Table 2.

Overview on patients with PPGL diagnosed by imaging and concomitant syndromic presentation, positive family history or metastatic disease.

#	Clinical context	Reason for inclusion as putatively incidental
1	Family history or syndromic presentation	First-degree relative with PPGL, hospitalization for uncontrolled diabetes mellitus type 2 (HbA1c 10%); routine abdominal ultrasound followed by CT scan revealed pheochromocytoma
2	Family history or syndromic presentation	Hospitalization for insufficiently controlled diabetes mellitus type 2. Indication for abdominal sonography because of weight loss of 7 kg. Thereby, incidental finding of an adrenal mass of 6 cm. Following study entry, family history reveals one daughter and one granddaughter ‘with a benign adrenal tumor’
3	Family history or syndromic presentation	Positive family history was only revealed after surgery and genetic diagnosis (of a SDHD mutation) as the patient had no contact to other family members
4	Family history or syndromic presentation	Neurofibromatosis was first diagnosed in 1998; arterial hypertension was first described in 2004. Right sided adrenal PPGL was detected incidentally in 2012 through imaging for abdominal pain
5	Family history or syndromic presentation	Patient was referred to a nephrologist due to elevated creatinine levels in 10/2013, which led to sonographic detection of a clear cell carcinoma of the right kidney. During a follow-up in 08/2015, an adrenal mass on the right side was detected by ultrasound. Patient came to the outpatient clinic with suspicion of an adrenocortical adenoma
6	Family history or syndromic presentation	Discovery of an adrenal tumor after abdominal imaging for unrelated reason; VHL was diagnosed clinically and genetically only after patient had undergone surgery
7	Family history or syndromic presentation	Patient had known NF1 first diagnosed in 1964. Arterial hypertension had been first diagnosed in 1996. In 2015, the patient was seen by her general practitioner for ‘kidney pain’, which revealed a mass in the right retroperitoneal space. The patient was free of typical symptoms other than arterial hypertension, which had been known for many years
8	Family history or syndromic presentation	Abdominal ultrasound, which revealed bilateral adrenal tumors was performed due to abdominal pain. Only further clinical evaluation (with detection of neurofibroma) in the study center made the connection with the presence of neurofibromatosis
9	Family history or syndromic presentation	Diagnostic imaging performed for unexplained weight loss and increasingly difficult to maintain blood glucose levels with known diabetes type 1 revealed a tumor in left adrenal. Genetic testing was performed following surgery of the pheochromocytoma, which found a mutation for SDHC
10	Metastatic disease	Prolonged respiratory infection with weight loss of 7 kg, abdominal CT scan revealed mediastinal lymph nodes, CT guided fine needle biopsy resulted in the diagnosis of paraganglioma which was found to be metastasized in the liver and the bone
11	Metastatic disease	Patient was referred as an inpatient in sepsis which led to the diagnosis of endocarditis and further imaging revealed metastasized PGL
12	Metastatic disease	Urinary retention let to the diagnosis of an adrenal tumor (with the initial suspicion of adrenocortical carcinoma) with the final diagnosis of metastatic PGL
13	Metastatic disease	Abdominal CT scan was performed due to unspecific abdominal pain, which revealed a pheochromocytoma. Metastases were detected only 6 months after primary surgery
14	Metastatic disease	Patient was referred because his primary care physician had made an abdominal ultrasound because of a suspected kidney stone. Unexpectedly, a large adrenal mass on the right side was found. Retrospectively, the patient for many years had signs of excessive sweating and hypertension but these issues became apparent only when referred to the study center, where metastatic disease was diagnosed