Donald L. Gordon

Carcinoid of the pancreas

Abstract A patient is presented with carcinoid syndrome due to a pancreatic tumor. Histologically the tumor resembled a carcinoid, adenocarcinoma and islet cell carcinoma, depending upon the area examined. A review of the literature uncovered similar instances of confusion. By correlating the clinical, biochemical, histochemical and pathological findings, we conclude that our patients tumor was a primary pancreatic carcinoid.

Artifactual elevation of thyroid-stimulating hormone

A clinically euthyroid patient was found to have a normal serum thyroxine level and an elevated plasma thyrotropin (TSH) level measured by fluoroimmunoassay. Thyroid hormone therapy failed to suppress the TSH level. The TSH level was unresponsive to thyrotropin-releasing hormone (TRH) administration, alpha-subunits of pituitary glycoproteins were undetectable in her plasma, and imaging of the pituitary-hypothalamic region was normal. Measurement of TSH with an assay containing sheep antibody to TSH failed to reveal TSH in the patients plasma. Addition of mouse IgG to the TSH fluoroimmunoassay reduced the patients TSH to an undetectable level. These observations are consistent with a spurious elevation of TSH due to the presence of an anti-mouse antibody. Artifactual elevations of TSH have not been identified commonly, but this possibility should be considered when the TSH level is inappropriate for the apparent state of thyroid function.

The effect of fine-needle aspiration biopsy on the thyroid scan

Fine-needle aspiration biopsy (FNAB) is the most sensitive and specific procedure in diagnosing benign from malignant thyroid nodular disease. The effects of a FNAB on the thyroid scan, however, have never been studied. This assumes importance because a hot nodule on scan has been advocated as useful to differentiate certain benign from malignant follicular neoplasms. Thyrold scans were performed before and after FNAB on 11 patients with nodular thyroid disease and an area of normal or increased uptake either in the nodule or in a contralateral enlarged lobe to determine if the blopsy changed the pattern of isotope uptake. For this study, biopsies were done in the area of normal or increased uptake. In two patients, there was a reduction in isotope concentration in three nodules after FNAB, whereas no change was demonstrable in nine other patients. Review of the literature revealed a number of prior reports of hemorrhage, necrosis, or infarction of thyroid nodules after FNAB. Based on these data and the demonstration of a change in scan pattern in a patient following FNAB, it is concluded that FNAB may decrease the isotope uptake in thyroid nodules; therefore, the concept of clinical judgments being based on the scan pattern after FNAB should be reevaluated.

Immobilization-related hypercalcemia after renal failure in burn injury.

OBJECTIVE To describe a patient with hypercalcemia presumably due to immobilization in the setting of burn injury and acute renal failure. METHODS We present a case report of a man who sustained a severe burn injury and then had renal failure and hypercalcemia. An additional series of patients with burns and immobilization was assessed for the presence of hypercalcemia. RESULTS In a 43-year-old man with burns on 65% of his body surface area, acute renal failure developed. Renal function failed to return, and he continued to require hemodialysis. Because of the severity and extensiveness of his burns, he remained immobilized. Serum calcium levels were low during the early part of the hospitalization. On the 57th day, generalized tonic-clonic seizures developed, and he was found to have a high ionized calcium level (1.41 mmol/L). Low values were recorded for intact parathyroid hormone (2 pg/mL), 25-hydroxyvitamin D (5 ng/mL), and 1,25-dihydroxyvitamin D (4 pg/mL). Persistent and recurrent hypercalcemia eventually responded to pamidronate and calcitonin. Other than immobilization, we could identify no predisposing factors such as confounding illnesses or medications that could have caused the hypercalcemia. A review of serum ionized calcium levels in 50 consecutive patients admitted to a burn unit and immobilized for at least 20 days failed to reveal any episodes of persistent hypercalcemia. CONCLUSION In our patient with burns and renal failure, symptomatic hypercalcemia was most likely attributable to prolonged immobilization. As patients with catastrophic illnesses survive for longer periods, additional problems such as hypercalcemia from immobilization may occur.

A SPURIOUS MARKEDLY INCREASED SERUM ESTRADIOL LEVEL DUE TO AN IgA LAMBDA

OBJECTIVE To alert physicians about the potential for erroneous laboratory determinations of hormone levels and emphasize the need to assess the overall clinical situation as well. METHODS We present a case report of a woman with a dramatically increased serum estradiol (E(2)) level on radioimmunoassay and review the studies that led to the conclusion that this laboratory finding did not reflect her true estrogen status. RESULTS In a 41-year-old woman, an unnecessary surgical procedure was performed because of a falsely increased serum E(2) level and a unilateral ovarian mass. The markedly increased serum E(2) measured by radioimmunoassay was found to be attributable to an IgA lambda that bound to the 125 I-labeled tracer of the assay. CONCLUSION When repeatedly abnormal hormone levels and the clinical picture seem discrepant, use of a different assay method should be considered.