Pathology/Lab Coding Alert

Question: Our pathologist reports the following diagnosis for a diagnostic cervical Pap smear: Low-grade squamous intraepithelial lesion (CIN I, mild dysplasia) with cellular changes. Which ICD-9 code(s) should we report -- 795.03 or 622.11 or both?

Massachusetts Subscriber

Answer: You should report 795.03 (Papanicolaou smear of cervix with low grade squamous intraepithelial lesion [LGSIL]).

Your confusion stems from the fact that in addition to stating LGSIL, the pathologist lists CIN I and mild dysplasia in parenthesis. The pathologist might mention all of these terms because different classification systems exist for describing cervical cellular changes. For the type of changes your pathologist notes in this case, three distinct classification systems use different terminology as follows:

• World Health Organization (WHO) -- Mild dysplasia

• Cervical Intraepithelial Neoplasia (CIN) -- CIN I

• Bethesda system -- Low-grade squamous intraepithelial lesions.

CPT is different: Although all three above descriptions may be fairly equal from a clinical perspective, they are not equal from a CPT coding perspective. Because 795.00-795.09 (Abnormal Papanicolou smear of cervix and cervical HPV) describe abnormalities in a cervical Pap smear specimen, you should use these codes to describe abnormal Pap results. These codes use the Bethesda system terminology, but you should use 795.0x for abnormal Pap results even if the pathology report uses other classification nomenclature.

Here's why: Pap tests are based on evaluation of cells (cytology), while a firm diagnosis for precancerous or cancerous cervical changes requires evaluation of tissue (histology). Although you'll find the "dysplasia" (WHO) and "CIN" terminology in other ICD-9 codes such as 622.1x (Dysplasia of cervix [uteri]) or 233.1 (Carcinoma in situ of cervix uteri, CIN III), you should use those codes only when the pathologist diagnoses a tissue specimen (histology).

How do you know this? A note under 622.1 explains the distinction: "Excludes abnormal results from cervical cytologic examination without histologic confirmation (795.00-795.09)."

Do this: In other words, for a diagnosis of low-grade squamous intraepithelial lesion (CIN I, mild dysplasia) with cellular changes, you should report 795.03 if the specimen is a diagnostic Pap smear, but you should list 622.11 (Mild dysplasia of cervix, CIN I) if the specimen is tissue, such as a cervical biopsy.