Confirmation of metastatic prostatic carcinoma to lung by immunohistochemistry

In recent years, immunoperoxidase staining of fine needle aspirates has been proposed. This study examines the use of immunoperoxidase staining of prostatic acid phosphatase and prostatic specific antigen in two cases where differentiation of prostatic carcinoma from other carcinomas manifesting as metastatic lesions is essential. The histologic differentiation of primary and metastatic disease, which has significant therapeutic and prognostic implications, has been enhanced by the use of immunoperoxidase staining. The presented cases demonstrate the ease with which immunoperoxidase staining can be done in a community hospital.