Hugh M. Gloster, Jr, MD, 3590 Lucille Dr, suite 1600, Cincinnati, Ohio 45213, Telephone: 513-475-7630, Fax: 513-487-1000; E-mail:
Purpose: The purpose of this manuscript is to describe a method of simultaneous processing multiple small tissue specimens of similar consistency from the same patient, which allows the Mohs surgeon to view two or more specimens at once on one slide.
Conclusions: This technique reduces the number of glass slides utilized and increase the rapidity with which frozen sections can be prepared and examined, thus adding to the growing body of literature describing more efficient measures of frozen section processing in Mohs Micrographic Surgery.
It is not uncommon for a patient to present to the Mohs surgeon for the treatment of more than one tumor on the same operative day. Embedding, sectioning, and mounting each specimen separately on different glass slides can be time-consuming for the histotechnician and wasteful of slides, especially if each excisional specimen is divided into two or more pieces prior to frozen section processing. Alternatively, small (usually 2 to 4 specimens depending on their size) excisional specimens from anatomic sites of similar consistency on the same patient may be sectioned together and mounted on one glass slide by the single section method. The single section method saves time by omitting the division each specimen into smaller sections, which reduces the number of specimens that must be cut, stained, and cover slipped by the technician and interpreted by the surgeon [1-3]. This method permits the surgeon to view all of the specimens at once and increases the rapidity of frozen section preparation and examination (Figure 1).
The same concept described above can be applied to instances when, after microscopically examining and mapping an excised layer of tissue, it necessary to re-excise multiple, small pieces of tissue at the periphery of the defect due to residual epidermal tumor (Figure 2). This scenario commonly occurs during the treatment of certain neoplasms that exhibit subclinical horizontal spread through the epidermis, such as squamous cell carcinoma in situ, malignant melanoma in situ, or multifocal superficial basal cell carcinoma. Multiple small tissue specimens (typically two to four in number) may be embedded together in frozen
The simultaneous processing of multiple specimens is ideally suited for small and medium sized specimens of similar consistency, which usually occurs when specimens are excised from the same anatomic area. In other words, the specimens should have similar dermal thickness and adipose content. Modest sized specimens of similar consistency will freeze at a similar rate and yield higher quality frozen sections without holes or tears. The number of specimens that may be sectioned and mounted on a single glass slide depends on the number and size of each of the specimens, since they all must fit on one 2.5 x 7.5 cm glass slide together. The diameter of the cryostat chuck is not a size-limiting factor, because specimens that are larger than the chuck may be successfully processed and sectioned if the specimen head can travel full circle across the blade and back up to its original position.
There are potential risks that are involved with the simultaneous processing of multiple specimens, particularly for an inexperienced histotechnician. First, there is the potential of deeper facing of the tissue block in order to achieve complete
In conclusion, the simultaneous processing multiple specimens from the same patient allows the Mohs surgeon to view two or more specimens at once on one slide. Also, since more than one horizontal section frequently can be mounted on one slide, the surgeon may rapidly examine successively deeper sections into the tissue block. This technique reduces the number of glass slides utilized and increase the rapidity with which frozen sections can be prepared and examined.
- Randle HN, Zitelli J, Brodland DG, Roenigk, RK. Histologic preparation for Mohs micrographic surgery – the single section method. J Dermatol Surg Oncol. 1993;19(6): 522-524.
- Kimyai-Asadi A, Goldberg LH, Nemeth A, Friedman PM, Jih MH. Mohs micrographic surgery for elliptical excisions of skin tumors: a surgical and histologic study. Dermatol Surg. 2004;30(10):1310-1317.
- Gloster HM. Surgical pearl: large single sections in Mohs micrographic surgery. J Am Acad Dermatol. 2003;49(3):506-508.
- Gloster HM, Taylor AF. Surgical pearl: the use of multiple different tissue specimens on the same glass slide to enhance the efficiency of frozen section preparation in Mohs micrographic surgery. J Am Acad Dermatol. 1998;39(1):107-108.