inhibin alpha and CD10 (Figures 4I and 4J). Vimentin stain demonstrated strong focal immunoreactivity (Figure 4K) and highlighted areas within the neoplasm with tubular configuration (Figure 4L). Immunohistochemical stain for RCC was weakly and focally positive (Figures 4M [upper left] and 4N [lower right]). This profile did not securely differentiate between a primary renal cell carcinoma and adrenal cortical carcinoma. This same battery of immunohistochemical stains was also performed on sections of the large neoplasm adjacent to grossly normal appearing adrenal gland (Table 3). Distinctions in the staining pattern are more readily apparent between these two adjacent tissues. CD10 and RCC (Figures 5A and 5B, respectively) show positivity within the tumor while inhibin and synaptophysin (Figures 5C and 5D, respectively) show positivity within the adrenal gland portion. Ki67 demonstrated increased nuclear staining within the neoplasm compared to the adjacent adrenal gland (Figures 5E and 5F, respectively). However, the overall proliferative index for this neoplasm was less than 5 percent.
Stain |
Biopsy |
EMA |
Focally positive |
Inhibin |
Positive |
Synaptophysin |
Negative |
Vimentin |
Diffusely positive |
Table 2. Immunohistochemical Staining Profile of Suprarenal Mass
Stain |
Tumor |
Cytokeratin AE1/3 |
Focally weakly positive |
CAM5.2 |
Scattered positive cells |
EMA |
Scattered positive cells |
Vimentin |
Scattered weakly positive* |
Inhibin |
Scattered positive cells |
CD10 |
Scattered positive cells |
RCC |
Focally positive |
Synaptophysin |
Rare scattered cells with granular staining |
Ki67 |
Scattered positive cells |
P53 |
negative |
Table 3. Immunohistochemical Staining Profile of Suprarenal Mass and Adjacent Adrenal Gland
Stain |
Neoplasm |
Adjacent Adrenal Gland |
Cytokeratin AE1/3 |
Negative |
Negative |
CAM5.2 |
Focally positive |
Negative |
EMA |
Focally positive |
Diffusely positive |
Vimentin |
Scattered weak positive |
Diffusely positive |
Inhibin |
Focally weakly positive |
Strong diffusely positive |
CD10 |
Focally positive |
Negative |
RCC |
Focally positive |
Negative |
Synaptophysin |
Negative |
Positive |
Ki67 |
Focally moderately numerous positive cells |
Scattered positive cells |