[Acute hypercalcaemic crisis in the course of PTH-rP producing squamous cell carcinoma of the skin--a case report].

Hypercalcemia is one of the most common paraneoplastic syndromes, where it may result from the presence of osteolytic metastases or from humoral effect of factors produced by tumor cells. One of such factors is the parathyroid hormone-related protein (PTH-rP). This protein is usually produced by solid tumors, especially by squamous cell carcinomas. In the case of squamous cell carcinoma of the skin hypercalcemia is very rare and symptomatic hypercalcemia is unusual. We present a case of acute hypercalcemic crisis as a consequence of overproduction of PTH-rP in a patient with spinocellular squamous cell carcinoma of the skin, which was proved by immunohistochemical staining of the tissue samples from the neoplastic lesion, metastases in bone and in lung, and also from kidney and liver.