Question: The oncologist notes that a prostate biopsy reveals "high-grade prostatic intraepithelial neoplasia (PIN-III)." I can't find this in the neoplasm table. What is the correct diagnosis code? New York Subscriber Answer: For high-grade PIN III you should use 233.4 (Carcinoma in situ of breast and genitourinary system; Prostate). Although the neoplasm table in the ICD-9 manual's index does not offer enough information to help you choose 233.4 for PIN III, you will find a "PIN III" entry in the index itself. That entry points you to 233.4 PIN is a condition that involves microscopic changes in the epithelial cells. For PIN I and PIN II, which represent a lesser degree of cellular abnormality of the prostate, the index points you to 602.3 (Dysplasia of prostate). Notes under 602.3 state: Prostatic intraepithelial neoplasia I (PIN I) Prostatic intraepithelial neoplasia II (PIN II) Excludes: prostatic intraepithelial neoplasia III (PIN III) (233.4).