Pre- and peri-operative characteristics, complications and outcomes of patients with biochemically silent pheochromocytomas; a case series.

PURPOSE: Pheochromocytomas are rare tumors and biochemically silent ones with normal catecholamine levels are even rarer. Up to date, biochemically inactive pheochromocytomas are poorly investigated. We aimed to systematically assess the pre- and peri-operative characteristics and the outcomes of patients with these tumors who had been treated and followed-up in 2 tertiary centers. METHODS: Clinical, laboratory and imaging data, treatment outcomes and follow-up of biochemically silent pheochromocytoma patients were recorded. RESULTS: Ten patients (5 men) [median age at diagnosis 52.5 years (24-72)] were included. Adrenal masses were incidentally discovered in all patients except from one who presented with pheochromocytoma-related manifestations. Twenty-four-hour urine metanephrine and normetanephrine levels were in the low-normal, normal and high-normal range in 4, 4 and 2 patients and in 1, 6 and 3 patients, respectively. Tumors were unilateral [median size 46 mm (17-125)] and high density on pre-contrast CT imaging or high signal intensity on T2-weighted MRI scans were found in all cases. Pre-operatively, 5 patients were treated with phenoxybenzamine [median total daily dose 70 mg (20-100)]. Intra-operatively, 4 patients developed hypertension requiring vasodilator administration and 8 developed hypotension; vasoconstrictors were required in 5 cases. One patient, not pre-operatively treated with phenoxybenzamine, developed Takotsubo cardiomyopathy. During a median 24-month (12-88) follow-up period, one patient had disease progression. CONCLUSIONS: The majority (90%) of patients with biochemically silent pheochromocytomas developed hemodynamic instability during adrenal surgery. In patients with biochemically silent adrenal lesions and a high suspicion index for pheochromocytoma based on tumor imaging characteristics, pre-operative alpha-blockade treatment may be advisable.

Diabetic ketoacidosis in patients treated with SGLT2 inhibitors: experience at a tertiary hospital.

PURPOSE: Diabetic ketoacidosis (DKA) is a rare and life-threatening complication in patients with diabetes. Sodium-glucose co-transporter-2 inhibitors (SGLT2i) have rarely been associated with ketoacidosis. The aim of this retrospective study was to investigate DKA episodes occurring after SGLT2i treatment and to compare them to DKA episodes due to other causes. METHODS: The medical records of the years 2018-2020 related to clinical and biochemical characteristics and to treatment of six patients with DKA due to SGLT2i were reviewed. They were compared to those of 12 patients with DKA due to other causes. RESULTS: On admission, the most common symptom was abdominal pain. Glucose levels (median, min-max) were lower in patients with SGLT2i-induced DKA compared to those with DKA due to other causes (229 (150-481) vs. 458.5 (332-695) mg/dl, p = 0.007), whereas no statistical difference was observed in HbA1c and in the severity of DKA (pH, HCO3, CO2, and anion gap). The duration of insulin infusion (41 (33-124) vs. 21.50 (11-32) h, p < 0.001) and the time required until DKA resolution (39 (31-120) vs. 19 (9-28) h, p < 0.001) were higher in patients with SGLT2i-induced DKA than those with DKA due to other causes. In addition, there were increased fluid requirements (14 (8-22.75) vs. 5.5 (2-24) L, p = 0.013) and longer hospitalization time (11 (6-22) vs. 5.5 (2-14) days, p = 0.024) in patients with SGLT2i-induced DKA. No statistically significant differences were observed in total intravenous insulin and potassium administration until DKA resolution. CONCLUSIONS: Patients with SGLT2i-induced DKA had lower serum glucose levels on admission and required increased fluid administration and longer time to recover from acidosis compared to patients with DKA from other causes.