UNDIFFERENTIATED CARCINOMA IN THE CARDIOESOPHAGEAL JUNCTION WHICH PRODUCES PARATHYROID-HORMONE RELATED PROTEIN

A 68-year-old man with undifferentiated carcinoma occurring in the car dioesophageal junction accompanied by hypercalcemia is reported, The s erum level of parathyroid hormone-related protein (PTHrP) was remarkab ly elevated, Serum calcium and PTHrP levels decreased following chemot herapy, but this amelioration was temporary, He died of hypercalcemia, On autopsy, a significant amount of immunoreactive PTHrP was detected in the tumor tissue extract, and the tumor cells were stained strongl y positive for PTHrP by immunohistochemistry. This is the first case o f undifferentiated carcinoma in the gastrointestinal tract which demon strated hypercalcemia due to PTHrP produced by the malignant tumor.