To the Editor.—
I read with interest the article by Tell and associates1 regarding the clinical usefulness of the immunoperoxidase technique for prostate-specific antigen in the diagnosis of atypical metastasis from prostate cancer. This excellent article again brought to our attention the value of special histochemical techniques. I would only like to add that atypical metastasis from prostatic carcinoma may also be confirmed using immunoperoxidase techniques on cytological specimens obtained by fine-needle aspiration. Use of this technique was reported by Reifler and associates2 in a case of orbital metastasis. Nadji3 also demonstrated the possibilities of concurrent application of immunoperoxidase techniques with diagnostic cytology, including the establishment of a prostate carcinoma in a cervical lymph node. Certainly, fine-needle aspiration does not exclude the use of immunoperoxidase techniques and should be considered in selected cases, when an open biopsy would involve an extensive surgical procedure.
Reifler DM. Immunoperoxidase in Fine-Needle Aspirate Specimens. JAMA. 1985;254(18):2553. doi:10.1001/jama.1985.03360180051010