Endocrine Abstracts

Introduction: Pheochromocytomas are rare neuroendocrine tumors originating from chromaffin cells in the adrenal medulla, secreting catecholamines and causing symptoms such as hypertension, anxiety, panic attacks, palpitations, and headaches. An adrenal gland incidentaloma is identified as an unintentional discovery in approximately 3 - 4 % of computed tomography (CT) abdomens performed. Pheochromocytoma is diagnosed in about 5% of adrenal incidentalomas. Diagnosing pheochromocytoma is challenging due to symptoms overlapping with other medical conditions.

Case report: We present a 33-year-old patient evaluated in the emergency department for abdominal pain. Ultrasound revealed a 12 cm oval heterogeneous formation near the lower spleen pole of unclear origin and inflammatory changes at the descending to sigmoid colon transition. A subsequent upper abdomen CT revealed a left adrenal gland formation measuring 11 × 8.8 × 11 cm with a native density of 30 Hounsfield units (HU), with 60 % absolute wash-out and 40 % relative wash-out. An irregular hypervascular zone (21 × 20 × 25 mm) in the left kidney’s lower pole mesentery prompted gastroenterological examinations (esophagogastroscopy, colonoscopy, magnetic resonance (MR) enterography), all yielding normal results. The patient had normal blood pressure; his only symptom was mild abdominal pain. Laboratory findings showed slightly elevated normetanephrine in serum (0.80 nmol/l, reference interval 0.13-0.62 nmol/l) and twice-elevated normetanephrine in urine (0.48 umol/dU, reference interval <0.24 umol/dU). Metanephrine values in serum and urine were within reference intervals. Repeated urine metanephrine and normetanephrine findings were normal as well as androgen and cortisol levels. Therefore, the differential diagnosis included pheochromocytoma and adrenocortical carcinoma which was considered as more plausible option. Surgery was recommended, however perioperative preparation according to the protocol for pheochromocytoma was not performed since the biochemical findings were not confirmatory for the diagnosis of pheochromocytoma. The patient underwent a left-sided adrenalectomy without complications. Pathohistological analysis confirmed a composite pheochromocytoma with a ganglioneuroma component in 5 - 10 % of tumors, a PASS score (a pheochromocytoma of the adrenal gland scaled score) >4, and a GAPP score (the grading of adrenal pheochromocytoma and paraganglioma) of 5/10. Follow-up adrenal gland MRI revealed no disease recurrence.

Conclusion: The diverse clinical presentations of pheochromocytoma, ranging from asymptomatic to displaying atypical symptoms, underscore the diagnostic challenges posed by this rare neuroendocrine tumor. Given its potential to precipitate hypertensive crises, arrhythmias, and myocardial infarctions, early recognition and prompt intervention become imperative for mitigating severe complications.