[798] The Utility of Immunohistochemical Markers in Differentiating between Recurrent Clear Cell Renal Cell Carcinoma, Retroperitoneal Paraganglioma and Adrenal Cortical Lesions with Limited Biopsy Material
J Lapinski, L Chen, M Zhou. The Cleveland Clinic Foundation, Cleveland, OH
Background: Retroperitoneal recurrence of clear cell renal cell carcinoma (CCRCC) after surgical resection is usually investigated by needle biopsy. However, CCRCC can be difficult to distinguish from adrenal cortical lesions or paragangliomas based on morphologic examination of limited biopsy material. This study explored the diagnostic utility of a panel of immunohistochemical markers in dealing with this differential diagnosis.
Design: To stimulate the scarcity of biopsy material, a tissue microarray (TMA) with 1 mm tissue cores was constructed to include 21 cases of CCRCC, 19 normal adrenal cortex, and 15 retroperitoneal or mediastinal paragangliomas. Triplicate cores were used for each case. The TMA was then immunostained with epithelial markers (AE1/3, CAM 5.2, EMA), RCC markers (CD10, CA9, RCC antigen), adrenal cortical markers (calretinin, melan-A), and neuroendocrine markers (synaptophysin, chromogranin, CD56, NSE). The staining intensity and % of positive cells were recorded for each case.
Results: The % of positive cases for each marker is shown in the table.
| Immunohistochemical markers | Number (%) positive cases | | | CCRCC | Adrenal cortex | Paraganglioma | | Epithelial | AE 1/3 | 12/21 (57.1%) | 1/19 (5.3%) | 0/15 (0%) | | CAM 5.2 | 17/21 (81.0%) | 17/19 (89.5%) | 1/15 (6.7%) | | EMA | 14/21 (66.7%) | 0/19 (0%) | 0/15 (0%) | | RCC | RCC antigen | 16/21 (76.2%) | 0/19 (0%) | 0/15 (0%) | | CA9 | 18/21 (85.7%) | 0/19 (0%) | 1/15 (6.7%) | | CD10 | 21/21 (100%) | 1/19 (5.3%) | 0/15 (0%) | | Adrenal cortical | Calretinin | 0/21 (0%) | 19/19 (100%) | 5/15 (33.3%) | | melan-A | 4/21 (19.0%) | 18/19 (94.7%) | 5/15 (33.3%) | | Neuroendocrine | Synaptophysin | 0/21 (0%) | 17/19 (89.5%) | 15/15 (100%) | | Chromogranin | 4/21 (19.0%) | 8/19 (42.1%) | 6/15 (40%) | | CD56 | 1/21 (4.8%) | 19/19 (94.7%) | 15/15 (93.3%) | | NSE | 21/21 (100%) | 18/19 (94.7%) | 15/15 (100%) |
Conclusions: Although immunohistochemical stains, including epithelial and adrenal cortical markers, are extremely useful, and in some cases are necessary, to differentiate CCRCC from adrenal cortical lesions and retroperitoneal paraganglioma, CAM5.2 and melan-A should not be used for this purpose as there is significant overlap in the staining patterns of these 3 lesions. In addition, immunohistochemical stains are not useful in differentiation between adrenal cortical lesions and paragangliomas.
Category: Genitourinary (including renal tumors)
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 137, Tuesday Afternoon
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