Localized insulin amyloidosis with use of concentrated insulin: a potential complication

BACKGROUND

Insulin-derived amyloidosis is a rare form of amyloidosis composed of insulin fibrils. The pH and concentration of insulin are known to influence the conformational state of the insulin hormone, with an increasing concentration favouring a more complex conformation. Concentrated insulin delivers a large amount of insulin to a localized area, raising the possibility of inducing conformational changes, forming insulin fibrils and leading to localized insulin amyloidosis.

CASE REPORT

A middle-aged woman with long history of Type 2 diabetes mellitus, treated with concentrated human insulin (U-500 insulin) presented with nodular lesions at the site of her daily insulin injections. A punch biopsy of the nodules showed skin with dermal amyloidosis staining favourably with Congo Red stain. The amyloid tumours were resected and areas positive for Congo Red stain were sent for liquid chromatography tandem mass spectrometry, which showed a peptide profile consistent with amyloid insulin.

CONCLUSION

Concentrated insulin was first introduced in 1952, however, it is only over the last two decades that it has been used increasingly, in congruence with the increasing incidence of obesity and diabetes mellitus seen in the USA. Only a few cases of insulin amyloidosis at the site of injection have been described in literature. With the increase in the use of insulin, this complication seems to be occurring more frequently. This is the first case report of a person with diabetes mellitus who developed localized insulin amyloidosis with the use of concentrated insulin, and points towards a potential complication of developing insulin amyloidosis with the use of concentrated insulin.

Sonographic findings in Nicolau syndrome following intramuscular diclofenac injection: a case report

Nicolau syndrome (also known as embolia cutis medicamentosa and livedoid dermatitis) is a rare but severe localized adverse drug reaction of intramuscular injection of various drugs. The typical presentation is pain around the injection site soon after injection, followed by erythema, livedoid patch, hemorrhagic patch, and finally necrosis of skin, subcutaneous fat, and muscle tissue. We report a case that occurred in a 34-year-old woman after intramuscular injection of diclofenac sodium. Sonography showed diffuse thickening with increased echogenicity of the skin and subcutaneous fat layer, while MRI revealed extensive edema involving gluteal and piriformis muscles and deep fascia, and fluid collection.

Subcutaneous nodules at the injection site of low-molecular-weight heparin: a mimic of metastatic disease at CT

PURPOSE

To describe the appearance and prevalence of subcutaneous nodules in the anterior abdominal wall seen at CT in cancer patients receiving subcutaneous injections of low-molecular-weight heparin (LMWH).

METHODS

CT examinations were reviewed in 426 patients receiving subcutaneous abdominal wall injections of LMWH for the presence of nodules. Nodules were evaluated for contour, maximal diameter, CT attenuation, and presence of hazy changes or air in the surrounding fat.

RESULTS

Fourteen (3%) of the 426 patients had nodules attributable to subcutaneous injections of LMWH. Findings included poorly defined borders (100%), adjacent hazy soft tissue changes (100%), adjacent air (57%), and a mean CT attenuation of -4.4 HU (range: -50-40 HU). Three (0.7%) of 426 patients had nodules caused by metastatic disease. One (33%) nodule had poorly defined borders, two (67%) had surrounding hazy changes, one (33%) had air in adjacent tissue, and there was a mean CT attenuation of 44 HU (range: 14-140 HU). One (0.2%) patient had a subcutaneous nodule of uncertain etiology.

CONCLUSION

Patients receiving subcutaneous injections of LMWH may develop nodules at the injection sites. Such nodules can resemble metastatic tumor deposits at CT, and careful correlation with clinical history and growth trends of metastatic deposits elsewhere in the patient is needed to avoid misdiagnosis.

[Acral necroses after therapy with quinine sulfate for calf cramps]

The most common cause of acral cyanosis is vascular spasm which can be induced by several drugs. An 87-year-old woman developed red and livid skin lesions on the fingers of both hands and several toes one month after beginning treatment with quinine sulfate 200 mg daily. The skin lesions progressed to necrosis in some areas. Quinine sulfate is a widely prescribed drug for nocturnal cramps. The following side effects may develop, particularly in the elderly: exanthems, pruritus, urticaria, erythema multiforme, purpura and photosensitivity. Our case points to the possibility of acral necrosis and demonstrates the efficacy of vasodilator treatment.

Hepatic falciform artery: anatomy, angiographic appearance, and clinical significance

Three patients developed supraumbilical skin rashes during hepatic artery infusion chemotherapy by a surgically placed perfusion catheter and drug-infusion pump. In one patient, hepatic arterial scintigraphy with technetium-99m macroaggregated serum albumin showed increased uptake corresponding to the rash, and a hepatic arteriogram showed a dilated falciform branch of the left hepatic artery. Surgical ligation of the falciform artery permitted further treatment without recurrent rash. Based on a review of 100 celiac arteriograms, the incidence of the falciform artery on angiographic studies is approximately 2%. The angiographic appearance of this artery is presented, and its potential clinical significance in hepatic artery perfusion chemotherapy is discussed.