Retroperitoneal neurilemoma presenting with humoral hypercalcemia associated with markedly elevated plasma prostaglandin levels

Article Abstract:

Hypercalcemia is one of the more common complications of tumors. This excessive amount of calcium in the blood may arise in two ways. The growth of metastatic cancer in the bone itself may erode bone tissue, returning large amounts of calcium to the blood. Alternatively, the tumor may not be directly involved with the bone, but may secrete hormonal factors that influence the bone and elicit a return of calcium to the blood. The latter condition is called humoral hypercalcemia of malignancy (HHM). A key factor in cases of HHM is thought to be parathyroid hormone-related protein, a substance similar to parathyroid hormone which, under normal circumstances, stimulates the return of calcium to the blood when it is needed. A case study of a 72-year-old woman with hypercalcemia secondary to a tumor is presented, in which testing for parathyroid hormone-related protein proved negative, suggesting that this substance is not the only one that contributes to hypercalcemia in tumor patients. The woman had developed somnolence, thirst, fatigue, and pain in both knees. CT scans revealed a 3-centimeter tumor next to the lower spine that was found to a benign neurilemoma, a tumor of the cells forming the sheath of peripheral nerves. Laboratory tests revealed severe hypercalcemia, which was deemed to be responsible for her symptoms. The laboratory analysis also revealed increased amounts of prostaglandins and related compounds in the patient's blood plasma, including increased amounts of thromboxane B2, prostaglandin E2, 6-keto prostaglandin F1 alpha, and prostaglandin F2 alpha. The patient's tumor was successfully removed surgically, and both the severe hypercalcemia and prostaglandin levels returned to normal, indicating that the tumor itself was causing the hypercalcemia by hormonal influences. Chemical analysis of the tumor did not, however, reveal the parathyroid hormone-related protein that had been expected. The authors speculate that the tumor secreted some unknown factor, which stimulated the secretion of prostaglandins. Among the many tissues that may have participated in this secretion of prostaglandins is bone tissue. Perhaps the secretion of prostaglandins by bone stimulated the resorption of bone calcium in this patient. (Consumer Summary produced by Reliance Medical Information, Inc.)

Case studies, Prostaglandins, Nervous system tumors

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Hypercalcemia in patients with esophageal carcinoma: the pathophysiologic role of parathyroid hormone-related protein

Article Abstract:

Paraneoplastic syndromes are complications of cancer that result not from the direct effects of the tumor mass, but rather from metabolic and hormonal effects of the tumor. The most common paraneoplastic syndrome is hypercalcemia. The level of calcium in the blood is elevated in about nine percent of all cancer patients. Researchers have evaluated 382 consecutive patients with esophageal cancer and found that 1.3 percent had hypercalcemia at the time of their initial diagnosis. Among patients within two months of death, it was found that 45 of 120 (38 percent) had hypercalcemia. This indicates that hypercalcemia is particularly frequent as a paraneoplastic complication of esophageal cancer. In 36 patients with hypercalcemia, the increase in calcium in the blood serum could not be explained by the presence of metastatic cancers in the bone, and therefore these cases were considered to result from some hormonal effect of the tumor. One hormone that influences the level of calcium in the blood is parathyroid hormone, which under normal circumstances will reclaim calcium from bone tissue to prevent the blood calcium level from falling too low. However, recently, a similar but distinct hormone with similar effects has been discovered; it is known as parathyroid hormone-related protein (PTHrP). This hormone can induce the elevation of calcium in the blood under experimental conditions. When tumor specimens from the patients were extracted, the amount of PTHrP could be measured using an antibody assay. It was found that the amount PTHrP in the tumor was correlated with the patient's hypercalcemia. Furthermore, the methods of molecular biology were used to demonstrate that the tumor cells were producing the messenger RNA necessary for the synthesis of PTHrP. These observations suggest that parathyroid hormone-related protein released by esophageal cancer cells may be responsible for the hypercalcemia observed in these patients. (Consumer Summary produced by Reliance Medical Information, Inc.)

Complications and side effects, Hormones

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Superficial esophageal carcinoma: surgical treatment and the results

Article Abstract:

Improvements in endoscopy have resulted in a greater number of esophageal cancers being diagnosed when they are still superficial, that is, the cancerous invasion has gone no further than the submucosal layers (just below the mucous membrane). In Japan, the proportion of esophageal cancers diagnosed in the superficial stage has risen from 5.7 percent in 1977 to 12.9 percent in 1982. Despite this increase, few data are available that describe the clinical features of the disease and the prognosis after surgical treatment. The authors report their experience with 92 patients with superficial esophageal cancer. All patients were treated surgically, but the details of the operation were dependent upon the location, size, and distribution of the cancerous lesions. Five patients died of complications resulting from surgery. Examination of the surgical specimens revealed that the cancer was limited to the mucosa in 24 patients, and had invaded the submucosal layer in 68 patients. Among the 24 patients with only mucosal involvement, 23 did not have metastatic spread to the lymph nodes. In contrast, only 65 percent of the patients with submucosal cancer were free of lymph node metastases. The invasion of the submucosa was a significant prognostic indicator; 83.5 percent of the patients with only mucosal involvement were alive after five years, while only 54.9 percent of patients with submucosal invasion survived. The results suggest that esophagectomy with removal of lymph nodes is necessary for patients with superficial esophageal carcinoma invading the submucosal layer. However, for patients with cancer that is limited to the mucosa, it may be possible to use more conservative treatment. (Consumer Summary produced by Reliance Medical Information, Inc.)

Prognosis, Surgery, Cancer

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