Vague neuroglycopenic complaints camouflage diagnosis of adolescent insulinoma: a case report

Abstract

BackgroundInsulinoma is a rare diagnosis in the general population with estimates of 1 in 250,000 people per year. Reports of these pancreatic islet cell tumors are even more unusual in children and adolescents. Chronic hypoglycemia due to an insulinoma often presents with neuroglycopenic symptoms that can easily be overlooked, especially in adolescents where nonspecific complaints are common. This may result in delayed diagnosis with prolonged periods of untreated hypoglycemia and associated complications. The rarity of pediatric insulinoma, vagueness of presenting symptoms, and challenge of tumor localization make insulinoma a true diagnostic quandary for clinicians.Case PresentationIn this report, we present a 15-year-old female who visited her primary care provider complaining of intermittent episodes of altered mental status including fatigue, irritability, and poor concentration. Her outpatient management included routine laboratory studies, drug screening, electroencephalogram (EEG), valproic acid initiation, CT scan of the abdomen, and endoscopic ultrasound with documentation of hypoglycemia, but otherwise inconclusive results. The patient was admitted to a tertiary children’s hospital with severe refractory hypoglycemia 8 months after the initial evaluation. A serum critical sample was obtained and magnetic resonance imaging (MRI) of the abdomen performed which confirmed the presence of a pancreatic mass ultimately identified as an insulinoma. She went on to have surgical resection of her tumor resulting in complete resolution of her hypoglycemia and associated symptoms.ConclusionWithin this report we demonstrate the importance of being vigilant for fasting hypoglycemia secondary to insulinoma even when the patient presents with nonspecific symptoms such as fatigue, irritability, or problems with concentration. If these neuroglycopenic complaints are unnoticed or misdiagnosed, patients with a potentially curable disease are put at risk of neurologic injury, or even death, due to untreated severe hypoglycemia.

Sporadic Insulinoma Presenting as Early Morning Night Terrors

“…This case, along with previously published case reports, highlights the importance of maintaining a high index of suspicion for hypoglycemia in patients who develop altered mentation (such as night terror–like events) or other signs of hypoglycemia, 12, 13 particularly in the early morning hours after a night of sleep. The difficulty in making this diagnosis is highlighted by the average prolonged time to diagnosis, with 1 study demonstrating a median of 24 months from the onset of symptoms to diagnosis.…”

Insulinoma masquerading as a loss of consciousness in a teenage girl: case report and literature review

“…The spectrum of symptoms included confusion, palpitation, sweating, tremors, hunger, irritability, dizziness, drowsiness, generalized weakness, abdominal pain, psychomotor slowing, syncope and seizures. Most of the episodes occurred during the morning hours, after exercise or fasting, and resolved after food or juice intake [ 9 , 10 , 14 , 15 , 17 – 19 , 27 ]. Eighteen children experienced seizure activity [ 13 , 14 , 16 , 18 – 21 , 23 – 25 , 27 , 29 , 30 ], four children were found in a comatose state [ 29 , 30 ], three children had mental retardation as sequelae after surgery [ 11 , 27 , 30 ] and two children died [ 22 , 30 ].…”

“…Duration of hypoglycemia symptoms before the diagnosis of insulinoma in children ranged from 1 month to 7 years, and averaged 10–13.4 months [ 14 , 17 ]. The reasons behind the delayed diagnosis likely include not seeking medical attention due to symptom ambiguity [ 10 ], as well as failure of conventional imaging methods such as CT [ 10 ] and ultrasound [ 11 ] to localize the tumor. In our case, the family did not seek medical attention for at least 2–3 months because EM’s symptoms of increased fatigue, tremors, sweating, and somnolence followed skipped meals and resolved after eating, making her symptoms mimic hunger, until EM became unresponsive.…”

“…This delay in diagnosis may be dangerous, since prolonged hypoglycemia can lead to seizures, mental status changes and sometimes death [ 30 ]. Halpin et al recently reported a 15-year-old adolescent female with symptoms of fatigue, confusion, irritability and staring lasting for 5 months before she was found to have a 1.3 cm size insulin-secreting tumor [ 10 ]. This and our case emphasize that in the adolescent population, “normal” teenage behaviors can mask hypoglycemia symptoms, making the diagnosis more difficult in this age group.…”

“…AN is thought to be caused by proliferation of fibroblasts and keratinocytes when excess insulin binds to insulin like growth factor-1 receptors [ 34 ]. This would lead one to believe that all cases of hyperinsulinism would be associated with AN; however, not all insulinomas present with AN [ 9 , 10 ]. Why AN is present in some and not in others is not clear.…”