Transposition Flaps: Principles and Locations.

BACKGROUND: Transposition flaps are frequently used to repair defects of the head and neck after tumor extirpation with Mohs micrographic surgery. OBJECTIVE: To review the basic principles underlying single-stage transposition flaps and also their utility relative to location on the head and neck. MATERIALS AND METHODS: A review of the literature on transposition flaps was performed with specific reference to the principles of single-stage transposition flaps, including rhomboid flaps and their variations, multilobed flaps, and the locations where transposition flaps are frequently executed on the head and neck. RESULTS: Numerous articles have been written with regard to the techniques for designing and executing transposition flaps. The primary advantages of transposition flaps include less undermining as compared to large sliding flaps and the superior ability to displace tension away from the defect and from free margins. Optimal cosmesis with these flaps can be achieved with appropriate sizing of flaps (or lobes), appropriate undermining, and meticulous suturing. CONCLUSION: The versatility of transposition flaps makes them optimal for repair of defects on the head and neck and utilization of the outlined key principles and techniques aid in achieving an aesthetic result.

Distinction of melanoma in situ from solar lentigo on sun-damaged skin using morphometrics and MITF immunohistochemistry.

Distinction between melanoma in situ (MIS) and solar lentigo (SL) on chronically sun-damaged skin (CSDS) by hematoxylin and eosin (H&E) criteria alone can be difficult and in frozen section (FS) material, may be virtually impossible without immunohistochemistry (IHC). In this study, we used microphthalmia-associated transcription factor (MITF) IHC-directed image analysis to compare melanocyte nuclear morphometrics of MIS, SL, and sections of sun-damaged skin from redundant tissue acquired during Mohs micrographic surgery. The mean nuclear diameter and melanocytic density figures for MIS were greater than those for SL and CSDS by both independent t-test and analysis of variance statistics. No significant differences in these parameters were found between SL and sun-damaged skin. Cutoff values that favored MIS over SL included melanocyte density ≥10 nuclei per 200 µm, nuclear diameter ≥9 µm, and a product of density and diameter of 80 or more, as each of these values was associated with 100% specificity of MIS diagnosis. Our results suggest that image analysis of melanocytes labeled with MITF IHC can be used to produce morphometric data that distinguish MIS from SL and CSDS. The study was conducted using permanent sections, but previous studies with FSs indicate that the findings would apply to FSs as well. Quantitative assessment of melanocytic parameters using image analysis will likely become increasingly important as an adjunct to conventional histopathology for the diagnosis and surgical management of MIS on sun-damaged skin.