Multimodality Treatment of Neuroendocrine Tumors of the Thymus

BACKGROUND

Neuroendocrine tumors of the thymus are rare neoplasms. Four patients with this tumor who underwent multimodality treatment are presented and the literature is briefly reviewed.

METHODS

The medical records of all patients treated for neuroendocrine tumors of the thymus from 1979 to 2002 were reviewed. Tumors were classified using a slight modification of the World Health Organization criteria.

RESULTS

The patients' median age was 38 years. All patients underwent extensive excision of the tumor. Histological diagnosis was atypical carcinoid (2), typical carcinoid (1), and small cell carcinoma (1). All patients developed recurrence(s). One patient died 132 months after diagnosis. The remaining three patients are alive with no symptoms at 135, 99, and 35 months, respectively, after diagnosis. Two patients with recurrences have been on treatment with Octreotide LAR with satisfactory results. One patient is free of disease.

CONCLUSIONS

Neuroendocrine tumors of the thymus are potentially aggressive tumors. Radical resection is the treatment of choice. The encouraging results obtained by administration of Octreotide LAR in two of our patients warrant further investigation.

Correction of hyperglycemia with phlorizin normalizes tissue sensitivity to insulin in diabetic rats

Insulin resistance is characteristic of the diabetic state. To define the role of hyperglycemia in generation of the insulin resistance, we examined the effect of phlorizin treatment on tissue sensitivity to insulin in partially pancreatectomized rats. Five groups were studied: group I, sham-operated controls; group II, partially pancreatectomized diabetic rats with moderate glucose intolerance; group III, diabetic rats treated with phlorizin to normalize glucose tolerance; group IV, phlorizin-treated controls; and group V, phlorizin-treated diabetic rats restudied after discontinuation of phlorizin. Insulin sensitivity was assessed with the euglyemic hyperinsulinemic clamp technique in awake, unstressed rats. Insulin-mediated glucose metabolism was reduced by approximately 30% (P less than 0.001) in diabetic rats. Phlorizin treatment of diabetic rats completely normalized insulin sensitivity but had no effect on insulin action in controls. Discontinuation of phlorizin in phlorizin-treated diabetic rats resulted in the reemergence of insulin resistance. These data demonstrate that a reduction of beta-cell mass leads to the development of insulin resistance, and correction of hyperglycemia with phlorizin, without change in insulin levels, normalizes insulin sensitivity. These results provide the first in vivo evidence that hyperglycemia per se can lead to the development of insulin resistance.

Biliary obstruction after gastrectomy for carcinoma of the stomach

Extrahepatic biliary obstruction occurred in 34 patients after 1,300 gastrectomies performed for carcinoma of the stomach. Metastasis to the portal nodes caused mainly by distal gastric neoplasms is the most common cause of extrahepatic biliary obstruction. The syndrome of severe unrelenting bilirubinemia with abdominal aches and a palpable liver signifies extrahepatic biliary obstruction until proved otherwise and calls for early exploration. Palliative operation can prolong survival if properly performed. Selection of the proper procedure requires operative cholangiograms. Pancreatoduodenectomy is the most successful palliative procedure. Prevention of extrahepatic biliary obstruction requires a meticulous dissection of the portal pedicle during radical gastrectomy.

Experimental use of a gastric flap on an omental pedicle to close defects in the trachea, pharynx, or cervical esophagus

The use of local or regional skin flaps for repairs after head and neck cancer surgery often increases the deformity of the patient. We present a new procedure using a gastric flap on an omental pedicle. It has been successful in dog experiments where we transferred it to the head and neck region, to serve as a substitute for the standard skin flaps.

Comparison of lymphedema following incontinuity and discontinuity groin dissection

Wide excision of primary malignant melanoma en bloc with regional lymphadenectomy decreases the incidence of regional recurrence as compared with a discontinuous dissection. The more extensive soft tissue defect of the incontinuity procedure is of concern since major lymphatics are often ablated from the ankle region up to the aortic bifurcation. This problem was studied in 81 currently living patients, all of whom had been operated upon for primary melanoma located below the distal thigh. Measurable lymphedema was found in 64% who had had the incontinuity procedure and 69% in the discontinuity group. The incidence of advanced lymphedema (greater than two inches) was 23% and 36%, respectively. All patients with advanced edema had been operated upon more than 3 years ago. Eighty per cent of patients operated upon more than 5 years ago had lymphedema. Wound complications had occurred in 41% of the patients in the incontinuity group and 42% in the discontinuity group, but this did not affect the incidence of edema. The clinical findings are readily explainable on the basis of lymphangiographic data.

Prediction of intestinal viability by intra-arterial dye injection: a simple test

A vital dye solution injected intra-arterially stains only the viable parts in intestine of questionable viability. After various periods of ischemia, the viability of rat intestinal loops was assessed by three methods: on clinical basis; by detection of reactive hyperemia using an electronic thermometer; and by intra-arterial dye injection. The accuracy in viability prediction was 36, 69, and 84 per cent, respectively. The intraarterial dye injection method proved to be a simple, easy, and inexpensive way to accurately predict the viability of ischemic rat intestine.