Mohs Tissue Mapping and Processing

Abstract

BACKGROUND Mohs micrographic surgery (MMS) is the most reliable, conservative, and tissue-sparing approach to the management of cutaneous malignancies. The concept of MMS is simple, but its technique, which involves a series of suboperations, is complex. OBJECTIVE To define which techniques of Mohs tissue mapping and processing are presently employed by members of the American College of Mohs Micrographic Surgery and Cutaneous Oncology. METHODS Five hundred eighty surveys of eight questions regarding different techniques used in Mohs tissue mapping and processing were mailed out to Mohs micrographic surgeons registered with the American College of Mohs Micrographic Surgery and Cutaneous Oncology. A total of 310 responses (53%) were collected between October and December 2002. The results were tabulated and analyzed. RESULTS Most Mohs micrographic surgeons personally prepare the map of the tissue in relationship to the patient (66.5%). A hand-drawn picture with standard orientations is most frequently used to map and orient a tissue specimen (69.4%). Histotechnicians usually prepare the tissue specimen for cryostat processing (63.5%). A heat extractor and/or tissue cuts or “slits” are the preferred methods used to flatten tissue by 52.9% of respondents. Hematoxylin and eosin is the stain that is most commonly used (82.6%). Approximately 50% of Mohs micrographic surgeons cut the excised specimen from the first stage into two separate pieces. Each tissue piece is then commonly processed into three to six representative serial sections per glass slide (68.1%). These sections are most commonly cut at 5 to 6 μm (53.9%) and less frequently at 4 μm (21.9%). CONCLUSION There is variability in mapping and processing techniques employed Mohs micrographic surgeons and their histotechnicians. As long as the integrity of each step of Mohs tissue mapping and processing is preserved, the high cure rate of the technique should be maintained.