Endocrine Abstracts

Background: Pheochromocytoma is a rare adrenal tumor that can present with a variety of different symptoms. The cardinal symptoms are paroxysmal palpitations, headaches and sweating together with paroxysmal or persistent hypertension. Increasing use of CT scan contribute to the discovery of more adrenal incidentalomas and therefore more pheochromocytomas due to the workup of the incidentalomas. We intended to investigate if the presentation of the pheochromocytoma was different in the incidentaloma group, if so, what symptoms the tumor presented with, and if the tumors was different in size and metanephrine release.

Methods: Twenty-nine cases with pheochromocytomas examined and treated at Akershus University Hospital, Norway, during the last 20 years were reviewed. Age, year diagnosed, tumor characteristics, biochemistry, radiology, medical treatment before surgery, complications during surgery, and blood pressure measurement before, during and after the operation were registered.

Results: Of the 29 cases included, 70.4% presented as incidentalomas and 26.6% was discovered based on clinical symptoms and none due to genetic screening. The mean (±S.D.) age of the incidentalomas (58.0±12.3) years was significantly higher than the patients diagnosed because of clinical suspicion (42.0±9.9) years. Females were overrepresented in both groups and was in total 65.6%. There was no significant difference in blood pressure between the two groups (incidenthaloma vs clinical group), systolic 142.0 (±21.9) vs 154.2 (±18.8) mmHg, tumor size 4.9 (±3.0) vs 4.2 (±1.0) cm or normetanephrine median (range) 2.7 (0.7–26.2) vs 5.7 (3.1–44.0) nmol/l nor the excretion of metanephrine 1.5 (0.3–12.6) vs 1.4 (0.3–6.1) nmol/l. Out of the 19 incidentalomas 72.2% were retrospectively symptomatic and the most common symptoms were sweating, palpitations and headaches, followed by palpitations and tremor but these symptoms were rarely present at the same time. The last 10 years from 2010 to 2020, 15 incidenthalomas made up the 20 pheochromocytomas vs 4 of 7 from 2000 to 2010.

Conclusion: Our hospital diagnosed more pheochromocytomas the last years due to increasing discovery of incidentalomas on CT imaging and 72.2% of these incidenthalomas were retrospectively symptomatic. This points out the importance of investigating all incidentalomas biochemically and making a good medical history for symptoms as undiagnosed pheochromocytomas can be life-threatening.

Reference: H Falhammar et al. Initial clinical presentation and spectrum of pheochormocytoma: a study of 94 cases from a single center; Endocrine Connections (2018)7, 186–192