Successful Long-term Treatment with Once-daily Injection of Low-dose Octreotide in an Aged Patient with Insulinoma

Abstract

The patient was an 83-year-old woman who was admitted to our hospital for evaluation and treatment of chronic hypoglycemia that was first identified 3 years earlier. Serum insulin and C-peptide levels were both elevated during hypoglycemia. Contrast abdominal computed tomography revealed a tumor in the body of the pancreas with blushing during the early phase, and insulinoma was diagnosed. The patient declined surgery because of advanced age, so treatment was started with octreotide, a somatostatin analogue. Hypoglycemia has been successfully controlled with low-dose, once-daily octreotide over 33 months. Few reports have described long-term octreotide administration for benign insulinoma. Moreover, this case is interesting from the perspective of hypoglycemic control using only low-dose, once-daily octreotide. Although somatostatin may induce hypoglycemia in insulinoma, treatment may be useful in patients who are not candidates for surgery, provided that careful monitoring is maintained.

Medical Treatment of Benign Insulinoma Using Octreotide LAR: A Case Report

“…In cases treated with long-acting octreotide formulation, plasma glucose levels were reported to remain within normal range. The elevation in plasma glucose levels is probably due to: 1) inhibition of insulin secretion not only from insulinoma cells but also from normal pancreatic beta cells, 2) normal beta cell function suppressed due to hypersecretion of insulin from the insulinoma, 3) the action of insulin receptors down-regulated due to chronic hyperinsulinemia, and 4) obesity due to hyperphagia resulting in insulin resistance [7].…”

“…The somatostatin analogue, octreotide, is known to suppress the secretion of insulin in healthy subjects as well as in some patients with insulinoma. Several studies have reported the usefulness of octreotide in patients with benign and malignant insulinomas [1][2][3][4][5][6][7]. However, as octreotide is a shortacting formulation, several subcutaneous injections per day are required for effective treatment.…”

A Case of Secretin-responsive Insulinoma with Low Serum C-peptide Levels

“…In conclusion, this case report emphasizes some unusual features of an insulinoma, including a positive [18] 14.7 8 Kajinuma et al [19] 12.1 20 Okada et al [20] 11.2 136 Our case (after surgery) 17.6 1 Insulinoma Smythe et al [21] 20.0 1 Katabami et al [22] 7.2 4 Gin et al [23] 6.3 8 Sakai et al [18] 6.1 1 Scarlett et al [24] 5.9 1 Saudek [25] 5.6 1 Gerbitz and Spelsberg [26] 5.0 5 Lebowitz and Blumenthal [27] 4.9 3 Kondo et al [28] 4.2 3 Service [29] 3.6 1 Ciavarella et al [30] 2.9 1 Turner and Heding [31] 2.0 2 Our case (before surgery) 2.0 1 insulin response to secretin and decreased C-peptide levels, of which clinicians should be aware. The diagnosis of insulinoma should not depend on some particular endocrinological tests and should be made comprehensively.…”

“…Service et al reported that insulinoma patients had C-peptide values at the end of the 72 h fasts greater than or equal to 0.20 nmol/mL (0.60 ng/mL); however, our case does not fulfill that criterion even before conducting the prolonged fasting test [12]. According to the data from the literature, the molar ratio of serum C-peptide to insulin is, in general, decreased in patients with insulinoma than normal subjects, while in our case the ratios were much lower (Table 2) [18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

Usefulness of the octreotide test in Japanese patients for predicting the presence/absence of somatostatin receptor 2 expression in insulinomas

“…The octreotide test has been reported to be useful for predicting the efficacy of treatment in patients with benign insulinomas [8][9][10]. However, reports describ-mia.…”