Abstract: |
The processing of a Mohs wedge-shaped excision poses technical challenges due to tissue planes of variable consistency. For example, on cross-section, the eyelid comprises epidermis, dermis, fat, muscle, tarsus, and conjunctiva. Similarly, the presence of mucosa or cartilage complicates processing of wedge-shaped excisions from the lip or alar and helical rims, respectively. Lateral margins that are perpendicularly oriented rather than bevelled, as in traditional Mohs sections, makes the processing of Mohs wedge-shaped excisions more difficult. The modified technique that we have described facilitates processing and evaluation of the entire relevant surgical margins. The advantages of this technique include preservation of proper tissue orientation and architecture, because there is minimal tissue manipulation (no grossing). Additionally, thisstraightforward approach is easy for the Mohshistotechnician to conceptualize and for the Mohs surgeon to interpret. Moreover, this technique does not require any specialized laboratory equipment or supplies. The disadvantages of this technique include a slightly longer tissue preparation time (due to the requirement of two thaw cycles) and the need for a technically skilled histotechnician. Precise initial sectioning is essential, because each deeper cut into the block eliminates what represents a true Mohs margin. In conclusion, we describe a modified histologic embedding technique to overcome obstacles with traditional Mohs wedge excision processing and facilitate evaluation of all relevant surgical margins with Mohs frozen sections. We have found that this modified technique represents an accurate and conceptually simple approach to the processing of Mohs full-thickness wedge excisions. © 2009 by the American Society for Dermatologic Surgery, Inc. |