Scientific publications

Hypoglycemic Syndrome without Hyperinsulinemia. A Diagnostic Challenge

Pérez-Pevida B (1), Idoate MÁ [SP] (2), Fernández-Landázuri S (3), Varo N [SP] (3), Escalada J [SP] (4).
(1) Department of Endocrinology and Nutrition, Clínica Universidad de Navarra, Avenida Pio XII 36, 31008, Pamplona, Spain.
(2) Department of Pathology, Clínica Universidad de Navarra, Pamplona, Spain.
(3) Department of Biochemistry, Clínica Universidad de Navarra, Pamplona, Spain.
(4) Department of Endocrinology and Nutrition, Clínica Universidad de Navarra, Avenida Pio XII 36, 31008, Pamplona, Spain. 

Magazine: Endocrine Pathology

Date: Jan 22, 2016

Biochemistry [SP] Endocrinology and Nutrition [SP]

ABSTRACT

The most common cause of organic fasting hypoglycemia in adults is the presence of an insulin-producing pancreatic adenoma, but when high insulin levels are not found, the differential diagnosis is challenging. Misdiagnosis can lead to an unnecessary pancreatectomy.

Insulin concentrations may be low in some cases despite a clinical history suggestive of insulinoma. In these cases, a proinsulinoma should be suspected, although the rarity of this condition requires an extensive workup before reaching a final diagnosis. We describe an unusual case of a 38-year-old man with a severe hypoglycemic syndrome due to a proinsulin-secreting pancreatic adenoma.

Insulin was measured by the specific assay and suppressed under the lower detection limit during fasting hypoglycemia. Serum proinsulin and C-peptide levels were abnormally elevated, and further tests revealed an islet cell tumor.

The tumor was surgically removed, relieving the fasting hypoglycemia. Histopathological study showed a conventional well-differentiated neuroendocrine tumor with high immunoreactivity against proinsulin and with lesser intensity against insulin.

Interestingly, GS-9A8 antibody clone used for immunostaining proinsulin did not cross-react with human insulin or C-peptide, providing an unbiased picture of proinsulin secretion.

The resolution of symptoms, the fall of proinsulin concentrations after tumor removal and the histopathology study confirmed the diagnosis of proinsulinoma.

CITATION  Endocr Pathol. 2016 Jan 22.

you maybe interested

WHAT TECHNOLOGY
DO WE USE?

The Clínica is the greater private hospital with technological equipment of Spain, all in a single center.

Imagen de un PET, tecnología de vanguardia en la Clínica Universidad de Navarra

OUR
PROFESSIONALS

The professionals of the Clínica perform continuous research and training, always to the benefit of the patient.

Imagen profesionales de la Clínica Universidad de Navarra

WHY CHOOSE
THE CLINICA?

Learn why we are different from other healthcare centers. Quality, speed, comfort and results.

Imagen del edificio de la Clínica Universidad de Navarra