Acanthosis nigricans (AN) is a common dermatosis associated with hyperinsulinemia and insulin resistance. However, AN has been rarely reported in patients with insulinoma, a state of persistent hyperinsulinemia. We present a case of metastatic insulinoma, in whom AN manifested after the first cycle of peptide receptor radionuclide therapy (PRRT). A 40-year-old man was diagnosed with metastatic insulinoma after 5 months of symptomatic hypoglycemia. Within 1 month post PRRT, the patient became euglycemic but developed a pigmented, pruritic rash which was confirmed on biopsy as AN. We discuss the rare manifestation of AN in subjects with insulinoma, the role of insulin in the pathogenesis of AN, malignant AN in non-insulin-secreting malignancies and association with other insulin-resistant endocrinopathies such as acromegaly.
Acanthosis nigricans (AN) is a common dermatosis which is typically asymptomatic and associated with the hyperinsulinemic state.
Malignant AN can rapidly spread, cause pruritus and affect mucosa and the oral cavity.
AN is extremely rare in patients with insulinoma despite marked hyperinsulinemia.
Peptide receptor radionuclide therapy might have triggered TGF-α secretion in this subject which led to malignant AN.
Rapid spread or unusual distribution of pruritic AN warrants further investigation to exclude underlying malignancy.
Karen LoechnerDivision of Endocrinology, Department of Pediatrics, Children’s Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia, USA Division of Endocrinology, Department of Pediatrics, Connecticut Childrens Medical Center, Farmington, Connecticut, USA
Briana C PattersonDivision of Endocrinology, Department of Pediatrics, Children’s Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia, USA Aflac Cancer and Blood Disorders Center of Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
Insulinomas are a rare cause of persistent hypoglycemia in a previously healthy child. In addition to symptoms of hypoglycemia, individuals with insulinomas usually present with a history of incessant caloric intake and weight gain due to a constant need to counter hypoglycemia. In addition to an extensive review of the literature, we report the first case of an insulinoma coexisting with reduced appetite secondary to anorexia nervosa in an adolescent female.
Eliciting a detailed family history is important in hypoglycemia cases.
Obtaining a thorough dietary intake, weight history, and menstrual cycles (in females) and considering a psychiatric consultation for an eating disorder when indicated.
Although rare in the pediatric population, multiple endocrine neoplasia type 1 syndrome should be considered in the evaluation of children and adolescents with hypoglycemia who also have a family history of pituitary, pancreatic, and/or parathyroid endocrinopathies.
We describe the clinical presentation, diagnostic and management issues in five cases of non-islet cell tumor hypoglycemia (NICTH), diagnosed at a tertiary care institute over a period of 15 years. The clinical, laboratory, and histopathological findings of these patients along with diagnostic utility of IGF2:IGF1 ratio are discussed. The mean age of presentation was 52 years, with a male predominance (3:2). Three patients presented with recurrent episodes of fasting hypoglycemia and it was detected in other two patients during hospitalization. Two patients had acromegaloid features that regressed following treatment. One patient had hypokalemia. Low levels of insulin, C-peptide, GH, and IGF1 were invariably found in all. The IGF2 level was elevated in only one patient; however, IGF2:IGF1 ratio was more than 10 in four of the five patients. The mean tumor size was 16.4 cm and mean weight was 3.6 kg. Four patients had mesenchymal tumors and one had epithelial tumor. NICTH is a rare cause of hypoglycemia. Hypoinsulinemic hypoglycemia with low IGF1 and IGF2:IGF1 ratio more than 10 is suggestive of this entity.
NICTH should be considered in patients presenting with tumor of mesenchymal origin and hypoglycemia.
Hypoinsulinemic hypoglycemia with low IGF1 is a strong biochemical evidence of NICTH.
IGF2:IGF1 ratio of more than 10 is a complementary investigation in the absence of an assay facility for IGF2.