Prognostic value of Pheochromocytoma of the Adrenal Gland Scaled Score (Pass score) tests to separate benign from malignant neoplasms.

BACKGROUND: Differentiating malignant from benign pheochromocytoma has been challenging when based on histologic features. This is due to the definition of malignant pheochromocytoma which are defined by the presence of metastases. A PASS score was developed and according to many authors, a PASS score> =4 identified potentially malignant tumors. AIM: To assess the prognostic value of PASS score in differentiating benign pheochromocytomas from malignant ones.
METHODS: The records of 11 patients with tumors diagnosed as "pheochromocytoma" were identified from 1970 to 2010 in the files of the pathology, intern medicine and biochemistry departments of the Charles Nicolle hospital and Pasteur Institute. Receiver operating characteristics (ROC) curve analysis was performed to evaluate the diagnostic performance of PASS. The logistic model was developed using the 11 predictive variables. Its performance was evaluated by calculating the area under the ROC curve and comparing it with that of the PASS.
RESULTS: In benign tumors, The PASS score was <4 in 3 cases and >=4 in 6 cases. In malignant tumors, the PASS score was >=4 in both cases. According to the ROC curve analysis, a PASS equal or superior to 4 identifies malignant pheochromocytoma with a sensitivity of 50% and a specificity of 45%.
CONCLUSION: I think that PASS score, despite its low sensitivity, may help to reserve the more aggressive treatment and narrow follow up for potentially malignant tumors. Widespread of this called score with complete clinical data will help to validate these findings and to add other prognostic factors of value that could be a part of this scaled score such as immunohistochemical findings.