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Open access

Yael Lefkovits and Amanda Adler

Summary

Necrobiosis lipoidica diabeticorum (NLD) is a chronic granulomatous dermatitis generally involving the anterior aspect of the shin, that arises in 0.3–1.2% of patients with diabetes mellitus (1). The lesions are often yellow or brown with telangiectatic plaque, a central area of atrophy and raised violaceous borders (2). Similar to other conditions with a high risk of scarring including burns, stasis ulcers and lupus vulgaris, NLD provides a favourable environment for squamous cell carcinoma (SCC) formation (3). A number of cases of SCC from NLD have been recorded (3, 4, 5); however, our search of the literature failed to identify any cases of either metastatic or fatal SCC which developed within an area of NLD. This article describes a patient with established type 1 diabetes mellitus who died from SCC which developed from an area of NLD present for over 10 years. Currently, there are a paucity of recommendations in the medical literature for screening people with NLD for the early diagnosis of SCC. We believe that clinicians should regard non-healing ulcers in the setting of NLD with a high index of clinical suspicion for SCC, and an early biopsy of such lesions should be recommended.

Learning points:

  • Non-healing, recalcitrant ulcers arising from necrobiosis lipoidica diabeticorum, which fail to heal by conservative measures, should be regarded with a high index of clinical suspicion for malignancy.

  • If squamous cell carcinoma is suspected, a biopsy should be performed as soon as possible to prevent metastatic spread, amputation or even death.

  • Our literature search failed to reveal specific recommendations for screening and follow-up of non-healing recalcitrant ulcers in the setting of necrobiosis lipoidica diabeticorum.

  • Further research is required in this field.

Open access

D Cappellani, C Sardella, M C Campopiano, A Falorni, P Marchetti and E Macchia

Summary

Insulin autoimmune syndrome (IAS), or Hirata disease, is a rare hypoglycaemic disorder caused by the presence of high titer of insulin autoantibodies (IAA) in patients without previous exposure to exogenous insulin. Even though its pathogenesis is not fully understood, striking evidences link IAS to previous exposure to sulphydryl-containing medications, like alpha-lipoic acid, a widely used nutritional supplement. Although challenging, a careful differential diagnosis from other causes of hyperinsulinaemic hypoglycaemia (such as insulinoma) is mandatory, since these conditions require different therapeutic approaches. In the present study, we report a 35-year-old woman originally from Sri Lanka who was referred to our University Hospital on suspicion of occult insulinoma. Her medical history was positive for endometriosis, treated with estroprogestins and alpha-lipoic acid. The latter supplement was begun 2 weeks before the first hypoglycaemic episode. Our tests confirmed the presence of hypoglycaemia associated with high insulin and C-peptide concentrations. When insulin concentrations were compared using different assays, the results were significantly different. Moreover, insulin values significantly decreased after precipitation with polyethylene glycol. An assay for IAA proved positive (530 U/mL). A genetic analysis revealed the presence of HLA-DRB1*04,15, an immunogenetic determinant associated with IAS. On the basis of clinical data we avoided a first-line approach with immunosuppressive treatments, and the patient was advised to modify her diet, with the introduction of frequent low-caloric meals. During follow-up evaluations, glucose levels (registered trough a flash glucose monitoring system) resulted progressively more stable. IAA titer progressively decreased, being undetectable by the fifteenth month, thus indicating the remission of the IAS.

Learning points:

  • Insulin autoimmune syndrome (IAS) is a rare cause of hyperinsulinaemic hypoglycaemia, whose prevalence is higher in East Asian populations due to the higher prevalence of specific immunogenetic determinants. Nevertheless, an increasing number of IAS cases is being reported worldwide, due to the wide diffusion of medications such as alpha-lipoic acid.

  • Differential diagnosis of IAS from other causes of hyperinsulinemic hypoglycaemia is challenging. Even though many tests can be suggestive of IAS, the gold standard remains the detection of IAAs, despite that dedicated commercial kits are not widely available.

  • The therapeutic approach to IAS is problematic. As a matter of fact IAS is often a self-remitting disease, but sometimes needs aggressive immunosuppression. The benefits and risks of any therapeutic choice should be carefully weighted and tailored on the single patient.

Open access

Tess Jacob, Renee Garrick and Michael D Goldberg

Summary

Metformin is recommended as the first-line agent for the treatment of type 2 diabetes. Although this drug has a generally good safety profile, rare but potentially serious adverse effects may occur. Metformin-associated lactic acidosis, although very uncommon, carries a significant risk of mortality. The relationship between metformin accumulation and lactic acidosis is complex and is affected by the presence of comorbid conditions such as renal and hepatic disease. Plasma metformin levels do not reliably correlate with the severity of lactic acidosis. We present a case of inadvertent metformin overdose in a patient with both renal failure and hepatic cirrhosis, leading to two episodes of lactic acidosis and hypoglycemia. The patient was successfully treated with hemodialysis both times and did not develop any further lactic acidosis or hypoglycemia, after the identification of metformin tablets accidentally mixed in with his supply of sevelamer tablets. Early initiation of renal replacement therapy is key in decreasing lactic acidosis-associated mortality.

Learning points:

  • When a toxic ingestion is suspected, direct visualization of the patient’s pills is advised in order to rule out the possibility of patient- or pharmacist-related medication errors.

  • Though sending a specimen for determination of the plasma metformin concentration is important when a metformin-treated patient with diabetes presents with lactic acidosis, complex relationships exist between metformin accumulation, hyperlactatemia and acidosis, and the drug may not always be the precipitating factor.

  • Intermittent hemodialysis is recommended as the first-line treatment for metformin-associated lactic acidosis (MALA).

  • An investigational delayed-release form of metformin with reduced systemic absorption may carry a lower risk for MALA in patients with renal insufficiency, in whom metformin therapy may presently be contraindicated.

Open access

Noman Ahmad, Abdulmonem Mohammed Almutawa, Mohamed Ziyad Abubacker, Hossam Ahmed Elzeftawy and Osama Abdullah Bawazir

Summary

An insulinoma is a rare tumour with an incidence of four cases per million per year in adults. The incidence in children is not established. There is limited literature available in children with insulinoma, and only one case is reported in association with Down’s syndrome in adults. Insulinoma diagnosis is frequently missed in adults as well as in children. The Whipple triad is the most striking feature although it has limited application in young children. Hypoglycaemia with elevated insulin, C-peptide and absent ketones is highly suggestive of hyperinsulinism. We present a case of 10-year-old boy with Down’s syndrome with recurrent insulinoma. He was initially misdiagnosed as having an adrenal insufficiency and developed cushingoid features and obesity secondary to hydrocortisone treatment and excessive sugar intake. The tumour was successfully localised in the head of the pancreas with an MRI and octreotide scan on first presentation. Medical treatment with diazoxide and octreotide could not achieve normal blood glucose levels. The insulinoma was laparoscopically enucleated and pathological examination confirmed a neuroendocrine tumour. Subsequently, he had complete resolution of symptoms. He had a recurrence after 2 years with frequent episodes of hypoglycaemia. The biochemical workup was suggestive of hyperinsulinism. MRI and PET scan confirmed the recurrence at the same site (head of the pancreas). He had an open laparotomy for insulinoma resection. The pathology was consistent with benign insulinoma, and subsequently, he had complete resolution of symptoms.

Learning points:

  • Insulinoma is a very rare tumour in children; it should be considered in the differential diagnosis of hypoglycaemia with absent ketones.

  • Refractory neurological symptoms like seizure, migraine, mood changes and regression of learning abilities should suggest evaluation for hypoglycaemia.

  • MRI with contrast and PET scan would localise the majority of pancreatic beta islet cell lesions.

  • Medical treatment with diazoxide, octreotide and the addition of corn starch in feeds is not curative but can be supportive to maintain normoglycemia until the surgical resection.

  • Surgical resection is the only curative treatment. The surgical procedure of choice (laparoscopic/open laparotomy) depends on local expertise, preoperative localisation, tumour size and number.

  • Surgical treatment results in complete resolution of symptoms, but all cases should be closely followed up to monitor for recurrence. The recurrence rate is four times higher in MEN1 cases.

Open access

Marianne Geilswijk, Lise Lotte Andersen, Morten Frost, Klaus Brusgaard, Henning Beck-Nielsen, Anja Lisbeth Frederiksen and Dorte Møller Jensen

Summary

Hypoglycemia during pregnancy can have serious health implications for both mother and fetus. Although not generally recommended in pregnancy, synthetic somatostatin analogues are used for the management of blood glucose levels in expectant hyperinsulinemic mothers. Recent reports suggest that octreotide treatment in pregnancy, as well as hypoglycemia in itself, may pose a risk of fetal growth restriction. During pregnancy, management of blood glucose levels in familial hyperinsulinemic hypoglycemia thus forms a medical dilemma. We report on pregnancy outcomes in a woman with symptomatic familial hyperinsulinemic hypoglycemia, type 3. During the patient’s first pregnancy with a viable fetus octreotide treatment was instituted in gestational age 23 weeks to prevent severe hypoglycemic incidences. Fetal growth velocity declined, and at 37 weeks of gestation, intrauterine growth retardation was evident. During the second pregnancy with a viable fetus, blood glucose levels were managed through dietary intervention alone. Thus, the patient was advised to take small but frequent meals high in fiber and low in carbohydrates. Throughout pregnancy, no incidences of severe hypoglycemia occurred and fetal growth velocity was normal. We conclude that octreotide treatment during pregnancy may pose a risk of fetal growth restriction and warrants careful consideration. In some cases of familial hyperinsulinemic hypoglycemia, blood glucose levels can be successfully managed through diet only, also during pregnancy.

Learning points:

  • Gain-of-function mutations in GCK cause familial hyperinsulinemic hypoglycemia.

  • Hypoglycemia during pregnancy may have serious health implications for mother and fetus.

  • Pregnancy with hyperinsulinism represents a medical dilemma as hypoglycemia as well as octreotide treatment may pose a risk of fetal growth restriction.

  • In some cases of familial hyperinsulinemic hypoglycemia, blood glucose levels can be successfully managed through diet only.