Clinical and Histopathological Study of Pheochromocytoma Arising in the Adrenal Gland / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: The diagnosis and prognosis of malignant pheochromocytoma are important. Other than distant metastasis, the pathology is insufficient to diagnose malignant versus benign pheochromocytoma. METHODS: We analyzed 33 pheochromocytoma cases using the histological grade on the Thompson and Kimura scales. We compared the Thompson and Kimura scores with the degree of immunohistochemical staining for Ki-67 and heat shock protein 90 (Hsp90). RESULTS: The most frequent symptom was hypertension (17 cases; 51.5%) and four patients had accompanying tumors: one case each of multiple endocrine neoplasm, papillary carcinoma of the thyroid, gastric adenocarcinoma, and neurofibroma. The mean Thompson score was 3.67 in benign pheochromocytoma and 10 in malignant pheochromocytoma, and the Kimura score was 2.17 and 5, respectively. The average immunohistochemical staining for Ki-67 was 5.77 and 10.44 in benign and malignant pheochromocytoma, respectively, while Hsp90 immunohistochemical staining was positive only in the cytoplasm of malignant pheochromocytoma. CONCLUSIONS: Immunohistochemical staining for Ki-67 and Hsp90 was seen in malignant pheochromocytoma. The Thompson and Kimura scales and immunohistochemical results could help to differentiate benign and malignant pheochromocytoma.