Where´s the Insulinoma? A clinical case report

Abstract

The suspicion of insulinoma in an individual with adrenergic
symptoms and / or neuroglycopenia must be the first concern
in the differential diagnosis of hypoglycaemia. Insulinoma is the
most frequent endocrine tumour of the pancreas and appears
at any age, being more frequent between 40 and 60 years. The
diagnosis is clinical and it can be difficult to make in the presence
of doubtful symptoms of neuroglycopenia or adrenergic symptoms
after meals. Whipple’s triad of - glycaemia below 50 mg/dl and
symptoms / signs of hypoglycaemia that revert with administration of glucose - is strongly suggestive of insulinoma, and when
associated with blood insulin inappropriately high, is diagnostic of
insulinoma. The authors describe the case of a 58-year-old male
patient, with a clinical picture characterized by multiple episodes
of confusion, migraine, bewilderment, irritability, agitation and
diaphoresis, of nearly 8 months duration. The complaints were
not properly evaluated initially and the patient was treated with
sedative drugs. A fasting glycaemia of 38 mg/dl made insulinoma
a probable diagnosis, and this was confirmed by the 72 hour
fast test. Difficulties arose, as usual, in locating the tumour with
imaging methods (ultrasound, tomography scan, octreotide scan
and endoscopic ultrasound) and only selective arteriography with
catheterization of the branches of the coeliac artery revealed the
tumour, located in the head of the pancreas. Surgical treatment
consisted of tumour enucleation. The histological findings confirmed the diagnosis of benign insulinoma. The peculiarities of the
diagnosis and particularities of the image studies in insulinoma
are discussed.