[Esophageal carcinoma with hypercalcemia that appeared to be caused by prostaglandin E2 produced by the tumor cells].

Discussed is the case of a 50-year-old man with a well advanced esophageal carcinoma who, during his final clinical course, suddenly developed hypercalcemia (max: 15.0 mg/ml). His serum parathyroid hormone level, however, remained within normal limits. On autopsy, an extensive metastasis to many organs and lymph nodes was noted but no evidence of a bone metastasis. Nude mice bearing the same tumoral tissue were found, on autopsy, to have similarly developed hypercalcemia and cells that were cultured were found to produce an excessive amount of Prostaglandin E2 (PGE2). These findings suggest that this humoral hypercalcemia of malignancy (HHM) was caused by excessive PGE2 produced by the tumor cells, although other possible factors should be investigated.