Frozen sections of bone biopsies in metabolic and other bone diseases

Can the inferior alveolar nerve be used as a marker in frozen section for free margin control after segmental mandibulectomy in tumour ablation?

This study critically assessed the possibility of tumour spread along the inferior alveolar nerve (IAN) and its sensitivity as an intraoperative marker for clear bony margin control in frozen section during segmental mandibulectomy. Fifteen patients with oral squamous cell carcinoma (OSCC) involving the mandible and requiring a segmental mandibulectomy were included in this prospective trial. The ends of the IAN were analyzed using quick section analysis and the results compared with those of the definite pathological report. Nerve tissue could be identified in 25 of the 27 specimens collected. No specimen revealed tumour invasion. All histological diagnoses were finally confirmed. Three positive bony margins with microscopic carcinoma infiltrates were found, whereas corresponding nerve tissue did not confirm tumour invasion. This study supports the assumption that the pattern of tumour invasion is rarely primarily along the IAN in OSCC involving the mandible. Quick section analysis of the nerve tissue alone is therefore not a valid marker for intraoperative bony margin control. However, it can be used as an additional intraoperative diagnostic tool combined with other methods in rare cases of primary tumour spread along the IAN. A review of current knowledge regarding bony margin control published in the literature is provided.

Intraoperative Evaluation of Cortical Bony Margins with Frozen-Section Analysis

OBJECTIVES: To describe and evaluate the efficacy of frozen-section analysis of cortical bone margins in surgery of the craniofacial skeleton.

STUDY DESIGN: Retrospective analysis of a consecutive series of patients undergoing oncologic resection of various head and neck neoplasms with osseous involvement by the senior author (Y.D.) from 1998 to 2003.

RESULTS: Frozen-section analysis of cortical bone was performed in 38 patients. Adequate specimens for histological analysis were obtained in all patients. Frozen sections were positive in 21 of 22 patients with bone invasion on decalcified specimens. After validating our technique for frozen analysis of cortical bone in 13 patients, the method had a sensitivity of 89% and a specificity of 100% in 25 patients. Malignancies diagnosed on frozen cortical bone specimens included squamous cell carcinoma (15), mucoepidermoid carcinoma (3), and sarcoma (3). Frozen cortical margins altered the extent of bony resection in 8 patients.

CONCLUSION: A simple technique for analysis of cortical bone involvement by neoplasm is presented and reviewed. It allows for frozen-section analysis with standard equipment and appears to be a reliable method to evaluate bony margins intra-operatively.

EBM rating: C-4

Producing frozen sections of calcified bone

We describe a procedure for the rapid production and maintenance of fresh frozen bone biopsies which can be used for a variety of immunohistochemical techniques. Within 5 min of excision, tissue is placed in cold 5% polyvinyl alcohol, surrounded with 3% carboxymethylcellulose in a hand made aluminum foil embedding mold and frozen by immersion in an absolute ethanol/dry ice slurry at -70 C. The tissue block is attached to the specimen stub with cryocompound and installed in a -32 C cryostat whose tungsten carbide D profile knife is maintained at -70 C. Automatic controls are set at a slow cutting speed and the "sectioning window" is adjusted to fit the biopsy size. Knife angle, thickness gauge and antiroll bar are changed to produce a complete section. The block face is smoothly "papered" with a polyvinylpyrrolidone (PVP) impregnated Ross lens paper strip. A single section is cut and positioned on a sequentially numbered, acid cleaned, double dipped chrome-alum gelatin coated slide; adhesion is aided by "press-blotting" with bibulous paper. Sections are stored at -20 C or in a desiccator at room temperature. A brief fixation followed by removal of the water soluble PVP and lens paper generates fresh frozen bone sections suitable for further analysis.

Histomorphometry of fresh frozen iliac crest bone biopsies

Although methods are well established for the rapid histological preparation of fresh frozen soft tissues, they remain inadequate for the preservation of hard tissues. A recent technique for sectioning fresh frozen bone, in which sections can be prepared within an hour, has been applied to undecalcified human iliac crest bone biopsies. Quantitative analysis has shown that the static remodeling variables deduced from frozen sections closely resemble those derived from plastic-embedded sections prepared for routine use by established laboratory procedures. It is concluded that the rapid method is reliable for immediate diagnostic and histomorphometric purposes.