Elevated parathyroid hormone-related protein and hypercalcemia in a patient with cutaneous squamous cell carcinoma complicating hidradenitis suppurativa.

We have described the case of a patient with long-standing hidradenitis suppurativa in whom associated cutaneous squamous cell carcinoma developed; this was complicated by hypercalcemia. Serum PTH-RP levels were elevated to 14.8 pmol/L. This is the third case report of hypercalcemia associated with squamous cell carcinoma complicating hidradenitis suppurativa and the first in which an elevated serum PTH-RP level has been documented in cutaneous squamous cell carcinoma.