Resident University of Maryland Midtown Campus Baltimore, Maryland, United States
Introduction: Pheochromocytoma is a rare neuroendocrine tumor arising from adreno-medullary-chromaffin cells. Surgical resection is considered curative treatment however recurrence can occur in a subset of cases despite resection. We present a case where a patient with neurofibromatosis type 1 (NF1) developed metastatic pheochromocytoma 8 years after initial surgical resection.
Case Description: A 44-year-old woman with a history of NF1 presented to the emergency department with diffuse body pain, palpitations, and hypertension. On further evaluation with a full body CT scan, she was found to have multiple pulmonary nodules, diffuse mixed lucent and sclerotic lesions involving the axial and appendicular skeleton, and a 1.7cm breast mass. The patient had previously been diagnosed with bilateral pheochromocytomas 8 years prior to the current presentation and underwent complete right adrenalectomy and subtotal left adrenalectomy at the time. Her plasma metanephrines one year post-operatively were normal. She was then subsequently lost to follow-up until her current presentation. Due to her history, plasma metanephrines and urine metanephrines were sent which showed elevated values greater than two times the upper limit of normal. Plasma metanephrines were 2.83 nmol/L (0-0.49 nmol/L), plasma normetanephrines were >50 nmol/L (0.00-0.89 nmol/L), the urine metanephrine/creatinine ratio was 3156 ug/g (0-300ug/g) and the urine normetanephrine/creatinine ratio was 114828 ug/g (0-400ug/g). She then underwent a Ga-68-DOTA PET/CT which demonstrated innumerable DOTATATE avid lesions along the axial and appendicular skeleton compatible with a metastatic neuroendocrine tumor. She was started on alpha blockade with doxazosin followed by beta blockade with metoprolol for medical management while hospitalized and discharged home with oncology and endocrinology follow-up.
Discussion: The recurrence rate of pheochromocytoma after resection is approximately 6%-16.5%. It may recur locally, distantly, or metastatically at sites where chromaffin cells are not found. Pheochromocytoma occurs in 0.1-5.7% of patients with NF1 and NF1 patients have a 3.4-fold higher risk of developing recurrent disease than individuals with sporadic tumor. There is no curative treatment for metastatic pheochromocytoma and treatment with surgery, Iobenguane I-131, and chemotherapy are available to improve quality of life. Due to the increased risk of recurrence in patients with NF1, a multidisciplinary approach is essential during initial diagnosis and follow-up treatment. Increased post-operative monitoring may be warranted given the higher risk of recurrence in patients with NF1 who are diagnosed with initial pheochromocytoma.
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