Frozen Section

A frozen section is a quick diagnosis made during surgery: the pathologist freezes a piece of tissue, cuts a thin slice and examines it within minutes so the surgeon can decide what to do next. It is a preliminary reading; the final diagnosis comes later from the permanent, paraffin-processed slides.

Origin

Freezing tissue to cut it quickly was tried in the late nineteenth century, and the method was made practical for surgery at the Mayo Clinic in the early 1900s. It has been a standard part of surgical pathology ever since.

Significance in Asbestos Context

Surgeons use frozen sections to confirm they have sampled the abnormal tissue, check whether margins are clear, or decide whether to go ahead with a larger operation. Frozen tissue is harder to read than permanent sections, and mesothelioma can be particularly difficult: the frozen reading may say only "malignant cells" or "atypical mesothelial cells, defer to permanents." For that reason the operative report and frozen section note can differ from the final pathology report, which is not an error. In a claim, the final report, supported by immunostains, is the diagnosis that counts, but the frozen section record helps show what was known on the day of surgery. The leftover frozen tissue is usually processed into a paraffin block too, so it remains available for later review.

Example Sentence

The frozen section during her thoracoscopy read "malignant, favor mesothelioma," and the permanent sections with immunostains confirmed epithelioid mesothelioma.

Related Terms

Pathology Report, Paraffin Block, Thoracoscopic Biopsy, Video-Assisted Thoracoscopic Surgery (VATS), Immunohistochemistry, Histopathology, Surgical Resection

Notes

• Ask for both the operative report and the final pathology report; the final report is the one that counts.
• Do not be alarmed if the frozen section and final diagnosis use different words; ask your doctor to explain.
• Keep copies of all pathology reports from each surgery.