The aggressive surgical management of hypercalcemia due to ectopic parathormone production

Immunohistochemistry in Diagnostic Parathyroid Pathology

Pathologists are usually readily able to diagnose parathyroid tissues and diseases, particularly when they have knowledge of the clinical information, laboratory findings, and radiographic imaging studies. However, the identification of parathyroid tissue or lesions can be difficult in small biopsies, ectopic locations, supranumerary glands, and in some oxyphil/oncocytic lesions. Widely available immunohistochemical studies such as chromogranin-A, synaptophysin, keratin, parathyroid hormone, thyroglobulin, and thyroid transcription factor-1 can help in difficult cases. One of the most difficult diagnostic aspects faced by the pathologist in evaluating parathyroid is distinguishing between parathyroid adenoma, particularly atypical adenoma, and parathyroid carcinoma. Many markers have and continue to be evaluated for diagnostic utility, and are even beginning to be studied for prognostic utility. Single immunohistochemical markers such as parafibromin and Ki-67 are among the most studied and most utilized, but many additional markers have and continue to be evaluated such as galectin-3, PGP9.5, Rb, bcl2, p27, hTERT, mdm2, and APC. Although not widely available in many laboratories, a panel of immunohistochemical markers may prove most useful as an adjunct in the evaluation of challenging parathyroid tumors.

Renal cell carcinoma presenting with paraneoplastic hypercalcemic coma: a case report and review of the literature

We report a case of a 62-year-old woman with renal cell carcinoma (RCC) presenting with a hypercalcemia-induced coma. A laboratory evaluation indicated nonparathyroid-mediated hypercalcemia with an initial serum calcium level of 18.6 mg/dL. Our patient's parathyroid hormone (PTH)-related peptide level was undetectable. Initial imaging was negative, but PET scan identified a mass in the upper pole of the left kidney. Our patient underwent partial nephrectomy, and the mass was identified as RCC on final pathology. After surgery, her hypercalcemia resolved and PTH returned to normal limits. This case report describes a patient with RCC with the unusual presentation of hypercalcemic coma. We review the differential diagnosis of malignant hypercalcemia and the evaluation of hypercalcemia occurring with RCC. This case illustrates the need to carefully review and interpret all available data, especially when conventional testing in the work-up of hypercalcemia is unrevealing.

Management and prognostic significance of hypercalcemia in renal cell carcinoma

A retrospective study was conducted to evaluate the prognostic significance of hypercalcemia associated with renal cell carcinoma and the efficacy of different treatment modalities. Twenty-seven of 160 (16.8%) patients with renal cell carcinoma were found to have tumor-induced hypercalcemia: 24 had Stage IV disease, 1 Stage III disease, and 2 Stage I disease. There was no evidence of bone metastasis in 13 of 27 (48%) patients. A total of 89 episodes of acute hypercalcemia were treated: 36 episodes resulted in a complete response ([CR] calcium levels returning to normal), 24 partial response ([PR] calcium decrease greater than 1 mg/dL, but above normal) and 29 negligible response ([NR] calcium decrease less than 1 mg/dL) to treatment modalities used. One patient with Stage I disease and 3 with Stage IV disease underwent nephrectomies resulting in 2 CR and 1 PR. There was a complete response (CR) to mithramycin in 7 of 10 (70%) acute hypercalcemic episodes, to furosemide and mithramycin in 12 of 20 (60%), to steroids or furosemide and steroids in 3 of 7 (43%), to hydration in 4 of 13 (31%), and to furosemide in 7 of 25 (28%). The response rates to phosphates, indomethacin, and calcitonin were low but involved a small number of patients. Survival in 24 patients with Stage IV disease was 5-239 days (av 87.3 days). There was essentially no survival difference between patients who had an initial calcium elevation less than or greater than 13 mg/dL. We conclude that mithramycin is more effective in controlling acute hypercalcemia secondary to renal cell carcinoma than furosemide or hydration. Steroids appear to be effective but our experience was limited. Surprisingly, the degree of calcium elevation did not show a significant correlation with survival.

Humoral hypercalcemia due to squamous cell carcinoma of renal pelvis

We describe an unusual and rare case of humoral hypercalcemia due to Stage D squamous cell carcinoma of the renal pelvis in a patient with no evidence of bony metastases. The literature on humorally mediated hypercalcemia associated with epithelial tumors of the renal pelvis is reviewed.