Conditions associated with normal levels of prostate-specific antigen and elevation of prostatic acid phosphatase.

Thirteen cases are reported with normal levels of prostate-specific antigen and elevated prostatic acid phosphatase (PAP). Conditions that were associated with an elevated PAP were myeloproliferative syndromes (four cases), metastatic nonprostatic carcinoma (six cases), prostatic carcinoma (one case), tuberculosis with a concurrent lupus-like syndrome (one case), and osteomyelitis (one case). The inclusion of PAP in the initial investigation of cases with suspected prostatic disease results in a decreased specificity.