Rapid lump examination (RLE) - a new tool for Mohs surgery?

BACKGROUND: "Micrographic surgery" spares tissue and results in fewer recurrences. Various techniques have been described using paraffin-embedded and cryostat sections or even optical sections from ex vivo confocal laser scanning microscopy. The presented technique is the rapid direct microscopy of the surface of a specimen (lump) for a pathological examination (RLE). METHODS: Fresh surgical tissue was stained first without sectioning and then was examined directly under microscope. A 95 sec staining protocol for basal cell carcinoma (BCC) was established. 129 specimens were examined using a digital microscope and 78 specimens using a stereo microscope. RESULTS: RLE had a high diagnostic accuracy compared to paraffin-embedded H&E-stained sections. Sensitivity and specificity of RLE was 91 % and 90 % for the digital and 90 % and 94 % for the stereo microscope. In addition we developed a 7 min RLE-immunohistology protocol using the BerEp4-antibody. DISCUSSION: RLE is a simple and accurate technique for fresh tissue examination. Here, the technique has been established for BCC but the principle may also be transferred to histological bedside diagnosis of other tumors. The technique does not alter or destroy tissue, so that after RLE was done subsequent conventional histology is still possible. RLE might yield a time- and cost-saving diagnosis in micrographic surgery.

Confocal laser scanning microscopy vs 3-dimensional histologic imaging in basal cell carcinoma.

OBJECTIVE: To compare ex vivo confocal laser scanning microscopy (CLSM), which offers rapid images without the need for tissue processing, vs 3-dimensional histologic imaging, the criterion standard treatment for basal cell carcinomas in high-risk areas of the face. DESIGN: Single-center prospective trial. SETTING: Dermatosurgical unit of a university hospital. Patients Seventy-two consecutive surgically removed basal cell carcinomas were examined using CLSM vs standard paraffin-embedded 3-dimensional histologic imaging. Interventions A total of 312 images, including 73 midsections, 196 lateral margins, 23 "muffins," and 20 "bread loaf sections," were obtained using CLSM. Immediately after surgery, the CLSM images were evaluated by the surgeon. The following day, the 3-dimensional histologic slides were evaluated and compared with the CLSM images. MAIN OUTCOME MEASURES: Diagnostic accuracy of ex vivo CLSM to detect tumor strands of basal cell carcinomas and the practicality of using CLSM vs 3-dimensional histologic slides in micrographic surgery. RESULTS: The sensitivity of CLSM reached 94.0% in midsections, 73.7% in lateral margins, 80.0% in muffins, and 80.0% in bread loaf sections. The CLSM images were evaluated by the surgeon within 7.5 minutes. CONCLUSIONS: Confocal laser scanning microscopy lacks high sensitivity to detect small tumor strands of basal cell carcinomas. In the future, CLSM may represent a time-saving and less expensive alternative to cryostat histopathologic examination.