Abstract
BACKGROUND: Pheochromocytoma is a rare catecholamine-secreting tumor that can present with severe hypertensive episodes and other symptoms due to excessive catecholamine release. Approximately 30% of pheochromocytomas are associated with hereditary syndromes, including multiple endocrine neoplasia type 2A (MEN2A), an autosomal dominant disorder caused by mutations in the RET proto-oncogene. MEN2A is characterized by the presence of medullary thyroid carcinoma, pheochromocytoma, and primary hyperparathyroidism. CASE PRESENTATION: We report the case of a 19-year-old female who presented with pheochromocytoma without experiencing a crisis, despite having a significant adrenal mass and undergoing high-dose glucocorticoid treatment. Genetic testing revealed a heterozygous missense mutation in the RET gene (c.1900T > C: p. Cys634Arg), associated with MEN2A. Further endocrine evaluation identified a thyroid nodule with mildly elevated calcitonin levels, but normal electrolyte and parathyroid hormone levels. Over a 15-month postoperative follow-up, the patient exhibited persistently mild hypercalcitoninemia with stable thyroid nodule size, while PTH and serum calcium levels showed a progressive increase. Further parathyroid scintigraphy using 99mTc-MIBI was performed, yielding a negative result for parathyroid adenoma. CONCLUSION: Patients with MEN2A require comprehensive, long-term follow-up to monitor for recurrence of pheochromocytoma and the development of additional endocrine neoplasms. This case highlights the role of genetic testing in guiding the management of hereditary pheochromocytoma and supports the importance of personalized monitoring strategies in patients with MEN2A.