Hypoglycemia caused by abdominal leiomyosarcoma

Hypoglycemia associated with a leiomyosarcoma of the small bowel

A patient with recurrent hypoglycemic episodes associated with a leiomyosarcoma of the small bowel is described. Fasting plasma insulin levels were consistently low and a subnormal insulin response to provocative stimuli (oral glucose and i.v. glucagon) was shown. After removal of the tumor, hypoglycemic episodes disappeared, fasting plasma insulin concentrations rose to normal values and insulin response to both OGTT and glucagon test was markedly enhanced. The possible mechanisms responsible for the hypoglycemia and the causes of subnormal insulin response to provocative stimuli are discussed.

Mesenchymal tumors associated with hypoglycemia: case report and review of the literature

Hypoglycemia secondary to malignant tumors is rare. Mesenchymal tumors of nonpancreatic origin are the most common tumors associated with the hypoglycemia syndrome, and the clinical features of 115 reported cases are reviewed. The major anatomic distributions of the tumors are thoracic (30%) abdominal (65%), and uncommon locations (less than 5%). Approximately 50% of the tumors were resectable (59 patients), and in 60% the surgical procedure was curative. In the remaining 40% local recurrence predominated related to site of tumor and presence of contiguous organ invasion. The application of multimodality adjuvant therapy for hypoglycemia associated mesenchymal tumors should be based on an understanding of the natural history of the tumor.

Spindle cell sarcoma of the pulmonary trunk: a case report with histochemistry and electron microscopy

A further case of a spindle cell sarcoma of the pulmonary trunk is reported, with extension to the pulmonary valve and lungs. Some spindle cells contained glycogen and their cell walls acid mucosubstances. Electron microscopy showed two types of cell. The more common were polyhedral with poorly arranged fibrils in the cytoplasm and an abundant fuzzy coat. About 5 per cent of the cells contained neurosecretory granules.

Ectopic insulin and Occam's razor: reappraisal of the riddle of tumour hypoglycaemia

The concept of ectopic insulin production is challenged on the basis of a review of 120 cases from the literature on extrapancreatic tumours associated with hypoglycaemia in which insulin or insulin-like activity were measured. No case met two or more of five criteria of ectopic hormone production. The evidence indicates that hypoglycaemia of extrapancreatic tumours cannot be attributed to insulin. In those rare cases in which plasma insulin was reported as high, pancreatic beta-cells could not be excluded as the source of insulin. Interestingly, many of these dubious cases had carcinoid histology. The review also points out a close association between some spindle-cell tumours and carcinoid tumours which may be relevant to discussion on the disputed origin of some "mesothelial" tumours. Nonsuppressible insulin-like activity (NSILA) consists of a number of factors mimicking insulin activity which compete with insulin or proinsulin for membrane receptors and may crossreact in bioassays, immunoassays, and receptor assays. The question of whether one or several of these substances may be responsible for extrapancreatic hypoglycaemia remains to be elucidated.