Fig. 8.

Overstating the risk of aggressive behavior in PPGLs using current risk stratification algorithms. All images are routine hematoxylin–eosin stains. Images A-D depict a resected pheochromocytoma with a recurrence-free follow-up time of 20 years. A Pleomorphic features. B Capsular invasion. C Comedo-type necrosis. D Vascular invasion. The Pheochromocytoma of the Adrenal gland Scaled Score (PASS) was elevated (5 points); thus, the algorithm falsely identified metastatic potential in this instance. E, F A large proportion of PPGLs arising in MEN2A patients display large, irregular nests (E) and focal tumor cell spindling (F). Large nests is a parameter listed in both the PASS and the Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP) algorithms, and tumor cell spindling is an additional PASS related parameter. From a clinical standpoint, pheochromocytomas in MEN2 patients very rarely metastasize