When a Pap smear result returns with the designation “DNR,” it signifies that the laboratory could not provide a conclusive reading for the cervical cell sample. Clinics often use “DNR” to mean “Did Not Read” or “Result Not Determined,” classifying the result as inadequate or unsatisfactory. The primary purpose of a Pap smear is to screen for precancerous changes on the cervix. A DNR result means the test failed to perform this screening function, requiring the screening process to be repeated.
Understanding “DNR” and Other Inadequate Results
A result coded as DNR is an unofficial term corresponding to the official laboratory designation of an “Unsatisfactory” or “Inadequate” specimen. This designation is defined by The Bethesda System for Reporting Cervical Cytology, which standardizes Pap smear findings into categories like Negative, Abnormal, or Unsatisfactory. The core message of an unsatisfactory result is that the sample quality was too poor for reliable interpretation by the cytotechnologist or pathologist.
The Bethesda System specifies criteria for a sample to be deemed “Satisfactory for Evaluation”; any sample failing these criteria is marked “Unsatisfactory.” Other terms that might appear on a report include “Insufficient Cellularity” or “QNS” (Quantity Not Sufficient). Regardless of the specific acronym, the test is considered a failure because it could not reliably screen for cervical epithelial abnormalities. This lack of information means the patient’s cervical health status remains unknown from that screening attempt.
Factors Leading to an Unsatisfactory Sample
The reasons a Pap smear sample is deemed unsatisfactory fall into two broad categories: issues with the collection of epithelial cells and factors that obscure the cells on the slide. The most frequent cause for rejection is a paucity of epithelial elements, also known as scant cellularity. For analysis to be adequate, a liquid-based cytology sample requires a minimum number of well-visualized squamous cells. If the collection technique was insufficient or the cells were poorly preserved, the lab cannot meet this minimum cellularity threshold.
Obscuring factors are the second common reason for an unsatisfactory reading, preventing the technician from clearly visualizing the collected cells. Excessive amounts of blood from the cervix or vagina can hide epithelial cells, making microscopic evaluation impossible. High levels of inflammation or mucus can similarly interfere with the analysis, as these materials may obscure more than 75% of the cells needed for a proper reading. In liquid-based Pap tests, the presence of foreign material, such as excessive lubricant used during the examination, can also cause unsatisfactory results.
Biological Factors
Specific biological factors can also contribute to an inadequate sample, particularly in certain patient populations. For example, individuals who are postmenopausal or taking hormone therapies may experience cervical atrophy, making it physically difficult to collect an adequate number of cells. Low estrogen levels or hormone use can cause cellular changes that result in a technically insufficient sample. The goal of the Pap smear is to obtain cells from the transformation zone of the cervix, and if this area is difficult to access or sample correctly, the chance of an unsatisfactory result increases.
Clinical Interpretation of an Inconclusive Pap Smear
An unsatisfactory or DNR result is fundamentally a statement about the sample quality, not a medical diagnosis of a disease or abnormality. It simply means the screening test itself was invalid, and does not mean the patient has cervical cancer or a high-grade lesion. While the immediate risk from an isolated unsatisfactory result is low, the screening goal—to detect potentially precancerous changes like LSIL or HSIL—was not achieved.
Because the Pap smear failed to provide necessary information, the possibility of a hidden abnormality remains. In modern screening protocols, the Pap smear is often performed concurrently with testing for high-risk Human Papillomavirus (hrHPV). If the Pap smear is unsatisfactory but the hrHPV test results are valid, the HPV status informs the patient’s immediate risk level. A negative hrHPV result provides reassurance, while a positive hrHPV result may prompt a more urgent follow-up, such as a colposcopy, to investigate the increased risk.
Necessary Follow-Up and Next Steps
The primary course of action following an unsatisfactory Pap smear is to repeat the test to ensure cervical screening is completed. Medical guidelines, such as those from the American Society for Colposcopy and Cervical Pathology, recommend repeating the Pap smear within a short window, usually two to four months. This retest window allows temporary obscuring factors, such as menstrual bleeding or infection-related inflammation, to resolve naturally.
Patients can take specific steps to improve the chances of a clear, satisfactory result on the retest. It is advised to avoid douching, using vaginal medications, or having sexual intercourse for 24 to 48 hours before the collection appointment. These activities can introduce foreign materials or temporarily increase mucus and inflammation, obscuring the epithelial cells needed for analysis. Rescheduling the test for a time when the cervix is not actively bleeding significantly increases the likelihood of obtaining a “Satisfactory for Evaluation” result.