Pheochromocytoma - Histopathological and Clinical Update

Background: The pheochromocytoma or paraganglioma PPGL is a metabolically active tumor originating from the chromaffin cells of adrenal medulla (pheochromocytomas) or from sympathetic or parasympathetic autonomic ganglia (paragangliomas). The exact incidence of pheochromocytoma is unknown, but it is estimated to occur in 2–8 cases per 1 million people per year. The estimated prevalence in hypertensive adults is thought to range from 0.1 to 0.6 %. The foremost investigation is ususally increased urinary and plasma levels of catecholamines and their metabolites (metanephrines, normetanephrines& VMA). Histopathological and IHC features are accustomed to authenticate the diagnosis. Aim: In this study, the most frequently diagnosed tumor of adrenal gland-Pheochromocytoma along with their detailed histopathological, biochemical and clinical characterstics were studied in detail. Material and Method: A retrospective 5 year study was carried out. Brief clinical history was taken along with other relevant parameters. Histopathological data was collected and relevant details were noted. The clinical and findings of H& E sections, special stains and IHC were compiled to arrive at a final diagnosis. Results: Out of 70 cases of adrenal masses, pheochromocytoma (31 cases) was the most common tumor observed. The most common symptom was hypertension. CT scan done on 28 cases showed greater enhancement on contrast phase. The 24-hr urinary levels of VMA was elevated in 16 (51.6 %). Confluent necrosis was present in 14 cases and 3 cases showed vascular invasion histologically. Pass score was ≥4 in 9cases and less than4 in remaining 22cases. IHC panel used show positivity for Chromogranin, S-100, synaptophysin. Conclusion: We conclude that the following clinicopathological parameters should be taken into account for proper diagnosis and risk assessment of malignant behavior of pheochromocytoma. - proper clinical evaluation biochemical markers, location, size, PASS score, IHC markers.