Frozen section biopsy: Procedure, applications, and key benefits

1. What is frozen section biopsy?

Frozen section biopsy is a rapid histopathological diagnostic technique performed during surgery. It enables the prompt determination of the nature of a lesion through specialized tissue processing.

Definition: Frozen section biopsy, also known as a frozen section, is an urgent histopathological examination performed during surgery. The tissue sample obtained from the patient is rapidly frozen, cut into very thin sections, and stained for microscopic examination. Its primary purpose is to provide a preliminary diagnosis of the lesion (benign or malignant), assess surgical margins, or identify the presence of a lesion as quickly as possible, usually within 10–20 minutes [2].
History and development: Frozen section biopsy has undergone significant development. The technique was introduced in 1905 and revolutionized surgical practice [3]. From its early, relatively rudimentary methods, frozen section biopsy has evolved with the introduction of modern cryostats, which have made tissue freezing and sectioning more precise and efficient [2]. Today, frozen section biopsy is an integral part of anatomical pathology practice, particularly at major medical centers such as University Medical Center Ho Chi Minh City.

2. The frozen section biopsy procedure

The frozen section biopsy procedure involves several key steps, from specimen preparation and freezing to sectioning, staining, and interpretation. It requires close coordination among healthcare professionals.

Specimen preparation: Once the surgeon obtains the tissue sample requiring diagnosis, it is immediately transported to the anatomical pathology laboratory. Prompt delivery is essential to preserve specimen quality. The surgeon must also provide complete clinical information and specify the sampling site to support the pathologist’s diagnostic assessment.
Freezing the specimen: The fresh tissue specimen is placed on a specimen holder and rapidly frozen using a cryostat, a device capable of reaching very low temperatures, typically around −20°C to −30°C. Rapid freezing helps preserve cellular and tissue structures and prevent degradation.
Sectioning and staining: Once frozen, the tissue becomes firm enough to be cut into very thin sections, approximately 4–6 micrometers thick, using the cryostat blade. These sections are then placed on glass slides and rapidly stained, usually with hematoxylin and eosin (H&E), to highlight cellular and tissue structures.
Interpretation and diagnosis: The pathologist examines the stained sections under a microscope. Drawing on their expertise and experience, they assess cellular structures and tissue morphology to establish a preliminary diagnosis. The result is communicated to the surgeon immediately by telephone or an internal communication system, usually within 10–20 minutes of specimen receipt [2].

3. Applications of frozen section biopsy in medicine

Frozen section biopsy plays an essential role in medicine, particularly in oncologic surgery. Its applications help guide clinical decisions during an operation.

Determining whether a lesion is benign or malignant: This is one of the most common applications. If a tumor or suspicious lesion is identified during surgery, frozen section examination can help determine whether it is benign or malignant. The findings guide the surgeon in deciding the extent and approach of further surgery [2].
Assessing surgical margins in cancer surgery: When removing a malignant tumor, it is important to ensure that all cancer cells have been removed. Frozen section examination can be used to assess the surgical margins of the specimen. If cancer cells are detected at a margin, the surgeon may decide to remove additional tissue to achieve clear margins and reduce the risk of recurrence [5].
Confirming the presence of a lesion: In some cases, the surgeon needs to confirm whether the collected tissue contains the target lesion, particularly when the lesion is very small or difficult to identify with the naked eye.
Ensuring sufficient tissue for specialized tests: Frozen section examination can help confirm that enough tissue has been obtained for subsequent additional tests, such as immunohistochemistry and molecular testing, which may require fresh tissue or specially processed specimens.
Detecting lymph node metastasis: In cancer surgery, determining whether cancer has spread to nearby lymph nodes is important. Frozen section examination may be used to rapidly assess sentinel lymph nodes or suspicious lymph nodes [2].
Supporting specific procedures, such as parathyroid surgery: During parathyroid surgery, frozen section examination can help confirm whether the excised tissue is parathyroid tissue, particularly when distinguishing it from adipose tissue or thyroid tissue, thereby helping ensure that the intended surgical objective is achieved.

4. Key benefits of frozen section biopsy

Frozen section biopsy offers several important benefits that can improve treatment outcomes and patients’ quality of life.

Rapid diagnosis during surgery: The ability to provide diagnostic results within minutes is one of the greatest advantages of frozen section biopsy. It gives surgeons the information they need to make immediate decisions without waiting several days.
Timely guidance for surgical decisions: Based on the frozen section results, surgeons can modify the surgical plan immediately, for example, by removing additional tissue, performing lymph node dissection, or even stopping further surgery if the tumor is benign and no additional intervention is required.
Reducing the need for repeat surgery: If the nature of the tumor or the status of the surgical margins is determined during the initial operation, patients may avoid a second procedure to complete treatment, reducing both physical and emotional burdens [2].
Optimizing treatment outcomes: Accurate and timely decisions help optimize treatment effectiveness, particularly in cancer care, where each decision can affect the patient’s prognosis.

5. Limitations and considerations of frozen section biopsy

Although frozen section biopsy is a useful technique, it has certain limitations and requires careful consideration to ensure diagnostic accuracy and safety.

Sampling errors: If the tissue sample is not representative of the entire lesion—for example, if only the benign portion of a malignant tumor is sampled—the diagnosis may be inaccurate.
Technical issues (freezing artifacts and section quality): Rapid freezing can produce ice crystals that distort cellular or tissue structures, creating artifacts that affect the pathologist’s ability to interpret the specimen [4]. Frozen sections may also be less uniform in quality than paraffin-embedded sections.
Interpretation errors: Frozen section diagnosis requires considerable expertise because the tissue sample may not be as optimal as one prepared using routine histopathological processing. Difficult or rare cases may result in an inaccurate diagnosis or require additional time for confirmation [4].
Diagnostic accuracy and influencing factors: Frozen section biopsy generally has high diagnostic accuracy, but a small proportion of cases may show discrepancies compared with the final diagnosis from routine histopathological examination. Factors affecting accuracy include the size and type of lesion, the experience of the personnel involved, and the complexity of the case [4].

6. Comparing frozen section biopsy with other rapid diagnostic methods

In addition to frozen section biopsy, several other histopathological and cytological methods are available. Comparing these techniques helps highlight their respective advantages and limitations and supports the selection of the most appropriate method for each clinical situation.

Routine histopathological examination (paraffin-embedded tissue technique): Routine histopathological examination is the gold standard for histopathological diagnosis. Tissue is fixed in formalin, processed through several steps, embedded in paraffin, sectioned, and stained. This process takes several days but produces high-quality tissue sections with minimal distortion that can be preserved for long periods. Frozen section biopsy provides results more quickly, but tissue quality may be inferior.
Intraoperative cytology: This method involves collecting cells from a lesion by scraping or aspiration, smearing them onto glass slides, and staining them for microscopic examination. Intraoperative cytology also provides rapid results and is often used as an adjunct to frozen section biopsy, particularly when frozen sections are difficult to interpret. However, it provides information about individual cells rather than tissue architecture, which may make it more difficult to distinguish benign from malignant lesions or assess surgical margins.
Fine-needle aspiration cytology (FNAC): FNAC is a minimally invasive cytological diagnostic technique commonly performed before surgery to assess palpable masses or lesions identified through imaging guidance. It also provides rapid results but is not an intraoperative diagnostic method.

7. The future of frozen section biopsy

With continuous advances in science and technology, frozen section biopsy is expected to continue evolving through the integration of new technologies that improve diagnostic accuracy and efficiency. Future developments may involve combining frozen section examination with modern technologies. Artificial intelligence (AI) is being investigated as a tool to assist pathologists in analyzing frozen section images, with the potential to improve diagnostic accuracy and speed [1]. Advanced imaging techniques and new staining methods may also help improve specimen quality and diagnostic capabilities.

8. Frequently asked questions (FAQ)

Below are some frequently asked questions about frozen section biopsy, with detailed answers to help readers better understand the technique.

Is frozen section biopsy accurate? Frozen section biopsy has high diagnostic accuracy, generally exceeding 95%, although a small proportion of cases may not fully agree with the final results of routine histopathological examination. Accuracy depends on several factors, including the type of lesion, the pathologist’s experience, and specimen quality [4].
When is frozen section biopsy necessary? Frozen section biopsy is generally indicated when a rapid diagnosis is needed during surgery, such as to determine the nature of a tumor, assess surgical margins in cancer surgery, or confirm the presence of the target tissue [2].
Is frozen section biopsy painful? The frozen section examination itself does not cause pain because it is performed on tissue that has already been removed from the patient during surgery, which is usually performed under anesthesia.
Can frozen section biopsy results be incorrect? Yes. Although uncommon, results may be inaccurate because of technical factors such as freezing artifacts, sampling errors, or interpretation difficulties in complex cases [4]. When the findings are uncertain, the pathologist may recommend waiting for the results of routine histopathological examination.
How long does it take to receive frozen section biopsy results? Results are generally available within 10–20 minutes after the tissue specimen arrives at the anatomical pathology laboratory [2].

9. References

[1] Gorman, B. G. (2023). Artificial intelligence and frozen section histopathology. PubMed. https://pubmed.ncbi.nlm.nih.gov/37394789/. Accessed: 2025-12-10.
[2] Jaafar, H. (2006). Intra-Operative Frozen Section Consultation. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC3347896/. Accessed: 2025-12-10.
[3] Mayo Clinic. (n.d.). 1905: Frozen section technique revolutionizes surgery. History of Mayo Clinic. https://history.mayoclinic.org/wp-content/uploads/2022/11/1905.pdf. Accessed: 2025-12-10.
[4] Švajdler, M. (2018). Frozen section: history, indications, contraindications and .... PubMed. https://pubmed.ncbi.nlm.nih.gov/30441964/. Accessed: 2025-12-10.
[5] Brender, E. (2005). Frozen Section Biopsy. JAMA Network. https://jamanetwork.com/journals/jama/fullarticle/202100. Accessed: 2025-12-10.

The information above is for reference purposes only and is not intended as medical advice. Please contact your doctor for detailed medical consultation.