ESPE Abstracts

Introduction: Tuberous sclerosis complex (TSC) is an autosomal dominant condition caused by a loss-of-function mutation in tumor suppressor genes TSC1/TSC2 which are involved in the inhibition of mTOR signaling implicated in cell proliferation. Major clinical features includes cardiac rhabdomyomas, renal cysts, epilepsy associated to cerebral dysplasia evidenced by cortical tubers and skin manifestation as: angiofibromas, fibrous plaques and the Shagreen patch. Around six cases of insulinoma had been described in adult population whith TSC. Childhood insulinoma is rare, occurring either in isolation or in association with multiple endocrine neoplasia type 1(MEN1), 5-10% are malingnant. Diagnosis of insulinoma is based on the presence of Whipple´s triad, detectable insulin during hypoglycemia and is located by MRI scan or 6-L18F-fluorodihydroxyphenylalanine(18-F-DOPA)PET-CT.

Objective: To present a 14-year-old girl with diagnosis of TSC and insulinoma

Case Report: A girl with diagnosis of TSC had a prenatal diagnosis of cardiac rabdomyomas. She was born at term, with normal weight/length, postnatally ultrasound confirmed rabdomyomas and detected unilateral multiple renal cysts. At one-year-old presented absence epilepsy, the cerebral MRI showed abnormalities consistent with cerebral tubers. Learning was normal. At 14-years-old started with episodes of confusion with slurred speech upon awakening after prolonged sleeps in weekend. Although the electroencephalograph was normal, changes in anti-epilepsy pharmacotherapy were made in an attempt to resolve these episodes whithout improvement during seven months until hypoglycemia was detected during one episode.

Upon physical examination normal stature and BMI, angiofibroma, fibrous plaque and Shagreen patch were found. A fasting tolerance test allowed to detect after 10 hours: Glucose 41mg/dl(55-110), insulin28,7mUI/l (<1) C-peptide 4,6 ng/ml(0,8-5,2). Cortisol 109 nmol/l(101-536), GH 4,76ng/ml (>5), IGF1: 414ng/ml(220-996). PRL:7,7 ng/ml(0-14), Ca:9.3 mg%(8,4-10.2), P:2,5mg% (2,5-5.0), PTH:18.04 pg/ml (10-55). Hyperinsulinism was diagnosed without evidence of MEN1. Abdominal MRI scan showed a low-signal-density on T1-weighted-images and a high-signal-density on T2-weighted-images that enhanced with contrast of 27x23x20 mm in the pancreas body with concordant finding in the 18-F-DOPA-PET-CT scanning of a increased focal uptake(SUV max 23.3).

She underwent partial pancreatectomy with perioperative frozen section. Histology diagnosis of insulinoma surrounded by a fibrous capsule without infiltration confirmed diagnosis of benign insulinoma. Postoperatively euglycemia, elevated β-OHbutyrate:0,39(< 0,35mmol/l) and NEFA:0,64 mmol/l(0,09-0,60) after prolonged fasting suggested absence of recurrence during 6 months of follow-up.

Conclusion: Insulinoma in TSC should be consider in patients with changes in neurologic symptoms, normal EEG without response to pharmacotherapy.